From c73797592ef9558f89b6de9ed0b23066767fbcee Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Mon, 29 Apr 2024 13:57:46 -0500
Subject: [PATCH 01/23] GPU Support

---
 Dockerfile                | 16 +++++--
 README.md                 |  5 ++
 scripts/build_proc_cpu.sh | 12 -----
 scripts/build_proc_gpu.sh | 98 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 116 insertions(+), 15 deletions(-)
 create mode 100644 scripts/build_proc_gpu.sh

diff --git a/Dockerfile b/Dockerfile
index 69ec3e1..a5de4d2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -22,9 +22,18 @@ ENV PYTHONDONTWRITEBYTECODE=true
 ENV PROC_HOME=/home/conda/back-projection
 ENV MYHOME=/home/conda
 
-RUN apt-get update && apt-get install -y --no-install-recommends unzip vim curl build-essential gfortran libfftw3-dev && \
+RUN apt-get update && apt-get install -y --no-install-recommends unzip vim curl build-essential gfortran libfftw3-dev nvidia-driver-535 software-properties-common && \
     apt-get clean && rm -rf /var/lib/apt/lists/*
 
+RUN wget https://developer.download.nvidia.com/compute/cuda/12.4.1/local_installers/cuda-repo-debian12-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
+    dpkg -i cuda-repo-debian12-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
+    cp /var/cuda-repo-debian12-12-4-local/cuda-*-keyring.gpg /usr/share/keyrings/ && \
+    add-apt-repository contrib && \
+    apt-get update && \
+    apt-get -y install cuda-toolkit-12-4 && \
+    nvcc --version
+
+ARG USE_GPU=yes
 ARG CONDA_UID=1000
 ARG CONDA_GID=1000
 ARG BACK_PROJECTION_TAG=0.2.0
@@ -36,7 +45,6 @@ RUN groupadd -g "${CONDA_GID}" --system conda && \
     echo ". /opt/conda/etc/profile.d/conda.sh" >> /home/conda/.profile && \
     echo "conda activate base" >> /home/conda/.profile
 
-
 USER ${CONDA_UID}
 SHELL ["/bin/bash", "-l", "-c"]
 WORKDIR /home/conda/
@@ -47,10 +55,12 @@ RUN curl -sL https://github.com/ASFHyP3/back-projection/archive/refs/tags/v${BAC
     rm ./back-projection.tar.gz && \
     rm -rf ./back-projection/fft
 
-COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc_cpu.sh ./back-projection
+COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc_cpu.sh ./scripts/build_proc_gpu.sh ./back-projection
 RUN cd /home/conda/back-projection && \
     chmod +x ./build_proc_cpu.sh && \
+    chmod +x ./build_proc_gpu.sh && \
     ./build_proc_cpu.sh && \
+    if [[ $arg == "yes" ]] ; echo "Skipping GPU build..." ; ./build_proc_cpu.sh && \
     cd /home/conda/
 
 COPY --chown=${CONDA_UID}:${CONDA_GID} . /hyp3-back-projection/
diff --git a/README.md b/README.md
index 9f19547..701519c 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,8 @@
 # HyP3 back-projection
 
 HyP3 plugin for back-projection processing
+
+### GPU Setup:
+In order for Docker to be able to use the host's GPU, the host must have the [NVIDIA Container Toolkit](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/index.html) installed and configured. 
+The process is different for different OS's and Linux distros. The setup process for the most common distros, including Ubuntu, 
+can be found [here](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/install-guide.html#configuration). Make sure to follow the [Docker configuration steps](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/install-guide.html#configuration) after installing the package. **This process is not necessary when running in AWS while using an EC2 image made with GPU support.**
\ No newline at end of file
diff --git a/scripts/build_proc_cpu.sh b/scripts/build_proc_cpu.sh
index e5bed5e..8578e68 100644
--- a/scripts/build_proc_cpu.sh
+++ b/scripts/build_proc_cpu.sh
@@ -19,10 +19,6 @@ gfortran -c processsubcpu.f90 backprojectcpusub.f90 bounds.f90 orbitrangetime.f9
 gcc -o sentinel_raw_process_cpu sentinel_raw_process_cpu.o decode_line_memory.o processsubcpu.o backprojectcpusub.o azimuth_compress_cpu.o bounds.o orbitrangetime.o latlon.o intp_orbit.o radar_to_xyz.o unitvec.o tcnbasis.o curvature.o cross.o orbithermite.o filelen.o io.o sentineltimingsub.o getburststatevectors.o $FFTW_LIB -lgfortran -lgomp -lm -lrt -lpthread
 echo 'built sentinel_raw_process_cpu'
 
-# nvcc -o howmanygpus howmanygpus.cu
-#
-# echo 'built howmanygpus'
-
 cd geo2rdr
 gfortran -o estimatebaseline estimatebaseline.f90 intp_orbit.f90 latlon.f90 orbithermite.f -ffixed-line-length-none
 
@@ -79,20 +75,12 @@ cd ..
 
 echo 'built snaphu'
 
-# nvcc -o gpu_arch gpu_arch.cu
-# echo 'built gpu architecture probe'
-#
-# ./gpu_arch | cat > GPU_ARCH; source ./GPU_ARCH; rm GPU_ARCH
-
 cd sentinel
 
 gcc -c filelen.c io.c sentinel_raw_process.c decode_line_memory.c -lm -fopenmp
 
 echo 'built raw_process components in sentinel'
 
-# nvcc -gencode arch=compute_$GPU_ARCH,code=sm_$GPU_ARCH -c azimuth_compress.cu -Wno-deprecated-gpu-targets
-
 gfortran -c processsub.f90 backprojectgpusub.f90 bounds.f90 orbitrangetime.f90 latlon.f90 intp_orbit.f90 radar_to_xyz.f90 unitvec.f90 tcnbasis.f90 curvature.f90 cross.f90 orbithermite.f sentineltimingsub.f90 getburststatevectors.f90 -ffixed-line-length-none -fopenmp
 
-# nvcc -o sentinel_raw_process sentinel_raw_process.o decode_line_memory.o processsub.o backprojectgpusub.o azimuth_compress.o bounds.o orbitrangetime.o latlon.o intp_orbit.o radar_to_xyz.o unitvec.o tcnbasis.o curvature.o cross.o orbithermite.o filelen.o io.o sentineltimingsub.o getburststatevectors.o $FFTW_LIB -lstdc++ -lgfortran -lgomp
 cd ..
diff --git a/scripts/build_proc_gpu.sh b/scripts/build_proc_gpu.sh
new file mode 100644
index 0000000..5f99e78
--- /dev/null
+++ b/scripts/build_proc_gpu.sh
@@ -0,0 +1,98 @@
+#!/bin/bash
+
+MULTIARCH_DIR=/usr/lib/$(gcc -print-multiarch)
+FFTW_LIB=$MULTIARCH_DIR/libfftw3f.a
+echo 'using FFTW library:' $FFTW_LIB
+
+# Works
+cd DEM
+gfortran -o mosaicDEM mosaicDEM.f90
+gfortran -o createspecialdem createspecialdem.f90
+gfortran -o geoid2008_ellipsoid_interpolate geoid2008_ellipsoid_interpolate.f90
+cd ..
+
+cd sentinel
+gfortran -o createslc createslc.f90
+gcc -c azimuth_compress_cpu.c -lm -fopenmp
+gcc -c filelen.c io.c sentinel_raw_process_cpu.c decode_line_memory.c -lm -fopenmp
+gfortran -c processsubcpu.f90 backprojectcpusub.f90 bounds.f90 orbitrangetime.f90 latlon.f90 intp_orbit.f90 radar_to_xyz.f90 unitvec.f90 tcnbasis.f90 curvature.f90 cross.f90 orbithermite.f sentineltimingsub.f90 getburststatevectors.f90 -ffixed-line-length-none -fopenmp
+gcc -o sentinel_raw_process_cpu sentinel_raw_process_cpu.o decode_line_memory.o processsubcpu.o backprojectcpusub.o azimuth_compress_cpu.o bounds.o orbitrangetime.o latlon.o intp_orbit.o radar_to_xyz.o unitvec.o tcnbasis.o curvature.o cross.o orbithermite.o filelen.o io.o sentineltimingsub.o getburststatevectors.o $FFTW_LIB -lgfortran -lgomp -lm -lrt -lpthread
+echo 'built sentinel_raw_process_cpu'
+
+nvcc -o howmanygpus howmanygpus.cu
+
+echo 'built howmanygpus'
+
+cd geo2rdr
+gfortran -o estimatebaseline estimatebaseline.f90 intp_orbit.f90 latlon.f90 orbithermite.f -ffixed-line-length-none
+
+echo 'finished with sentinel directory'
+
+cd ../..
+cd util
+gcc -c io.c
+gfortran -o nbymi2 nbymi2.f io.o
+gfortran -c lsq.f90
+gfortran -o regressheight regressheight.f90 lsq.o
+
+echo 'finished with util directory'
+
+cd ..
+cd int
+gfortran -o findrefpoints findrefpoints.f90
+gfortran -o refpointsfromsim refpointsfromsim.f90
+
+echo 'built findrefpoints'
+
+gcc -c ../util/filelen.c
+
+echo 'compiled filelen'
+
+gfortran -o crossmul crossmul.f90 filelen.o $FFTW_LIB -fopenmp -lrt -lpthread
+
+echo 'built crossmul'
+
+gfortran -o makecc makecc.f90 filelen.o -fopenmp -lrt -lpthread
+
+echo 'finished with int directory'
+
+cd ..
+cd sbas
+gfortran -o sbas sbas.f90 svd.f90 -fopenmp -lrt -lpthread
+echo 'built sbas in sbas directory'
+
+cd ..
+cd ps
+gfortran -o cosine_sim cosine_sim.f90 -fopenmp $FFTW_LIB
+gfortran -o psinterp psinterp.f90 -fopenmp
+echo 'Built cosine_sim and psinterp in ps directory'
+
+cd ..
+tar xf snaphu_v2_0b0_0_0.tar
+cd snaphu_v2.0b0.0.0/src
+make CFLAGS=-O3 -s
+
+cd ..
+if [ -e $PROC_HOME/bin ]; then echo "copying snaphu"; else mkdir $PROC_HOME/bin; fi
+cp bin/snaphu $PROC_HOME/bin/snaphu
+cd ..
+
+echo 'built snaphu'
+
+# nvcc -o gpu_arch gpu_arch.cu
+# echo 'built gpu architecture probe'
+
+# ./gpu_arch | cat > GPU_ARCH; source ./GPU_ARCH; rm GPU_ARCH
+
+cd sentinel
+
+gcc -c filelen.c io.c sentinel_raw_process.c decode_line_memory.c -lm -fopenmp
+
+echo 'built raw_process components in sentinel'
+
+nvcc -gencode arch=compute_89,code=sm_89 -c azimuth_compress.cu -Wno-deprecated-gpu-targets
+
+gfortran -c processsub.f90 backprojectgpusub.f90 bounds.f90 orbitrangetime.f90 latlon.f90 intp_orbit.f90 radar_to_xyz.f90 unitvec.f90 tcnbasis.f90 curvature.f90 cross.f90 orbithermite.f sentineltimingsub.f90 getburststatevectors.f90 -ffixed-line-length-none -fopenmp
+
+nvcc -o sentinel_raw_process sentinel_raw_process.o decode_line_memory.o processsub.o backprojectgpusub.o azimuth_compress.o bounds.o orbitrangetime.o latlon.o intp_orbit.o radar_to_xyz.o unitvec.o tcnbasis.o curvature.o cross.o orbithermite.o filelen.o io.o sentineltimingsub.o getburststatevectors.o $FFTW_LIB -lstdc++ -lgfortran -lgomp
+cd ..

From ae59337bdef8948b2ee0239216e6ea21f0d355d9 Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Mon, 29 Apr 2024 16:21:00 -0500
Subject: [PATCH 02/23] Move CUDA installation to script for conditional
 install

---
 Dockerfile              | 30 ++++++++++++++++--------------
 scripts/install_cuda.sh | 15 +++++++++++++++
 2 files changed, 31 insertions(+), 14 deletions(-)
 create mode 100644 scripts/install_cuda.sh

diff --git a/Dockerfile b/Dockerfile
index a5de4d2..1a5f0c8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,22 +18,14 @@ LABEL org.opencontainers.image.documentation="https://hyp3-docs.asf.alaska.edu"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
+ENV USEGPU="yes"
 ENV PYTHONDONTWRITEBYTECODE=true
 ENV PROC_HOME=/home/conda/back-projection
 ENV MYHOME=/home/conda
 
-RUN apt-get update && apt-get install -y --no-install-recommends unzip vim curl build-essential gfortran libfftw3-dev nvidia-driver-535 software-properties-common && \
+RUN apt-get update && apt-get install -y --no-install-recommends unzip vim curl build-essential gfortran libfftw3-dev nvidia-driver-535 && \
     apt-get clean && rm -rf /var/lib/apt/lists/*
 
-RUN wget https://developer.download.nvidia.com/compute/cuda/12.4.1/local_installers/cuda-repo-debian12-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
-    dpkg -i cuda-repo-debian12-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
-    cp /var/cuda-repo-debian12-12-4-local/cuda-*-keyring.gpg /usr/share/keyrings/ && \
-    add-apt-repository contrib && \
-    apt-get update && \
-    apt-get -y install cuda-toolkit-12-4 && \
-    nvcc --version
-
-ARG USE_GPU=yes
 ARG CONDA_UID=1000
 ARG CONDA_GID=1000
 ARG BACK_PROJECTION_TAG=0.2.0
@@ -45,22 +37,32 @@ RUN groupadd -g "${CONDA_GID}" --system conda && \
     echo ". /opt/conda/etc/profile.d/conda.sh" >> /home/conda/.profile && \
     echo "conda activate base" >> /home/conda/.profile
 
-USER ${CONDA_UID}
 SHELL ["/bin/bash", "-l", "-c"]
+
+COPY ./scripts/install_cuda.sh ./
+RUN chmod +x ./install_cuda.sh
+RUN if [[ $USEGPU == "yes" ]] ; then ./install_cuda.sh ; else echo "Skipping CUDA install..." ; fi
+
+USER ${CONDA_UID}
 WORKDIR /home/conda/
 
+RUN if [[ $USEGPU == "yes" ]] ; then \
+    echo "export PATH="/usr/local/cuda-12.4/bin:$PATH"" >> .bashrc && \
+    echo "export LD_LIBRARY_PATH="/usr/local/cuda-12.4/lib64:$LD_LIBRARY_PATH"" >> .bashrc \
+    ; else echo "Skipping exporting CUDA path." ; fi
+
 RUN curl -sL https://github.com/ASFHyP3/back-projection/archive/refs/tags/v${BACK_PROJECTION_TAG}.tar.gz > ./back-projection.tar.gz && \
     mkdir -p ./back-projection && \
     tar -xvf ./back-projection.tar.gz -C ./back-projection/ --strip=1 && \
     rm ./back-projection.tar.gz && \
     rm -rf ./back-projection/fft
 
-COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc_cpu.sh ./scripts/build_proc_gpu.sh ./back-projection
+COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc_cpu.sh ./back-projection
+COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc_gpu.sh ./back-projection
 RUN cd /home/conda/back-projection && \
     chmod +x ./build_proc_cpu.sh && \
     chmod +x ./build_proc_gpu.sh && \
-    ./build_proc_cpu.sh && \
-    if [[ $arg == "yes" ]] ; echo "Skipping GPU build..." ; ./build_proc_cpu.sh && \
+    if [[ $USEGPU == "yes" ]] ; then ./build_proc_cpu.sh ; else ./build_proc_cpu.sh ; fi && \
     cd /home/conda/
 
 COPY --chown=${CONDA_UID}:${CONDA_GID} . /hyp3-back-projection/
diff --git a/scripts/install_cuda.sh b/scripts/install_cuda.sh
new file mode 100644
index 0000000..1aceecd
--- /dev/null
+++ b/scripts/install_cuda.sh
@@ -0,0 +1,15 @@
+# Script to install nvidia drivers and the nvidia cuda toolkit.
+
+# Install Cuda Toolkit 12.4
+# Source: https://developer.nvidia.com/cuda-downloads?target_os=Linux&target_arch=x86_64&Distribution=Ubuntu&target_version=20.04&target_type=deb_local
+wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-ubuntu2004.pin && \
+mv cuda-ubuntu2004.pin /etc/apt/preferences.d/cuda-repository-pin-600 && \
+wget https://developer.download.nvidia.com/compute/cuda/12.4.1/local_installers/cuda-repo-ubuntu2004-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
+dpkg -i cuda-repo-ubuntu2004-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
+cp /var/cuda-repo-ubuntu2004-12-4-local/cuda-*-keyring.gpg /usr/share/keyrings/ && \
+apt-get update && \
+apt-get -y install cuda-toolkit-12-4
+
+# Add Cuda Toolkit binaries to the Path.
+echo "export PATH="/usr/local/cuda-12.4/bin:$PATH"" >> .bashrc
+echo "export LD_LIBRARY_PATH="/usr/local/cuda-12.4/lib64:$LD_LIBRARY_PATH"" >> .bashrc
\ No newline at end of file

From f697e193a162e49137596799733224a368846a3d Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Mon, 29 Apr 2024 16:24:33 -0500
Subject: [PATCH 03/23] removed path export

---
 scripts/install_cuda.sh | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/scripts/install_cuda.sh b/scripts/install_cuda.sh
index 1aceecd..2102f9e 100644
--- a/scripts/install_cuda.sh
+++ b/scripts/install_cuda.sh
@@ -9,7 +9,3 @@ dpkg -i cuda-repo-ubuntu2004-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
 cp /var/cuda-repo-ubuntu2004-12-4-local/cuda-*-keyring.gpg /usr/share/keyrings/ && \
 apt-get update && \
 apt-get -y install cuda-toolkit-12-4
-
-# Add Cuda Toolkit binaries to the Path.
-echo "export PATH="/usr/local/cuda-12.4/bin:$PATH"" >> .bashrc
-echo "export LD_LIBRARY_PATH="/usr/local/cuda-12.4/lib64:$LD_LIBRARY_PATH"" >> .bashrc
\ No newline at end of file

From 84255e8ed0301a78c7be21588223013b060e0170 Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Mon, 29 Apr 2024 16:28:30 -0500
Subject: [PATCH 04/23] removed gpuarch code (wont work during docker build)

---
 scripts/build_proc_gpu.sh | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/scripts/build_proc_gpu.sh b/scripts/build_proc_gpu.sh
index 5f99e78..7c3a6c2 100644
--- a/scripts/build_proc_gpu.sh
+++ b/scripts/build_proc_gpu.sh
@@ -79,11 +79,6 @@ cd ..
 
 echo 'built snaphu'
 
-# nvcc -o gpu_arch gpu_arch.cu
-# echo 'built gpu architecture probe'
-
-# ./gpu_arch | cat > GPU_ARCH; source ./GPU_ARCH; rm GPU_ARCH
-
 cd sentinel
 
 gcc -c filelen.c io.c sentinel_raw_process.c decode_line_memory.c -lm -fopenmp

From de985361e8e314e81ff9556165aec587c8f182a2 Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Mon, 29 Apr 2024 16:29:29 -0500
Subject: [PATCH 05/23] updated changelog

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 68e8298..f9493f4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [PEP 440](https://www.python.org/dev/peps/pep-0440/)
 and uses [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.4.0]
+
+### Added
+* Support for GPU accelerated processing using CUDA.
 
 ## [0.3.0]
 

From f8c4210e126f64dca1f67701e1e38a3a757b69d9 Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Tue, 30 Apr 2024 12:28:16 -0500
Subject: [PATCH 06/23] change things to not use gpu by default

---
 Dockerfile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Dockerfile b/Dockerfile
index 1a5f0c8..fe9a29b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,7 +18,7 @@ LABEL org.opencontainers.image.documentation="https://hyp3-docs.asf.alaska.edu"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
-ENV USEGPU="yes"
+ENV USEGPU="no"
 ENV PYTHONDONTWRITEBYTECODE=true
 ENV PROC_HOME=/home/conda/back-projection
 ENV MYHOME=/home/conda

From 53f4a367f54fdab0cb5fed7785abc40222b6828d Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Tue, 7 May 2024 08:55:23 -0500
Subject: [PATCH 07/23] combine cpu/gpu build proc

---
 Dockerfile                                   | 15 ++--
 scripts/{build_proc_cpu.sh => build_proc.sh} | 13 +++
 scripts/build_proc_gpu.sh                    | 93 --------------------
 src/hyp3_back_projection/back_projection.py  | 17 ++--
 4 files changed, 32 insertions(+), 106 deletions(-)
 rename scripts/{build_proc_cpu.sh => build_proc.sh} (82%)
 delete mode 100644 scripts/build_proc_gpu.sh

diff --git a/Dockerfile b/Dockerfile
index 2f23a3c..8856b7f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,7 +18,9 @@ LABEL org.opencontainers.image.documentation="https://hyp3-docs.asf.alaska.edu"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
-ENV USEGPU="no"
+ARG USEGPU="false"
+ENV USEGPU=${USEGPU}
+
 ENV PYTHONDONTWRITEBYTECODE=true
 ENV PROC_HOME=/home/conda/back-projection
 ENV MYHOME=/home/conda
@@ -46,7 +48,7 @@ RUN if [[ $USEGPU == "yes" ]] ; then ./install_cuda.sh ; else echo "Skipping CUD
 USER ${CONDA_UID}
 WORKDIR /home/conda/
 
-RUN if [[ $USEGPU == "yes" ]] ; then \
+RUN if [[ $USEGPU == "true" ]] ; then \
     echo "export PATH="/usr/local/cuda-12.4/bin:$PATH"" >> .bashrc && \
     echo "export LD_LIBRARY_PATH="/usr/local/cuda-12.4/lib64:$LD_LIBRARY_PATH"" >> .bashrc \
     ; else echo "Skipping exporting CUDA path." ; fi
@@ -57,13 +59,10 @@ RUN curl -sL https://github.com/ASFHyP3/back-projection/archive/refs/tags/v${BAC
     rm ./back-projection.tar.gz && \
     rm -rf ./back-projection/fft
 
-COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc_cpu.sh ./back-projection
-COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc_gpu.sh ./back-projection
+COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc.sh ./back-projection
 RUN cd /home/conda/back-projection && \
-    chmod +x ./build_proc_cpu.sh && \
-    chmod +x ./build_proc_gpu.sh && \
-    if [[ $USEGPU == "yes" ]] ; then ./build_proc_cpu.sh ; else ./build_proc_cpu.sh ; fi && \
-    ./build_proc_cpu.sh && \
+    chmod +x ./build_proc.sh && \
+    ./build_proc.sh && \
     find $PROC_HOME -type f -name "*.py" -exec chmod +x {} + && \
     cd /home/conda/
 
diff --git a/scripts/build_proc_cpu.sh b/scripts/build_proc.sh
similarity index 82%
rename from scripts/build_proc_cpu.sh
rename to scripts/build_proc.sh
index ef80fc2..f3cfae1 100644
--- a/scripts/build_proc_cpu.sh
+++ b/scripts/build_proc.sh
@@ -19,6 +19,11 @@ gfortran -c processsubcpu.f90 backprojectcpusub.f90 bounds.f90 orbitrangetime.f9
 gcc -o sentinel_raw_process_cpu sentinel_raw_process_cpu.o decode_line_memory.o processsubcpu.o backprojectcpusub.o azimuth_compress_cpu.o bounds.o orbitrangetime.o latlon.o intp_orbit.o radar_to_xyz.o unitvec.o tcnbasis.o curvature.o cross.o orbithermite.o filelen.o io.o sentineltimingsub.o getburststatevectors.o $FFTW_LIB -lgfortran -lgomp -lm -lrt -lpthread
 echo 'built sentinel_raw_process_cpu'
 
+if [[ "$USEGPU" == "true" ]]; then
+    nvcc -o howmanygpus howmanygpus.cu
+    echo 'built howmanygpus'
+fi
+
 cd geo2rdr
 gfortran -o estimatebaseline estimatebaseline.f90 intp_orbit.f90 latlon.f90 orbithermite.f -ffixed-line-length-none
 
@@ -82,6 +87,14 @@ gcc -c filelen.c io.c sentinel_raw_process.c decode_line_memory.c -lm -fopenmp
 
 echo 'built raw_process components in sentinel'
 
+if [[ "$USEGPU" == "true" ]]; then
+    nvcc -gencode arch=compute_89,code=sm_89 -c azimuth_compress.cu -Wno-deprecated-gpu-targets
+fi
+
 gfortran -c processsub.f90 backprojectgpusub.f90 bounds.f90 orbitrangetime.f90 latlon.f90 intp_orbit.f90 radar_to_xyz.f90 unitvec.f90 tcnbasis.f90 curvature.f90 cross.f90 orbithermite.f sentineltimingsub.f90 getburststatevectors.f90 -ffixed-line-length-none -fopenmp
 
+if [[ "$USEGPU" == "true" ]]; then
+    nvcc -o sentinel_raw_process sentinel_raw_process.o decode_line_memory.o processsub.o backprojectgpusub.o azimuth_compress.o bounds.o orbitrangetime.o latlon.o intp_orbit.o radar_to_xyz.o unitvec.o tcnbasis.o curvature.o cross.o orbithermite.o filelen.o io.o sentineltimingsub.o getburststatevectors.o $FFTW_LIB -lstdc++ -lgfortran -lgomp
+fi
+
 cd ..
diff --git a/scripts/build_proc_gpu.sh b/scripts/build_proc_gpu.sh
deleted file mode 100644
index 7c3a6c2..0000000
--- a/scripts/build_proc_gpu.sh
+++ /dev/null
@@ -1,93 +0,0 @@
-#!/bin/bash
-
-MULTIARCH_DIR=/usr/lib/$(gcc -print-multiarch)
-FFTW_LIB=$MULTIARCH_DIR/libfftw3f.a
-echo 'using FFTW library:' $FFTW_LIB
-
-# Works
-cd DEM
-gfortran -o mosaicDEM mosaicDEM.f90
-gfortran -o createspecialdem createspecialdem.f90
-gfortran -o geoid2008_ellipsoid_interpolate geoid2008_ellipsoid_interpolate.f90
-cd ..
-
-cd sentinel
-gfortran -o createslc createslc.f90
-gcc -c azimuth_compress_cpu.c -lm -fopenmp
-gcc -c filelen.c io.c sentinel_raw_process_cpu.c decode_line_memory.c -lm -fopenmp
-gfortran -c processsubcpu.f90 backprojectcpusub.f90 bounds.f90 orbitrangetime.f90 latlon.f90 intp_orbit.f90 radar_to_xyz.f90 unitvec.f90 tcnbasis.f90 curvature.f90 cross.f90 orbithermite.f sentineltimingsub.f90 getburststatevectors.f90 -ffixed-line-length-none -fopenmp
-gcc -o sentinel_raw_process_cpu sentinel_raw_process_cpu.o decode_line_memory.o processsubcpu.o backprojectcpusub.o azimuth_compress_cpu.o bounds.o orbitrangetime.o latlon.o intp_orbit.o radar_to_xyz.o unitvec.o tcnbasis.o curvature.o cross.o orbithermite.o filelen.o io.o sentineltimingsub.o getburststatevectors.o $FFTW_LIB -lgfortran -lgomp -lm -lrt -lpthread
-echo 'built sentinel_raw_process_cpu'
-
-nvcc -o howmanygpus howmanygpus.cu
-
-echo 'built howmanygpus'
-
-cd geo2rdr
-gfortran -o estimatebaseline estimatebaseline.f90 intp_orbit.f90 latlon.f90 orbithermite.f -ffixed-line-length-none
-
-echo 'finished with sentinel directory'
-
-cd ../..
-cd util
-gcc -c io.c
-gfortran -o nbymi2 nbymi2.f io.o
-gfortran -c lsq.f90
-gfortran -o regressheight regressheight.f90 lsq.o
-
-echo 'finished with util directory'
-
-cd ..
-cd int
-gfortran -o findrefpoints findrefpoints.f90
-gfortran -o refpointsfromsim refpointsfromsim.f90
-
-echo 'built findrefpoints'
-
-gcc -c ../util/filelen.c
-
-echo 'compiled filelen'
-
-gfortran -o crossmul crossmul.f90 filelen.o $FFTW_LIB -fopenmp -lrt -lpthread
-
-echo 'built crossmul'
-
-gfortran -o makecc makecc.f90 filelen.o -fopenmp -lrt -lpthread
-
-echo 'finished with int directory'
-
-cd ..
-cd sbas
-gfortran -o sbas sbas.f90 svd.f90 -fopenmp -lrt -lpthread
-echo 'built sbas in sbas directory'
-
-cd ..
-cd ps
-gfortran -o cosine_sim cosine_sim.f90 -fopenmp $FFTW_LIB
-gfortran -o psinterp psinterp.f90 -fopenmp
-echo 'Built cosine_sim and psinterp in ps directory'
-
-cd ..
-tar xf snaphu_v2_0b0_0_0.tar
-cd snaphu_v2.0b0.0.0/src
-make CFLAGS=-O3 -s
-
-cd ..
-if [ -e $PROC_HOME/bin ]; then echo "copying snaphu"; else mkdir $PROC_HOME/bin; fi
-cp bin/snaphu $PROC_HOME/bin/snaphu
-cd ..
-
-echo 'built snaphu'
-
-cd sentinel
-
-gcc -c filelen.c io.c sentinel_raw_process.c decode_line_memory.c -lm -fopenmp
-
-echo 'built raw_process components in sentinel'
-
-nvcc -gencode arch=compute_89,code=sm_89 -c azimuth_compress.cu -Wno-deprecated-gpu-targets
-
-gfortran -c processsub.f90 backprojectgpusub.f90 bounds.f90 orbitrangetime.f90 latlon.f90 intp_orbit.f90 radar_to_xyz.f90 unitvec.f90 tcnbasis.f90 curvature.f90 cross.f90 orbithermite.f sentineltimingsub.f90 getburststatevectors.f90 -ffixed-line-length-none -fopenmp
-
-nvcc -o sentinel_raw_process sentinel_raw_process.o decode_line_memory.o processsub.o backprojectgpusub.o azimuth_compress.o bounds.o orbitrangetime.o latlon.o intp_orbit.o radar_to_xyz.o unitvec.o tcnbasis.o curvature.o cross.o orbithermite.o filelen.o io.o sentineltimingsub.o getburststatevectors.o $FFTW_LIB -lstdc++ -lgfortran -lgomp
-cd ..
diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index cbbe7f2..d9b43ab 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -9,6 +9,7 @@
 from typing import Iterable, Optional
 
 from hyp3lib.aws import upload_file_to_s3
+from hyp3lib.util import string_is_true
 from shapely import unary_union
 
 from hyp3_back_projection import dem, utils
@@ -30,26 +31,29 @@ def create_param_file(dem_path: Path, dem_rsc_path: Path, output_dir: Path):
         f.write('\n'.join(lines))
 
 
-def back_project_single_granule(granule_path: Path, orbit_path: Path, work_dir: Path) -> None:
+def back_project_single_granule(granule_path: Path, orbit_path: Path, work_dir: Path, gpu: bool = False) -> None:
     """Back-project a single Sentinel-1 level-0 granule.
 
     Args:
         granule_path: Path to the granule to back-project
         orbit_path: Path to the orbit file for the granule
+        work_dir: Working directory for processing
+        gpu: Use the GPU-based version of the workflow, defaults to False
     """
     required_files = ['elevation.dem', 'elevation.dem.rsc', 'params']
     for file in required_files:
         if not (work_dir / file).exists():
             raise FileNotFoundError(f'Missing required file: {file}')
 
+    script = 'sentinel/sentinel_scene_gpu.py' if gpu else 'sentinel/sentinel_scene_cpu.py'
     args = [str(granule_path.with_suffix('')), str(orbit_path)]
-    utils.call_stanford_module('sentinel/sentinel_scene_cpu.py', args, work_dir=work_dir)
+    utils.call_stanford_module(script, args, work_dir=work_dir)
     patterns = ['*hgt*', 'dem*', 'DEM*', 'q*', '*positionburst*']
     for pattern in patterns:
         [f.unlink() for f in work_dir.glob(pattern)]
 
 
-def create_product(work_dir):
+def create_product(work_dir) -> Path:
     """Create a product zip file.
     Includes files needed for further processing (gslc, orbit, and parameter file).
 
@@ -88,7 +92,8 @@ def back_project(
     bucket: str = None,
     bucket_prefix: str = '',
     work_dir: Optional[Path] = None,
-) -> Path:
+    gpu: bool = False,
+):
     """Back-project a set of Sentinel-1 level-0 granules.
 
     Args:
@@ -100,6 +105,7 @@ def back_project(
         bucket: AWS S3 bucket for uploading the final product(s)
         bucket_prefix: Add a bucket prefix to the product(s)
         work_dir: Working directory for processing
+        gpu: Use the GPU-based version of the workflow
     """
     utils.set_creds('EARTHDATA', earthdata_username, earthdata_password)
     utils.set_creds('ESA', esa_username, esa_password)
@@ -120,7 +126,7 @@ def back_project(
     create_param_file(dem_path, dem_path.with_suffix('.dem.rsc'), work_dir)
 
     for granule_path, orbit_path in back_project_args:
-        back_project_single_granule(granule_path, orbit_path, work_dir=work_dir)
+        back_project_single_granule(granule_path, orbit_path, work_dir=work_dir, gpu=gpu)
 
     utils.call_stanford_module('util/merge_slcs.py', work_dir=work_dir)
 
@@ -146,6 +152,7 @@ def main():
     parser.add_argument('--esa-password', default=None, help="Password for ESA's Copernicus Data Space Ecosystem")
     parser.add_argument('--bucket', help='AWS S3 bucket HyP3 for upload the final product(s)')
     parser.add_argument('--bucket-prefix', default='', help='Add a bucket prefix to product(s)')
+    parser.add_argument('--gpu', type=string_is_true, default=False, help='Use the GPU-based version of the workflow.')
     parser.add_argument('granules', nargs='+', help='Level-0 S1 granule to back-project.')
     args = parser.parse_args()
 

From 1ca96e44baf90592256be5edbfeccd3f6f512a5a Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Tue, 7 May 2024 08:58:43 -0500
Subject: [PATCH 08/23] correct script name

---
 src/hyp3_back_projection/back_projection.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index d9b43ab..10a1700 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -45,7 +45,7 @@ def back_project_single_granule(granule_path: Path, orbit_path: Path, work_dir:
         if not (work_dir / file).exists():
             raise FileNotFoundError(f'Missing required file: {file}')
 
-    script = 'sentinel/sentinel_scene_gpu.py' if gpu else 'sentinel/sentinel_scene_cpu.py'
+    script = 'sentinel/sentinel_scene_multigpu.py' if gpu else 'sentinel/sentinel_scene_cpu.py'
     args = [str(granule_path.with_suffix('')), str(orbit_path)]
     utils.call_stanford_module(script, args, work_dir=work_dir)
     patterns = ['*hgt*', 'dem*', 'DEM*', 'q*', '*positionburst*']

From 9e9b0ecb5b247caf27b31adc2bd5fc0a16b9bf02 Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Tue, 7 May 2024 09:40:38 -0500
Subject: [PATCH 09/23] update arg logic

---
 src/hyp3_back_projection/back_projection.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index 10a1700..32a7119 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -9,7 +9,6 @@
 from typing import Iterable, Optional
 
 from hyp3lib.aws import upload_file_to_s3
-from hyp3lib.util import string_is_true
 from shapely import unary_union
 
 from hyp3_back_projection import dem, utils
@@ -152,7 +151,7 @@ def main():
     parser.add_argument('--esa-password', default=None, help="Password for ESA's Copernicus Data Space Ecosystem")
     parser.add_argument('--bucket', help='AWS S3 bucket HyP3 for upload the final product(s)')
     parser.add_argument('--bucket-prefix', default='', help='Add a bucket prefix to product(s)')
-    parser.add_argument('--gpu', type=string_is_true, default=False, help='Use the GPU-based version of the workflow.')
+    parser.add_argument('--gpu', default=False, action='store_true', help='Use the GPU-based version of the workflow.')
     parser.add_argument('granules', nargs='+', help='Level-0 S1 granule to back-project.')
     args = parser.parse_args()
 

From 2d9cb3eee04b546157bcab2227ddf45a9ae0b4be Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Wed, 8 May 2024 15:27:15 -0500
Subject: [PATCH 10/23] changed from yes to true

---
 Dockerfile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 8856b7f..bad764b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,7 +18,7 @@ LABEL org.opencontainers.image.documentation="https://hyp3-docs.asf.alaska.edu"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
-ARG USEGPU="false"
+ARG USEGPU="true"
 ENV USEGPU=${USEGPU}
 
 ENV PYTHONDONTWRITEBYTECODE=true
@@ -43,7 +43,7 @@ SHELL ["/bin/bash", "-l", "-c"]
 
 COPY ./scripts/install_cuda.sh ./
 RUN chmod +x ./install_cuda.sh
-RUN if [[ $USEGPU == "yes" ]] ; then ./install_cuda.sh ; else echo "Skipping CUDA install..." ; fi
+RUN if [[ $USEGPU == "true" ]] ; then ./install_cuda.sh ; else echo "Skipping CUDA install..." ; fi
 
 USER ${CONDA_UID}
 WORKDIR /home/conda/

From 1cd89b3b7fe52587711d3e7330a89b76734408ef Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Wed, 8 May 2024 15:42:03 -0500
Subject: [PATCH 11/23] make gpu not default

---
 Dockerfile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Dockerfile b/Dockerfile
index bad764b..82d5bb8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,7 +18,7 @@ LABEL org.opencontainers.image.documentation="https://hyp3-docs.asf.alaska.edu"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
-ARG USEGPU="true"
+ARG USEGPU="false"
 ENV USEGPU=${USEGPU}
 
 ENV PYTHONDONTWRITEBYTECODE=true

From 2935dfd9546bdc83fadda38e42e20cf1ddd8a028 Mon Sep 17 00:00:00 2001
From: Andrew Player <andrewplayer3@gmail.com>
Date: Wed, 8 May 2024 16:02:23 -0500
Subject: [PATCH 12/23] add cuda paths using docker's ENV rather than .bashrc

---
 Dockerfile | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 82d5bb8..deb94e2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -48,10 +48,8 @@ RUN if [[ $USEGPU == "true" ]] ; then ./install_cuda.sh ; else echo "Skipping CU
 USER ${CONDA_UID}
 WORKDIR /home/conda/
 
-RUN if [[ $USEGPU == "true" ]] ; then \
-    echo "export PATH="/usr/local/cuda-12.4/bin:$PATH"" >> .bashrc && \
-    echo "export LD_LIBRARY_PATH="/usr/local/cuda-12.4/lib64:$LD_LIBRARY_PATH"" >> .bashrc \
-    ; else echo "Skipping exporting CUDA path." ; fi
+ENV PATH="$PATH:/usr/local/cuda-12.4/bin"
+ENV LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/usr/local/cuda-12.4/lib64"
 
 RUN curl -sL https://github.com/ASFHyP3/back-projection/archive/refs/tags/v${BACK_PROJECTION_TAG}.tar.gz > ./back-projection.tar.gz && \
     mkdir -p ./back-projection && \

From 0cdbcec2076c863b9cfe125585a1eb46cf8d5bab Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Thu, 9 May 2024 08:51:00 -0500
Subject: [PATCH 13/23] use cuda base image for GPU

---
 Dockerfile              | 14 +------
 Dockerfile.gpu          | 86 +++++++++++++++++++++++++++++++++++++++++
 scripts/build_proc.sh   |  4 +-
 scripts/install_cuda.sh | 11 ------
 4 files changed, 91 insertions(+), 24 deletions(-)
 create mode 100644 Dockerfile.gpu
 delete mode 100644 scripts/install_cuda.sh

diff --git a/Dockerfile b/Dockerfile
index 8856b7f..954d99c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,14 +18,13 @@ LABEL org.opencontainers.image.documentation="https://hyp3-docs.asf.alaska.edu"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
-ARG USEGPU="false"
-ENV USEGPU=${USEGPU}
+ENV USEGPU="false"
 
 ENV PYTHONDONTWRITEBYTECODE=true
 ENV PROC_HOME=/home/conda/back-projection
 ENV MYHOME=/home/conda
 
-RUN apt-get update && apt-get install -y --no-install-recommends unzip vim curl build-essential gfortran libfftw3-dev nvidia-driver-535 && \
+RUN apt-get update && apt-get install -y --no-install-recommends unzip vim curl build-essential gfortran libfftw3-dev && \
     apt-get clean && rm -rf /var/lib/apt/lists/*
 
 ARG CONDA_UID=1000
@@ -41,18 +40,9 @@ RUN groupadd -g "${CONDA_GID}" --system conda && \
 
 SHELL ["/bin/bash", "-l", "-c"]
 
-COPY ./scripts/install_cuda.sh ./
-RUN chmod +x ./install_cuda.sh
-RUN if [[ $USEGPU == "yes" ]] ; then ./install_cuda.sh ; else echo "Skipping CUDA install..." ; fi
-
 USER ${CONDA_UID}
 WORKDIR /home/conda/
 
-RUN if [[ $USEGPU == "true" ]] ; then \
-    echo "export PATH="/usr/local/cuda-12.4/bin:$PATH"" >> .bashrc && \
-    echo "export LD_LIBRARY_PATH="/usr/local/cuda-12.4/lib64:$LD_LIBRARY_PATH"" >> .bashrc \
-    ; else echo "Skipping exporting CUDA path." ; fi
-
 RUN curl -sL https://github.com/ASFHyP3/back-projection/archive/refs/tags/v${BACK_PROJECTION_TAG}.tar.gz > ./back-projection.tar.gz && \
     mkdir -p ./back-projection && \
     tar -xvf ./back-projection.tar.gz -C ./back-projection/ --strip=1 && \
diff --git a/Dockerfile.gpu b/Dockerfile.gpu
new file mode 100644
index 0000000..9066135
--- /dev/null
+++ b/Dockerfile.gpu
@@ -0,0 +1,86 @@
+FROM nvidia/cuda:12.4.1-devel-ubuntu20.04
+
+# For opencontainers label definitions, see:
+#    https://github.com/opencontainers/image-spec/blob/master/annotations.md
+LABEL org.opencontainers.image.title="HyP3 back-projection"
+LABEL org.opencontainers.image.description="HyP3 plugin for back-projection processing"
+LABEL org.opencontainers.image.vendor="Alaska Satellite Facility"
+LABEL org.opencontainers.image.authors="ASF Tools Team <UAF-asf-apd@alaska.edu>"
+LABEL org.opencontainers.image.licenses="BSD-3-Clause"
+LABEL org.opencontainers.image.url="https://github.com/ASFHyP3/hyp3-back-projection"
+LABEL org.opencontainers.image.source="https://github.com/ASFHyP3/hyp3-back-projection"
+LABEL org.opencontainers.image.documentation="https://hyp3-docs.asf.alaska.edu"
+
+ARG DEBIAN_FRONTEND=noninteractive
+ARG CONDA_UID=1000
+ARG CONDA_GID=1000
+ARG BACK_PROJECTION_TAG=0.2.0
+ARG FFTW_TAG=3.3.9
+ARG MINIFORGE_NAME=Miniforge3
+ARG MINIFORGE_VERSION=24.3.0-0
+
+# USEGPU environment variable used by build_proc.sh
+ENV USEGPU="true" 
+ENV CONDA_DIR=/opt/conda
+ENV LANG=C.UTF-8 LC_ALL=C.UTF-8
+ENV PATH=${CONDA_DIR}/bin:${PATH}
+ENV PYTHONDONTWRITEBYTECODE=true
+ENV PROC_HOME=/home/conda/back-projection
+ENV MYHOME=/home/conda
+
+# Conda setup
+RUN apt-get update > /dev/null && \
+    apt-get install --no-install-recommends --yes \
+        wget bzip2 ca-certificates \
+        git \
+        tini \
+        > /dev/null && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/* && \
+    wget --no-hsts --quiet https://github.com/conda-forge/miniforge/releases/download/${MINIFORGE_VERSION}/${MINIFORGE_NAME}-${MINIFORGE_VERSION}-Linux-$(uname -m).sh -O /tmp/miniforge.sh && \
+    /bin/bash /tmp/miniforge.sh -b -p ${CONDA_DIR} && \
+    rm /tmp/miniforge.sh && \
+    conda clean --tarballs --index-cache --packages --yes && \
+    find ${CONDA_DIR} -follow -type f -name '*.a' -delete && \
+    find ${CONDA_DIR} -follow -type f -name '*.pyc' -delete && \
+    conda clean --force-pkgs-dirs --all --yes  && \
+    echo ". ${CONDA_DIR}/etc/profile.d/conda.sh && conda activate base" >> /etc/skel/.bashrc && \
+    echo ". ${CONDA_DIR}/etc/profile.d/conda.sh && conda activate base" >> ~/.bashrc
+
+RUN apt-get update && apt-get install -y --no-install-recommends unzip vim curl build-essential gfortran libfftw3-dev && \
+    apt-get clean && rm -rf /var/lib/apt/lists/*
+
+RUN groupadd -g "${CONDA_GID}" --system conda && \
+    useradd -l -u "${CONDA_UID}" -g "${CONDA_GID}" --system -d /home/conda -m  -s /bin/bash conda && \
+    chown -R conda:conda /opt && \
+    echo ". /opt/conda/etc/profile.d/conda.sh" >> /home/conda/.profile && \
+    echo "conda activate base" >> /home/conda/.profile
+
+SHELL ["/bin/bash", "-l", "-c"]
+
+USER ${CONDA_UID}
+WORKDIR /home/conda/
+
+RUN curl -sL https://github.com/ASFHyP3/back-projection/archive/refs/tags/v${BACK_PROJECTION_TAG}.tar.gz > ./back-projection.tar.gz && \
+    mkdir -p ./back-projection && \
+    tar -xvf ./back-projection.tar.gz -C ./back-projection/ --strip=1 && \
+    rm ./back-projection.tar.gz && \
+    rm -rf ./back-projection/fft
+
+COPY --chown=${CONDA_UID}:${CONDA_GID} ./scripts/build_proc.sh ./back-projection
+RUN cd /home/conda/back-projection && \
+    chmod +x ./build_proc.sh && \
+    ./build_proc.sh && \
+    find $PROC_HOME -type f -name "*.py" -exec chmod +x {} + && \
+    cd /home/conda/
+
+COPY --chown=${CONDA_UID}:${CONDA_GID} . /hyp3-back-projection/
+
+RUN mamba env create -f /hyp3-back-projection/environment.yml && \
+    conda clean -afy && \
+    conda activate hyp3-back-projection && \
+    sed -i 's/conda activate base/conda activate hyp3-back-projection/g' /home/conda/.profile && \
+    python -m pip install --no-cache-dir /hyp3-back-projection
+
+ENTRYPOINT ["/hyp3-back-projection/src/hyp3_back_projection/etc/entrypoint.sh"]
+CMD ["-h"]
diff --git a/scripts/build_proc.sh b/scripts/build_proc.sh
index f3cfae1..08e080e 100644
--- a/scripts/build_proc.sh
+++ b/scripts/build_proc.sh
@@ -3,8 +3,10 @@
 MULTIARCH_DIR=/usr/lib/$(gcc -print-multiarch)
 FFTW_LIB=$MULTIARCH_DIR/libfftw3f.a
 echo 'using FFTW library:' $FFTW_LIB
+if [[ "$USEGPU" == "true" ]]; then
+    echo 'building with GPU support'
+fi
 
-# Works
 cd DEM
 gfortran -o mosaicDEM mosaicDEM.f90
 gfortran -o createspecialdem createspecialdem.f90
diff --git a/scripts/install_cuda.sh b/scripts/install_cuda.sh
deleted file mode 100644
index 2102f9e..0000000
--- a/scripts/install_cuda.sh
+++ /dev/null
@@ -1,11 +0,0 @@
-# Script to install nvidia drivers and the nvidia cuda toolkit.
-
-# Install Cuda Toolkit 12.4
-# Source: https://developer.nvidia.com/cuda-downloads?target_os=Linux&target_arch=x86_64&Distribution=Ubuntu&target_version=20.04&target_type=deb_local
-wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-ubuntu2004.pin && \
-mv cuda-ubuntu2004.pin /etc/apt/preferences.d/cuda-repository-pin-600 && \
-wget https://developer.download.nvidia.com/compute/cuda/12.4.1/local_installers/cuda-repo-ubuntu2004-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
-dpkg -i cuda-repo-ubuntu2004-12-4-local_12.4.1-550.54.15-1_amd64.deb && \
-cp /var/cuda-repo-ubuntu2004-12-4-local/cuda-*-keyring.gpg /usr/share/keyrings/ && \
-apt-get update && \
-apt-get -y install cuda-toolkit-12-4

From cf1033ccdd76eff53a4d639acbe56f5a9c30d6f6 Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Thu, 9 May 2024 15:37:19 -0500
Subject: [PATCH 14/23] swith to use of process_parallel for gpu case

---
 src/hyp3_back_projection/back_projection.py | 68 +++++++++++++++------
 src/hyp3_back_projection/utils.py           | 13 +++-
 tests/test_back_projection.py               |  4 +-
 3 files changed, 63 insertions(+), 22 deletions(-)

diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index 32a7119..4c9211f 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -30,28 +30,58 @@ def create_param_file(dem_path: Path, dem_rsc_path: Path, output_dir: Path):
         f.write('\n'.join(lines))
 
 
-def back_project_single_granule(granule_path: Path, orbit_path: Path, work_dir: Path, gpu: bool = False) -> None:
-    """Back-project a single Sentinel-1 level-0 granule.
-
-    Args:
-        granule_path: Path to the granule to back-project
-        orbit_path: Path to the orbit file for the granule
-        work_dir: Working directory for processing
-        gpu: Use the GPU-based version of the workflow, defaults to False
-    """
-    required_files = ['elevation.dem', 'elevation.dem.rsc', 'params']
+def check_required_files(required_files: Iterable, work_dir: Path) -> None:
     for file in required_files:
         if not (work_dir / file).exists():
             raise FileNotFoundError(f'Missing required file: {file}')
 
-    script = 'sentinel/sentinel_scene_multigpu.py' if gpu else 'sentinel/sentinel_scene_cpu.py'
-    args = [str(granule_path.with_suffix('')), str(orbit_path)]
-    utils.call_stanford_module(script, args, work_dir=work_dir)
+
+def clean_up_after_back_projection(work_dir: Path) -> None:
     patterns = ['*hgt*', 'dem*', 'DEM*', 'q*', '*positionburst*']
     for pattern in patterns:
         [f.unlink() for f in work_dir.glob(pattern)]
 
 
+def back_project_cpu(granule_orbit_pairs: Iterable, work_dir: Path) -> None:
+    """Back-project a set of Sentinel-1 level-0 granules using the CPU-based workflow.
+
+    Args:
+        granule_orbit_pairs: List of tuples of granule and orbit file paths
+        work_dir: Working directory for processing
+    """
+    check_required_files(['elevation.dem', 'elevation.dem.rsc', 'params'])
+
+    for granule_path, orbit_path in granule_orbit_pairs:
+        args = [str(granule_path.with_suffix('')), str(orbit_path)]
+        utils.call_stanford_module('sentinel/sentinel_scene_cpu.py', args, work_dir=work_dir)
+
+    clean_up_after_back_projection(work_dir)
+
+
+def create_zipped_safe_list(granule_paths: Iterable, work_dir: Path):
+    """Create a list of the zipped granules to process."""
+    with open(work_dir / 'ziplist', 'w') as f:
+        for granule_path in granule_paths:
+            f.write(f'{granule_path.name}\n')
+
+
+def back_project_gpu(granule_orbit_pairs: Iterable, work_dir: Path) -> None:
+    """Back-project a set of Sentinel-1 level-0 granules using the GPU-based workflow.
+
+    Args:
+        granule_orbit_pairs: List of tuples of granule and orbit file paths
+        work_dir: Working directory for processing
+    """
+    n_gpus = utils.how_many_gpus()
+    create_zipped_safe_list([x[0] for x in granule_orbit_pairs], work_dir)
+
+    check_required_files(['elevation.dem', 'elevation.dem.rsc', 'params', 'ziplist'])
+
+    utils.call_stanford_module('sentinel/process_parallel.py', ['ziplist', str(n_gpus)], work_dir=work_dir)
+
+    clean_up_after_back_projection(work_dir)
+
+
 def create_product(work_dir) -> Path:
     """Create a product zip file.
     Includes files needed for further processing (gslc, orbit, and parameter file).
@@ -113,19 +143,21 @@ def back_project(
 
     print('Downloading data...')
     bboxs = []
-    back_project_args = []
+    granule_orbit_pairs = []
     for granule in granules:
         granule_path, granule_bbox = utils.download_raw_granule(granule, work_dir)
         orbit_path = utils.download_orbit(granule, work_dir)
         bboxs.append(granule_bbox)
-        back_project_args.append((granule_path, orbit_path))
+        granule_orbit_pairs.append((granule_path, orbit_path))
 
     full_bbox = unary_union(bboxs).buffer(0.1)
     dem_path = dem.download_dem_for_back_projection(full_bbox, work_dir)
     create_param_file(dem_path, dem_path.with_suffix('.dem.rsc'), work_dir)
 
-    for granule_path, orbit_path in back_project_args:
-        back_project_single_granule(granule_path, orbit_path, work_dir=work_dir, gpu=gpu)
+    if gpu:
+        back_project_gpu(granule_orbit_pairs, work_dir=work_dir)
+    else:
+        back_project_cpu(granule_orbit_pairs, work_dir=work_dir)
 
     utils.call_stanford_module('util/merge_slcs.py', work_dir=work_dir)
 
@@ -133,7 +165,7 @@ def back_project(
         zip_path = create_product(work_dir)
         upload_file_to_s3(zip_path, bucket, bucket_prefix)
 
-    print(f'Finish back-projection for {list(work_dir.glob("S1*.geo"))[0].with_suffix("").name}!')
+    print(f'Finished back-projection for {list(work_dir.glob("S1*.geo"))[0].with_suffix("").name}!')
 
 
 def main():
diff --git a/src/hyp3_back_projection/utils.py b/src/hyp3_back_projection/utils.py
index 5408a57..74d6e0a 100644
--- a/src/hyp3_back_projection/utils.py
+++ b/src/hyp3_back_projection/utils.py
@@ -135,7 +135,7 @@ def get_earthdata_credentials() -> Tuple[str, str]:
     )
 
 
-def download_raw_granule(granule_name: str, output_dir: Path) -> Tuple[Path, Polygon]:
+def download_raw_granule(granule_name: str, output_dir: Path, unzip: bool = False) -> Tuple[Path, Polygon]:
     """Download a S1 granule using asf_search. Return its path
     and buffered extent.
 
@@ -160,7 +160,7 @@ def download_raw_granule(granule_name: str, output_dir: Path) -> Tuple[Path, Pol
     if not out_path.exists() and not zip_path.exists():
         result.download(path=output_dir, session=session)
 
-    if not out_path.exists():
+    if not out_path.exists() and unzip:
         with ZipFile(zip_path, 'r') as zip_ref:
             zip_ref.extractall('.')
 
@@ -201,3 +201,12 @@ def call_stanford_module(local_name, args: List = [], work_dir: Optional[Path] =
     args = [str(x) for x in args]
     print(f'Calling {local_name} {" ".join(args)} in directory {work_dir}')
     subprocess.run([script, *args], cwd=work_dir, check=True)
+
+
+def how_many_gpus():
+    """Get the number of GPUs available on the system using Stanford script."""
+    cmd = (get_proc_home() / 'sentinel' / 'howmanygpus').resolve()
+    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)
+    (param, err) = proc.communicate()
+    ngpus = int(str(param, 'UTF-8').split()[0])
+    return ngpus
diff --git a/tests/test_back_projection.py b/tests/test_back_projection.py
index e116242..4d5d608 100644
--- a/tests/test_back_projection.py
+++ b/tests/test_back_projection.py
@@ -24,7 +24,7 @@ def test_back_project_single_granule(tmp_path, monkeypatch):
     granule_path = tmp_path / 'granule.SAFE'
     orbit_path = tmp_path / 'orbit.xml'
     with pytest.raises(FileNotFoundError):
-        back_projection.back_project_single_granule(granule_path, orbit_path, tmp_path)
+        back_projection.back_project_cpu(granule_path, orbit_path, tmp_path)
 
     for f in ['elevation.dem', 'elevation.dem.rsc', 'params']:
         (tmp_path / f).touch()
@@ -35,7 +35,7 @@ def test_back_project_single_granule(tmp_path, monkeypatch):
     with monkeypatch.context() as m:
         mock_call_stanford_module = mock.Mock()
         m.setattr(utils, 'call_stanford_module', mock_call_stanford_module)
-        back_projection.back_project_single_granule(granule_path, orbit_path, tmp_path)
+        back_projection.back_project_cpu(granule_path, orbit_path, tmp_path)
         mock_call_stanford_module.assert_called_once_with(
             'sentinel/sentinel_scene_cpu.py',
             [str(granule_path.with_suffix('')), str(orbit_path)],

From 2725a0f63d6d131ca8468207e425083b8dab3820 Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Thu, 9 May 2024 15:43:26 -0500
Subject: [PATCH 15/23] fix unzip download option

---
 src/hyp3_back_projection/utils.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/hyp3_back_projection/utils.py b/src/hyp3_back_projection/utils.py
index 74d6e0a..6f45c50 100644
--- a/src/hyp3_back_projection/utils.py
+++ b/src/hyp3_back_projection/utils.py
@@ -155,16 +155,19 @@ def download_raw_granule(granule_name: str, output_dir: Path, unzip: bool = Fals
     bbox = shape(result.geojson()['geometry'])
 
     zip_path = output_dir / f'{granule_name[:-4]}.zip'
-    out_path = output_dir / f'{granule_name[:-4]}.SAFE'
+    if unzip:
+        out_path = zip_path
+    else:
+        out_path = output_dir / f'{granule_name[:-4]}.SAFE'
 
     if not out_path.exists() and not zip_path.exists():
         result.download(path=output_dir, session=session)
 
-    if not out_path.exists() and unzip:
+    if not out_path.exists():
         with ZipFile(zip_path, 'r') as zip_ref:
             zip_ref.extractall('.')
 
-    if zip_path.exists():
+    if zip_path.exists() and unzip:
         zip_path.unlink()
 
     return out_path, bbox

From a6f6cf9b74ffbecc5dfafbabfe3e8715da88093f Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Thu, 9 May 2024 16:11:57 -0500
Subject: [PATCH 16/23] fix small bugs

---
 src/hyp3_back_projection/back_projection.py |  7 ++++---
 src/hyp3_back_projection/utils.py           | 18 +++++++++---------
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index 4c9211f..48f19c0 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -49,7 +49,7 @@ def back_project_cpu(granule_orbit_pairs: Iterable, work_dir: Path) -> None:
         granule_orbit_pairs: List of tuples of granule and orbit file paths
         work_dir: Working directory for processing
     """
-    check_required_files(['elevation.dem', 'elevation.dem.rsc', 'params'])
+    check_required_files(['elevation.dem', 'elevation.dem.rsc', 'params'], work_dir)
 
     for granule_path, orbit_path in granule_orbit_pairs:
         args = [str(granule_path.with_suffix('')), str(orbit_path)]
@@ -73,7 +73,7 @@ def back_project_gpu(granule_orbit_pairs: Iterable, work_dir: Path) -> None:
         work_dir: Working directory for processing
     """
     n_gpus = utils.how_many_gpus()
-    create_zipped_safe_list([x[0] for x in granule_orbit_pairs], work_dir)
+    create_zipped_safe_list([x[0] for x in granule_orbit_pairs], work_dir=work_dir)
 
     check_required_files(['elevation.dem', 'elevation.dem.rsc', 'params', 'ziplist'])
 
@@ -145,7 +145,8 @@ def back_project(
     bboxs = []
     granule_orbit_pairs = []
     for granule in granules:
-        granule_path, granule_bbox = utils.download_raw_granule(granule, work_dir)
+        unzip = True if not gpu else False
+        granule_path, granule_bbox = utils.download_raw_granule(granule, work_dir, unzip)
         orbit_path = utils.download_orbit(granule, work_dir)
         bboxs.append(granule_bbox)
         granule_orbit_pairs.append((granule_path, orbit_path))
diff --git a/src/hyp3_back_projection/utils.py b/src/hyp3_back_projection/utils.py
index 6f45c50..85a5f7b 100644
--- a/src/hyp3_back_projection/utils.py
+++ b/src/hyp3_back_projection/utils.py
@@ -157,18 +157,18 @@ def download_raw_granule(granule_name: str, output_dir: Path, unzip: bool = Fals
     zip_path = output_dir / f'{granule_name[:-4]}.zip'
     if unzip:
         out_path = zip_path
+        result.download(path=output_dir, session=session)
     else:
         out_path = output_dir / f'{granule_name[:-4]}.SAFE'
+        if not out_path.exists() and not zip_path.exists():
+            result.download(path=output_dir, session=session)
 
-    if not out_path.exists() and not zip_path.exists():
-        result.download(path=output_dir, session=session)
-
-    if not out_path.exists():
-        with ZipFile(zip_path, 'r') as zip_ref:
-            zip_ref.extractall('.')
+        if not out_path.exists():
+            with ZipFile(zip_path, 'r') as zip_ref:
+                zip_ref.extractall('.')
 
-    if zip_path.exists() and unzip:
-        zip_path.unlink()
+        if zip_path.exists() and unzip:
+            zip_path.unlink()
 
     return out_path, bbox
 
@@ -209,7 +209,7 @@ def call_stanford_module(local_name, args: List = [], work_dir: Optional[Path] =
 def how_many_gpus():
     """Get the number of GPUs available on the system using Stanford script."""
     cmd = (get_proc_home() / 'sentinel' / 'howmanygpus').resolve()
-    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)
+    proc = subprocess.Popen(str(cmd), stdout=subprocess.PIPE, shell=True)
     (param, err) = proc.communicate()
     ngpus = int(str(param, 'UTF-8').split()[0])
     return ngpus

From e1518caa041a0231bb56bb6630a119e4d658349e Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Thu, 9 May 2024 16:26:56 -0500
Subject: [PATCH 17/23] swith back to using sentinel_scene_multigpu

---
 src/hyp3_back_projection/back_projection.py | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index 48f19c0..c2cb08a 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -4,6 +4,7 @@
 
 import argparse
 import logging
+import os
 import zipfile
 from pathlib import Path
 from typing import Iterable, Optional
@@ -42,7 +43,7 @@ def clean_up_after_back_projection(work_dir: Path) -> None:
         [f.unlink() for f in work_dir.glob(pattern)]
 
 
-def back_project_cpu(granule_orbit_pairs: Iterable, work_dir: Path) -> None:
+def back_project_granules(granule_orbit_pairs: Iterable, work_dir: Path, gpu: bool = False) -> None:
     """Back-project a set of Sentinel-1 level-0 granules using the CPU-based workflow.
 
     Args:
@@ -51,9 +52,14 @@ def back_project_cpu(granule_orbit_pairs: Iterable, work_dir: Path) -> None:
     """
     check_required_files(['elevation.dem', 'elevation.dem.rsc', 'params'], work_dir)
 
+    if gpu:
+        os.environ['CUDA_DEVICE_ORDER'] = 'PCI_BUS_ID'
+        os.environ['CUDA_VISIBLE_DEVICES'] = 1
+
+    cmd = 'sentinel/sentinel_scene_multigpu.py' if gpu else 'sentinel/sentinel_scene_cpu.py'
     for granule_path, orbit_path in granule_orbit_pairs:
         args = [str(granule_path.with_suffix('')), str(orbit_path)]
-        utils.call_stanford_module('sentinel/sentinel_scene_cpu.py', args, work_dir=work_dir)
+        utils.call_stanford_module(cmd, args, work_dir=work_dir)
 
     clean_up_after_back_projection(work_dir)
 
@@ -155,10 +161,7 @@ def back_project(
     dem_path = dem.download_dem_for_back_projection(full_bbox, work_dir)
     create_param_file(dem_path, dem_path.with_suffix('.dem.rsc'), work_dir)
 
-    if gpu:
-        back_project_gpu(granule_orbit_pairs, work_dir=work_dir)
-    else:
-        back_project_cpu(granule_orbit_pairs, work_dir=work_dir)
+    back_project_granules(granule_orbit_pairs, work_dir=work_dir, gpu=gpu)
 
     utils.call_stanford_module('util/merge_slcs.py', work_dir=work_dir)
 

From 3602d7d1c562916924c866f97df0cb39c28f3206 Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Thu, 9 May 2024 16:36:30 -0500
Subject: [PATCH 18/23] fix new bugs

---
 src/hyp3_back_projection/back_projection.py | 5 ++---
 src/hyp3_back_projection/utils.py           | 3 ++-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index c2cb08a..7c15558 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -54,7 +54,7 @@ def back_project_granules(granule_orbit_pairs: Iterable, work_dir: Path, gpu: bo
 
     if gpu:
         os.environ['CUDA_DEVICE_ORDER'] = 'PCI_BUS_ID'
-        os.environ['CUDA_VISIBLE_DEVICES'] = 1
+        os.environ['CUDA_VISIBLE_DEVICES'] = '1'
 
     cmd = 'sentinel/sentinel_scene_multigpu.py' if gpu else 'sentinel/sentinel_scene_cpu.py'
     for granule_path, orbit_path in granule_orbit_pairs:
@@ -151,8 +151,7 @@ def back_project(
     bboxs = []
     granule_orbit_pairs = []
     for granule in granules:
-        unzip = True if not gpu else False
-        granule_path, granule_bbox = utils.download_raw_granule(granule, work_dir, unzip)
+        granule_path, granule_bbox = utils.download_raw_granule(granule, work_dir, unzip=True)
         orbit_path = utils.download_orbit(granule, work_dir)
         bboxs.append(granule_bbox)
         granule_orbit_pairs.append((granule_path, orbit_path))
diff --git a/src/hyp3_back_projection/utils.py b/src/hyp3_back_projection/utils.py
index 85a5f7b..dc72bb2 100644
--- a/src/hyp3_back_projection/utils.py
+++ b/src/hyp3_back_projection/utils.py
@@ -157,7 +157,8 @@ def download_raw_granule(granule_name: str, output_dir: Path, unzip: bool = Fals
     zip_path = output_dir / f'{granule_name[:-4]}.zip'
     if unzip:
         out_path = zip_path
-        result.download(path=output_dir, session=session)
+        if not out_path.exists():
+            result.download(path=output_dir, session=session)
     else:
         out_path = output_dir / f'{granule_name[:-4]}.SAFE'
         if not out_path.exists() and not zip_path.exists():

From 661cc2a9be3cba6d1300fb3685a11045d67b8672 Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Mon, 13 May 2024 09:13:29 -0500
Subject: [PATCH 19/23] fix small bugs

---
 src/hyp3_back_projection/back_projection.py | 2 +-
 src/hyp3_back_projection/utils.py           | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index 7c15558..9d3585b 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -54,7 +54,7 @@ def back_project_granules(granule_orbit_pairs: Iterable, work_dir: Path, gpu: bo
 
     if gpu:
         os.environ['CUDA_DEVICE_ORDER'] = 'PCI_BUS_ID'
-        os.environ['CUDA_VISIBLE_DEVICES'] = '1'
+        os.environ['CUDA_VISIBLE_DEVICES'] = '0'
 
     cmd = 'sentinel/sentinel_scene_multigpu.py' if gpu else 'sentinel/sentinel_scene_cpu.py'
     for granule_path, orbit_path in granule_orbit_pairs:
diff --git a/src/hyp3_back_projection/utils.py b/src/hyp3_back_projection/utils.py
index dc72bb2..5994109 100644
--- a/src/hyp3_back_projection/utils.py
+++ b/src/hyp3_back_projection/utils.py
@@ -142,6 +142,7 @@ def download_raw_granule(granule_name: str, output_dir: Path, unzip: bool = Fals
     Args:
         granule_name: Name of the granule to download
         output_dir: Directory to save the granule in
+        unzip: Unzip the granule if it is a zip file
 
     Returns:
         Tuple of the granule path and its extent as a Polygon
@@ -155,7 +156,7 @@ def download_raw_granule(granule_name: str, output_dir: Path, unzip: bool = Fals
     bbox = shape(result.geojson()['geometry'])
 
     zip_path = output_dir / f'{granule_name[:-4]}.zip'
-    if unzip:
+    if not unzip:
         out_path = zip_path
         if not out_path.exists():
             result.download(path=output_dir, session=session)

From 131f30ce1dad6f12aac5191b9b0d9a5acdc5ad0c Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Mon, 13 May 2024 09:52:48 -0500
Subject: [PATCH 20/23] cleanup

---
 src/hyp3_back_projection/back_projection.py | 24 ---------------------
 tests/test_back_projection.py               |  6 +++---
 2 files changed, 3 insertions(+), 27 deletions(-)

diff --git a/src/hyp3_back_projection/back_projection.py b/src/hyp3_back_projection/back_projection.py
index 9d3585b..d702eef 100644
--- a/src/hyp3_back_projection/back_projection.py
+++ b/src/hyp3_back_projection/back_projection.py
@@ -64,30 +64,6 @@ def back_project_granules(granule_orbit_pairs: Iterable, work_dir: Path, gpu: bo
     clean_up_after_back_projection(work_dir)
 
 
-def create_zipped_safe_list(granule_paths: Iterable, work_dir: Path):
-    """Create a list of the zipped granules to process."""
-    with open(work_dir / 'ziplist', 'w') as f:
-        for granule_path in granule_paths:
-            f.write(f'{granule_path.name}\n')
-
-
-def back_project_gpu(granule_orbit_pairs: Iterable, work_dir: Path) -> None:
-    """Back-project a set of Sentinel-1 level-0 granules using the GPU-based workflow.
-
-    Args:
-        granule_orbit_pairs: List of tuples of granule and orbit file paths
-        work_dir: Working directory for processing
-    """
-    n_gpus = utils.how_many_gpus()
-    create_zipped_safe_list([x[0] for x in granule_orbit_pairs], work_dir=work_dir)
-
-    check_required_files(['elevation.dem', 'elevation.dem.rsc', 'params', 'ziplist'])
-
-    utils.call_stanford_module('sentinel/process_parallel.py', ['ziplist', str(n_gpus)], work_dir=work_dir)
-
-    clean_up_after_back_projection(work_dir)
-
-
 def create_product(work_dir) -> Path:
     """Create a product zip file.
     Includes files needed for further processing (gslc, orbit, and parameter file).
diff --git a/tests/test_back_projection.py b/tests/test_back_projection.py
index 4d5d608..05ee50d 100644
--- a/tests/test_back_projection.py
+++ b/tests/test_back_projection.py
@@ -20,11 +20,11 @@ def test_create_param_file(tmp_path):
     assert lines[1] == str(dem_rsc_path)
 
 
-def test_back_project_single_granule(tmp_path, monkeypatch):
+def test_back_project_granules(tmp_path, monkeypatch):
     granule_path = tmp_path / 'granule.SAFE'
     orbit_path = tmp_path / 'orbit.xml'
     with pytest.raises(FileNotFoundError):
-        back_projection.back_project_cpu(granule_path, orbit_path, tmp_path)
+        back_projection.back_project_granules([(granule_path, orbit_path)], tmp_path)
 
     for f in ['elevation.dem', 'elevation.dem.rsc', 'params']:
         (tmp_path / f).touch()
@@ -35,7 +35,7 @@ def test_back_project_single_granule(tmp_path, monkeypatch):
     with monkeypatch.context() as m:
         mock_call_stanford_module = mock.Mock()
         m.setattr(utils, 'call_stanford_module', mock_call_stanford_module)
-        back_projection.back_project_cpu(granule_path, orbit_path, tmp_path)
+        back_projection.back_project_granules([(granule_path, orbit_path)], tmp_path)
         mock_call_stanford_module.assert_called_once_with(
             'sentinel/sentinel_scene_cpu.py',
             [str(granule_path.with_suffix('')), str(orbit_path)],

From b6c9a11aebdbe8be63356ef22b494ec6f364c187 Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Mon, 13 May 2024 10:03:22 -0500
Subject: [PATCH 21/23] add ec2 instructions to readme

---
 README.md | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 874a4d1..dbbc171 100644
--- a/README.md
+++ b/README.md
@@ -55,4 +55,32 @@ before, check out this [guide](https://harmony.earthdata.nasa.gov/docs#getting-s
 ## GPU Setup:
 In order for Docker to be able to use the host's GPU, the host must have the [NVIDIA Container Toolkit](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/index.html) installed and configured. 
 The process is different for different OS's and Linux distros. The setup process for the most common distros, including Ubuntu, 
-can be found [here](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/install-guide.html#configuration). Make sure to follow the [Docker configuration steps](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/install-guide.html#configuration) after installing the package. **This process is not necessary when running in AWS while using an EC2 image made with GPU support.**
+can be found [here](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/install-guide.html#configuration). Make sure to follow the [Docker configuration steps](https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/latest/install-guide.html#configuration) after installing the package.
+
+### EC2 Setup
+When running on an EC2 instance, the following setup is recommended:
+1. Create a [P3-family EC2 instance](https://aws.amazon.com/ec2/instance-types/p3/) with the [Amazon Linux 2 AMI with NVIDIA TESLA GPU Driver](https://aws.amazon.com/marketplace/pp/prodview-64e4rx3h733ru?sr=0-4&ref_=beagle&applicationId=AWSMPContessa)
+1. Install Docker and the nvidia-container-toolkit on the EC2
+```bash
+sudo yum-config-manager --disable amzn2-graphics
+curl -s -L https://nvidia.github.io/libnvidia-container/stable/rpm/nvidia-container-toolkit.repo | sudo tee /etc/yum.repos.d/nvidia-container-toolkit.repo
+sudo yum install docker -y
+sudo yum install nvidia-container-toolkit -y
+sudo yum-config-manager --enable amzn2-graphics
+```
+1. Optionally, set up Docker to not require `sudo` and to start when the instance starts
+```bash
+sudo systemctl start docker && \
+sudo usermod -a -G docker ec2-user && \
+sudo systemctl enable docker
+```
+1. Exit the instance and re-enter
+1. To test the GPU setup, run the base NVIDIA container:
+```bash
+docker run -it --gpus all nvidia/cuda:12.4.1-devel-ubuntu20.04 nvidia-smi
+```
+1. Build the actual container and run it:
+```bash
+docker build -t back-projection:gpu -f Dockerfile.gpu .
+docker run --gpus=all --rm -it back-projection:gpu ++process back_projection --help
+```

From c22fa6c70265d3bae80dd079dac977825e8b5555 Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Mon, 13 May 2024 10:04:10 -0500
Subject: [PATCH 22/23] fix numbering

---
 README.md | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index dbbc171..83b61d9 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,7 @@ can be found [here](https://docs.nvidia.com/datacenter/cloud-native/container-to
 ### EC2 Setup
 When running on an EC2 instance, the following setup is recommended:
 1. Create a [P3-family EC2 instance](https://aws.amazon.com/ec2/instance-types/p3/) with the [Amazon Linux 2 AMI with NVIDIA TESLA GPU Driver](https://aws.amazon.com/marketplace/pp/prodview-64e4rx3h733ru?sr=0-4&ref_=beagle&applicationId=AWSMPContessa)
-1. Install Docker and the nvidia-container-toolkit on the EC2
+2. Install Docker and the nvidia-container-toolkit on the EC2
 ```bash
 sudo yum-config-manager --disable amzn2-graphics
 curl -s -L https://nvidia.github.io/libnvidia-container/stable/rpm/nvidia-container-toolkit.repo | sudo tee /etc/yum.repos.d/nvidia-container-toolkit.repo
@@ -68,18 +68,18 @@ sudo yum install docker -y
 sudo yum install nvidia-container-toolkit -y
 sudo yum-config-manager --enable amzn2-graphics
 ```
-1. Optionally, set up Docker to not require `sudo` and to start when the instance starts
+3. Optionally, set up Docker to not require `sudo` and to start when the instance starts
 ```bash
 sudo systemctl start docker && \
 sudo usermod -a -G docker ec2-user && \
 sudo systemctl enable docker
 ```
-1. Exit the instance and re-enter
-1. To test the GPU setup, run the base NVIDIA container:
+4. Exit the instance and re-enter
+5. To test the GPU setup, run the base NVIDIA container:
 ```bash
 docker run -it --gpus all nvidia/cuda:12.4.1-devel-ubuntu20.04 nvidia-smi
 ```
-1. Build the actual container and run it:
+6. Build the actual container and run it:
 ```bash
 docker build -t back-projection:gpu -f Dockerfile.gpu .
 docker run --gpus=all --rm -it back-projection:gpu ++process back_projection --help

From d75eca643468b70e2b6868c9cbea45c606f451c6 Mon Sep 17 00:00:00 2001
From: Forrest Williams <ffwilliams2@alaska.edu>
Date: Mon, 13 May 2024 10:05:24 -0500
Subject: [PATCH 23/23] add ec2 language

---
 README.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 83b61d9..933c3f2 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,7 @@ can be found [here](https://docs.nvidia.com/datacenter/cloud-native/container-to
 ### EC2 Setup
 When running on an EC2 instance, the following setup is recommended:
 1. Create a [P3-family EC2 instance](https://aws.amazon.com/ec2/instance-types/p3/) with the [Amazon Linux 2 AMI with NVIDIA TESLA GPU Driver](https://aws.amazon.com/marketplace/pp/prodview-64e4rx3h733ru?sr=0-4&ref_=beagle&applicationId=AWSMPContessa)
-2. Install Docker and the nvidia-container-toolkit on the EC2
+2. Install Docker and the nvidia-container-toolkit on the EC2 instance:
 ```bash
 sudo yum-config-manager --disable amzn2-graphics
 curl -s -L https://nvidia.github.io/libnvidia-container/stable/rpm/nvidia-container-toolkit.repo | sudo tee /etc/yum.repos.d/nvidia-container-toolkit.repo
@@ -68,13 +68,13 @@ sudo yum install docker -y
 sudo yum install nvidia-container-toolkit -y
 sudo yum-config-manager --enable amzn2-graphics
 ```
-3. Optionally, set up Docker to not require `sudo` and to start when the instance starts
+3. Optionally, set up Docker to not require `sudo` and to start when the EC2 instance starts
 ```bash
 sudo systemctl start docker && \
 sudo usermod -a -G docker ec2-user && \
 sudo systemctl enable docker
 ```
-4. Exit the instance and re-enter
+4. Exit the EC2 instance and re-enter
 5. To test the GPU setup, run the base NVIDIA container:
 ```bash
 docker run -it --gpus all nvidia/cuda:12.4.1-devel-ubuntu20.04 nvidia-smi