From f1604d436392c87448aa4a133a57b39c9bbe6e3b Mon Sep 17 00:00:00 2001
From: Zachary Hoppinen <56941602+ZachHoppinen@users.noreply.github.com>
Date: Thu, 7 Sep 2023 17:49:15 -0600
Subject: [PATCH] Update retrieval.py

---
 spicy_snow/retrieval.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/spicy_snow/retrieval.py b/spicy_snow/retrieval.py
index d3166a2..c0f8023 100644
--- a/spicy_snow/retrieval.py
+++ b/spicy_snow/retrieval.py
@@ -106,6 +106,9 @@ def retrieve_snow_depth(area: shapely.geometry.Polygon,
     search_results = s1_img_search(area, dates)
     log.info(f'Found {len(search_results)} results')
 
+    assert len(search_results) > 3, f"Need at least 4 images to run. Found {len(search_results)} \
+    using area: {area} and dates: {dates}."
+
     # download s1 images into dataset ['s1'] variable name
     jobs = hyp3_pipeline(search_results, job_name = job_name, existing_job_name = existing_job_name)
     imgs = download_hyp3(jobs, area, outdir = join(work_dir, 'tmp'), clean = False)