diff --git a/modules/util/viirs_l1b_l2.py b/modules/util/viirs_l1b_l2.py
index eb51449440650f98ac20b7a3c88f5ee994142374..3946186573eb26c1c1bb6aca6155b568d8f2ca11 100644
--- a/modules/util/viirs_l1b_l2.py
+++ b/modules/util/viirs_l1b_l2.py
@@ -1,6 +1,6 @@
 import numpy as np
 import h5py
-from util.util import get_grid_values
+from util.util import get_grid_values, get_grid_values_all, is_night
 import glob
 import os
 from pathlib import Path
@@ -215,6 +215,20 @@ def run(data_h5f, label_h5f, data_tiles, label_tiles, mod_tile_width=64, border=
             label_tiles.append(nda)
 
 
+def scan(directory):
+    for p in os.scandir(directory):
+        if not p.is_dir():
+            continue
+        files = glob.glob(directory + p.name+'/'+'clavrx_snpp_viirs*.uwssec*.h5')
+
+        for idx, file in enumerate(files):
+            h5f = h5py.File(file, 'r')
+            solzen = get_grid_values_all(h5f, 'solar_zenith_angle')
+            if is_night(solzen):
+                print(file)
+            h5f.close()
+
+
 # def run_mean_std(directory):
 #
 #     data_dct = {name: [] for name in mod_res_params}