I wish to analyse several days' worth of Aerosol Optical Depth retrievals from (MYD04_L2) data over the Atlantic Ocean. I have limited experience of using GDAL, but only analysing a single MODIS tile at a time. I'm still relatively new to using remote sensing data.

Could anybody point me in the direction of how to visualise several MODIS tiles simultaneously on a map?

2 Answers 2


You can project to whatever you want using gdalwarp. I'm using two MOD04_L2 files here, but you could use however many you wanted and made sense (these two probably don't make sense as they are from different days, but whatever!)

gdalwarp -of GTIFF -tps -t_srs EPSG:4326 \
HDF4_EOS:EOS_SWATH:"MOD04_L2.A2020151.0950.061.2020151191628.hdf":mod04:Image_Optical_Depth_Land_And_Ocean \

The trick here is to use the tps option to do some interpolation of the swath locations to a regular grid.

If you wanted to reproject this to a different projection, spatial region, etc (this will tell GDAL to come up with its own box and spatial resolution), you can check the t_srs option (for the new projection), xRes and yRes for x and y spatial resolution and the te option to define the corner coordinates of interest.

You can also do this in Python directly:

import numpy as np
import matplotlib.pyplot as plt
import gdal

f_tmpl ='HDF4_EOS:EOS_SWATH:"%s":mod04:Image_Optical_Depth_Land_And_Ocean'
fnames = ["MOD04_L2.A2020151.0950.061.2020151191628.hdf",
ffs = [f_tmpl % f for f in fnames]
g = gdal.Warp("", ffs, format="MEM", 
              tps=True, dstSRS="EPSG:4326")
data = g.ReadAsArray()

If you are working with python, you should use the pymodis package http://www.pymodis.org to easily download, reproject and mosaic the data to the extent of your are of interest.

  • Not sure this is right, the MYD04_L2 is a swath product, not gridded, and I think pymodis only deals with gridded products.
    – Jose
    Commented Jun 12, 2020 at 20:43

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