Are you interested in imagery that covers our planet to study regional land and water cycles? Or perhaps you are interested in tracking agricultural development in the Midwest? Or in seeing changes in our landscape over time? If so, the Moderate Resolution Imaging Spectroradiometer (MODIS) is a sensor you need to check out.
With a footprint that is 2,330-kilometers (km) wide, the MODIS satellites are able to image the entire Earth every two days (and some locations are even covered daily). MODIS Terra was launched on December 18, 1999 and collects imagery at approximately 10:30AM over the Equator. MODIS Aqua was launched May 4, 2002 and collects imagery at approximately 1:30PM over the Equator.
Both MODIS satellites feature 36 spectral bands with resolutions ranging from 250 to 1,000 meters (m). MODIS collects data with 12-bit depth and the images can be downloaded from the easy-to-use USGS EarthExplorer. When you are searching for MODIS imagery, most will want to look for options under the Data Sets Tab and then NASA LPDAAC Collections –> MODIS Land Surface Reflectance. These are the most common MODIS products I have worked with:
- MOD09GQ – Terra Surface Reflectance Bands 1-2, 250-m, daily coverage
- MYD09GQ – Aqua Surface Reflectance Bands 1-2, 250-m, daily coverage
- MOD09GA – Terra Surface Reflectance Bands 1-7, 500/1000-m, daily coverage
- MYD09GA – Aqua Surface Reflectance Bands 1-7, 500/1000-m, daily coverage
The swirls on the ocean’s surface are the first formations of a sea ice sheet which will continue to develop as winter deepens in the Northern Hemisphere.
If you are interested in checking out some more amazing views of our planet, here is a link to the MODIS Images of the Day gallery.
Until my next edition of Free For All, happy hunting for free GIS data!
Brock Adam McCarty
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