See the complete article: Publicly available global environmental layers
- Edited by: T. Hengl
MODIS data products
NASA's MODIS Earth observation system is one of the richest sources of remote-sensing data for monitoring of environmental dynamics (Huete et al. 2002; Friedl et al. 2010). Raw MODIS data stream can be received in real-time using a tracking antenna, while the scientific data (MODIS products) are available through various websites sites and FTP archives. The MODIS instruments captures data in 36 spectral bands ranging in wavelength from 0.4 µm to 14.4 µm and at three spatial resolutions (2 bands at 250 m, 5 bands at 500 m and 29 bands at 1 km). From the raw spectral data, numerous RS products have been derived. MODIS images are typically distributed as HDF (Hierarchical Data Format) 10 by 10 arcdegree-tiles, projected in the Sinusoidal projection (Chang Seong et al., 2002).
Some standard MODIS data products are (sorted per theme):
- MOD 01 - Level-1A Radiance Counts
- MOD 02 - Level-1B Calibrated Geolocated Radiances
- MOD 03 - Geolocation Data Set
- MOD 04 - Aerosol Product
- MOD 05 - Total Precipitable Water (Water Vapor)
- MOD 06 - Cloud Product
- MOD 07 - Atmospheric Profiles
- MOD 08 - Gridded Atmospheric Product
- MOD 35 - Cloud Mask
- MOD 09 - Surface Reflectance
- MOD 11 - Land Surface Temperature & Emissivity
- MOD 12 - Land Cover/Land Cover Change
- MOD 13 - Gridded Vegetation Indices (Max NDVI & Integrated MVI)
- MOD 14 - Thermail Anomalies, Fires & Biomass Burning
- MOD 15 - Leaf Area Index & FPAR
- MOD 16 - Evapotranspiration
- MOD 17 - Net Photosynthesis and Primary Productivity
- MOD 43 - Surface Reflectance
- MOD 44 - Vegetation Cover Conversion
- MOD 10 - Snow Cover
- MOD 29 - Sea Ice Cover
The European version of MODIS TERRA is the ENVISAT MERIS. The ENVISAT satellite is a platform for several instruments adjusted for monitoring of the environmental resources: ASAR, MERIS, AATSR, MWR and similar. The MEdium Resolution Image Spectrometer (MERIS) is used to obtain images of the Earth’s surface at temporal resolution of 3–days. The images comprise of 15 bands, all at resolution of 300 m. To obtain MERIS images, one needs to register and receive an access to the repository (unlike the MODIS images that are available directly via an FTP).
Obtaining MODIS data
MODIS images can be obtained from various websites. A stable source of MODIS images are the NASA's LAADS Web and ECHO Reverb. To obtain the HDF files connect to LAADS underlying FTP server. To convert HDF granules to some more usable GIS format, consider either using the MODIS resampling tool or GDAL utilities.
- Chang Seong, J., Mulcahy, K.A., Usery, E.L., 2002. The Sinusoidal Projection: A New Importance in Relation to Global Image Data. The Professional Geographer 54(2): 218-225.
- Friedl, M. A., D. Sulla-Menashe, B. Tan, A. Schneider, N. Ramankutty, A. Sibley, and X. Huang, 2010. MODIS Collection 5 global land cover: Algorithm refinements and characterization of new datasets. Remote Sens. Environ., 114(1), 168–182.
- Huete, A., Didan, K., Miura, T., Rodriguez, E.P., Gao, X., Ferreira, L.G., 2002. Overview of the radiometric and biophysical performance of the MODIS vegetation indices. Remote Sensing of Environment, 83: 195–213.