NDVI from Other Sensors

Science Center Objects

Readily available, no-charge data gathered by Landsat 7's Enhanced Thematic Mapper Plus (ETM+) sensor can also be used to generate NDVI image products (see Table 1). With a resolution of 30 m, ETM+ data can be transformed into NDVI images that have greater spatial detail than those derived from AVHRR, but which cover a smaller area. Furthermore, Landsat's orbit repeats every 16 days, compared to AVHRR's daily coverage. This makes creating cloud-free NDVI products from ETM+ data more challenging.

9 October 2001 MODIS image of New England

Fall foliage colors are visible in this 9 October 2001 MODIS image of New England.   Photo courtesy of NASA's Earth Observatory.

(Public domain.)

Another modern, well-calibrated, daily, moderate-resolution satellite sensor with the proper instrumentation for studying vegetation greenness is the Moderate Resolution Imaging Spectroradiometer (MODIS) carried aboard National Aeronautics and Space Administration (NASA) Terra and Aqua satellites. Global MODIS data are also readily available for no charge, and are high-quality input for vegetation time-series analysis. MODIS data are routinely transformed into vegetation index, NDVI, and enhanced vegetation index (EVI) image products with 250-m, 500-m, and 1-km spatial resolution.