| Title | Effects of spectral, spatial, and radiometric characteristics on remote sensing vegetation indices of forested regions |
| Download | Downloads
(Preprint) |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Teillet, P M; Staenz, K; William, D J |
| Source | Remote Sensing of Environment 61, 1, 1997 p. 139-149, https://doi.org/10.1016/S0034-4257(96)00248-9 |
| Year | 1997 |
| Alt Series | Earth Sciences Sector, Contribution Series 20041558 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Released | 1997 07 01 |
| Abstract | Vegetation indices derived from satellite image data have become one of the primary information sources for monitoring vegetation conditions and mapping land cover change. The most widely used
vegetation index in this context is NDVI, the Normalized Difference Vegetation Index, which is a function of red and near-infrared spectral bands. Given that the spectral and spatial characteristics of imagery in the red and near-infrared vary from
sensor to sensor, NDVI values based on data from different instruments will not be directly comparable. The present study demonstrates the impact of changes in spectral bandwidth and spatial scale on NDVI derived from Airborne Visible/Infrared
Imaging Spectrometer (AVIRIS) data acquired at 20-m resolution over a forested region in Southeastern British Columbia. For this purpose, the 10-nm AVIRIS data were spectrally and spatially aggregated in the red and near-infrared to simulate
bandwidths from 10 nm to 150 nm for ground resolutions varying from 20 m to 1100 m. Sensor-specific spectral bands and spatial resolutions such as those for SPOT HRV, Landsat TM, NOAA AVHRR, EOS MODIS and Envisat MERIS were also generated. NDVI
values were then calculated using atmospherically corrected surface reflectances for forestry-related targets for the entire simulated band set at the various scales. The results indicate that the NDVI is significantly affected by differences in
spectral bandwidth, especially for the red band, and that changes in spatial resolution lead to less pervasive but more land cover specific effects on NDVI. Results also indicate that NDVI is not very sensitive to the location of the near-infrared
spectral band, provided that the bandwidth is no wider than 50 nm and the atmospheric correction for water vapour absorption is adequate. If either proviso is relaxed, the wavelength placement of the near-infrared spectral band is more critical, the
optimum location being in the 850 to 880 nm range. Finally, some results were also generated for several other vegetation indices that make straightforward use of atmospherically corrected red and near-infrared spectral bands. |
| GEOSCAN ID | 218360 |
|
|