|
||||||
|
|
||||||
AVHRR Data at NSIDC |
The Advanced Very High Resolution Radiometer is used for a wide range of applications in polar and climate research. NSIDC uses AVHRR data because they provide a global, long-term, consistent time series with high spectral and spatial resolution suitable for albedo and surface temperature measurements. These types of measurements are necessary for studies involving climate, sea ice distribution and movement, and ice sheet coastal configuration.
The AVHRR sensor on the NOAA satellite series was originally designed for use as an imaging radiometer for meteorological purposes, rather than for quantitative radiometric sensing. However, as new applications evolved, quantitative radiometric data became necessary. The visible channels (1 and 2) provide direct quasi-linear conversion between the 10-bit digital numbers and reflectance. The thermal channels (3, 4, and 5) were designed to provide a conversion between the digital numbers and the temperature in degrees Celsius (or Kelvin). The primary reason for the introduction of the five-channel system was the need for atmospheric correction calculations in determining sea surface temperature.
The United States Geological Survey (USGS) describes the AVHRR instrument in its Advanced Very High Resolution Radiometer document.
