ATCOR 2 and ATCOR 3 for Satellite Remote Sensing Systems
Atmospheric & Topographic Correction for Small FOV Satellite Images
ATCOR 2 and 3 provide a full set of Features for the correction of standard satellite remote sensing systems as supported by ReSe. The methods are published in scientific literatures. Example Results for both ATCOR-2 and ATCOR3 are described in here.
The task of earth observing sensors is to map surface properties. However, the surface information is masked as the signal recorded by spaceborne optical sensors consists of several components and their magnitudes depend on atmospheric conditions, see Figure 1. In addition, topographic effects strongly influence the recorded signal. The objective of an atmospheric correction is to eliminate atmospheric and illumination effects to retrieve physical parameters of the earth's surface, e.g. surface reflectance, emissivity and temperature.
This information can be used for monitoring, change detection, surface-vegetation atmosphere transfer (SVAT) modeling, and surface energy balance investigations for climatic modeling and upscaling. Therefore, atmospheric correction is an essential part of preprocessing and a prerequisite for the derivation of certain value adding products.
The method is mainly intended for small field-of-view sensors where the angular dependence of atmospheric parameters can be neglected. However, some wide field-of-view sensors such as IRS-1C/1D WiFS are also supported.
More details on the processing (thermal bands, rugged terrain) can be found in the section "Method" for flat and mountainous terrain ).
As an additional option the following value adding products can be calculated: SAVI vegetation index, LAI, FPAR, albedo (wavelength-integrated reflectance 0.4-2.5 microns), and absorbed solar radiation flux. If the sensor has at least one thermal band and the boundary layer air temperature is specified then the following radiation and heat fluxes are included as additional output channels: difference between downwelling longwave thermal atmospheric flux and emitted surface flux, net radiation, ground heat flux, latent heat flux, sensible heat. All radiation and heat fluxes are given in Watts per square meter.
The original implementation of the ATCOR software was developed by Dr. Rudolf Richter at DLR (German Aerospace Center). It is licensed to ReSe Applications Schläpfer which takes care for the software maintenance, distribution, and marketing, and adds its own processing modules to the software package.