SAR Processing

ENVI SARscape includes a set of processing tools to help you transform raw SAR data into an easy-to-interpret image for further analysis. ENVI SARscape processing tools are designed to work with a single image or a time series of images. This puts the data in an image format that allows you to derive useful information from it, such as extracting features of interest like buildings, or examining crop growth over a growing season.

Filtering Reduce speckle, while preserving radar reflectivity, textural properties and spatial resolution, especially in strongly textured SAR images with ENVI SARscape filters. These filters are particularly effective with polarimetric data. Includes SAR specific filters with algorithms based on Gamma/Gaussian-distributed scene models. Focusing In the rare case that you have specific raw data that requires focusing, ENVI SARscape supports the focusing of the following data: ERS-1/2 SAR, JERS-1 SAR, ENVISAT ASAR (including Wide Swath developed by Aresys), and ALOS PALSAR-1.

Multilooking Generate a multilooked image from Single Look Complex (SLC) data. This step squares up the pixels so that the data begins to look like a typical image. Geocoding Transform radar coordinates (from either ground or slant range) into a given cartographic reference system using a rigorous range-Doppler approach for ellipsoidal or terrain geocoding, using nominal parameters or Ground Control Points. The radiometric calibration, which is performed during the geocoding, is based on the exploitation of the radar equation. In addition, the radiometric normalization empirically corrects the effects of the incidence angle on sigma nought by applying a modified cosine correction.

Mosaicking Effortlessly combine SAR images (amplitude and/or coherence) or products (classification results) to obtain an entire coverage of the area with this automated workflow. When mapping large areas using SAR data, individual image frames are seamlessly joined together to create a consistent mosaic across the region. This method refines the radiometric variations by comparing the images to be mosaicked in the overlapping areas. Coregistration Make pixel-by-pixel comparisons of a time series of data sets of the same region, using automatic coregistration functionality in ENVI SARscape. In cases where pixel sizes vary, spatial registration, and resampling is also done automatically with the coregistration workflow.