The information below describes how the “Navigation Mode” output from a radar is derived from the radar’s view of the environment surrounding it.
This mode is a very simple approach to extracting features from the scene that the radar presents; it is ideally suited to extract features linked to solid, well-reflecting objects within the view of radar that do not have the COSEC² fill-in feature to the radar output beam.
The key parameters to configure the operation of this feature extraction process can be configured in a radar by Colossus message type 205 and the navigation mode output from the radar can be requested by Colossus message type 120. When this feature extraction method is appropriate, the network bandwidth utilisation for the radar’s connection is greatly reduced.
Alternatively, the source code for navigation mode feature extraction function is provided for both C++ and Python environments. This approach can be used to process the raw radar data within a customer’s complete control, and dynamic adjustment/adaptation of the key parameters is possible.
A much more robust, but computationally more intensive feature extraction method is CFAR - a “common form of adaptive algorithm used in radar systems to detect target returns against a background of noise, clutter and interference” (ISBN 0-201-19038-9).
There are various implementations of CFAR, and this approach to feature extraction is much more capable in high clutter environments, or radar scenes where a fixed thresholding approach across all ranges and azimuths is inappropriate.
