Radars are used for various purposes, and we need flexible methods to explain radar response phenomena. In general,
modeling radar response and backscatterers can help in data analysis by providing possible explanations for
measured echoes. However, extracting exact physical parameters of a real world scene from radar measurements
is an ill-posed problem.
Our study aims to enhance radar signal interpretation and further to develop data classification methods. In
this paper, we introduce an approach for finding physically sensible explanations for response phenomena during
a long illumination. The proposed procedure uses our comprehensive response model to decompose measured
radar echoes. The model incorporates both a radar model and a backscatterer model. The procedure adapts
the backscatterer model parameters to catch and reproduce a measured Doppler spectrum and its dynamics at a
particular range and angle. A filter bank and a set of features are used to characterize these response properties.
The procedure defines a number of point-scatterers for each frequency band of the measured Doppler spectrum.
Using the same features calculated from simulated response, it then matches the parameters-the number of
individual backscatterers, their radar cross sections and velocities-to joint Doppler and amplitude behavior of the
measurement. Hence we decompose the response toward its origin. The procedure is scalable and can be applied
to adapt the model to various other features as well, even those of more complex backscatterers. Performance
of the procedure is demonstrated with radar measurements on controlled arrangement of backscatterers with a
variety of motion states.
Geographical information systems (GIS) have been the base for radar ground echo simulations for many years.
Along with digital elevation model (DEM), present GIS contain characteristics of terrain. This paper proposes
a computationally sensible simulation procedure to produce realistic radar terrain signatures in a form of raw
data of airborne pulse Doppler radar. For backscattering simulation, the model of the ground is based on DEM
and built with point-form backscattering objects. In addition to the usual DEM utilization for xyz coordinates
and shadowed region calculation, we assume that each data point in GIS describes several scatterers in reality.
Approaching the ground truth, we distribute individual scatterers with adjustable attributes to produce authentic
response of areas such as sea, fields, forests, and built-up areas. This paper illustrates the approach through an
airborne side-looking synthetic aperture radar (SAR) simulation. The results prove the enhanced fidelity with
realistic SAR image features.