Low Altitude Radar Wave Propagation Modelling

A robust technique for the prediction of field
strengths over irregular terrain profiles must be
polarization and frequency dependent, and must take
electrical properties, and details of the terrain
profile into account. An efficient method (RADCAL)
has been presented to model groundwave propagation
over irregular terrain in the presence of
range-dependent nonstandard environmental conditions.
The results from this model were compared against
measured data and other existing models and were
shown to give predominantly excellent agreement. The
final objective in model development is to produce a
real-time capability for predicting signal levels for
operational assessment, whether it be for military or
civilian requirements. We have presented a ray optics
based method to estimate the path propagation factor
of an irregular terrain. Explicit expressions are
obtained for the Divergence and Convergence factors
for the convex and concave spherically shaped slant
plateaus joining the hills and depression. The
algorithm developed is very fast and provides good
estimates of the propagation factor. Numerical
predictions are compared with other full wave and GO
methods and also measurements.