PRACTICAL ISSUES FOR RADAR TRACKING TRACK INITIATION AND CLUTTER REJECTION The problems of clutter rejection and track initiation are very much interwined. It is possible to use track initiation to help in the rejection of clutter. On the other hand it is possible to use appropriate clutter rejection techniques to reduce the track initiation load. Examples of these are discussed in the following sections. Use of Track Initiation to Eliminate Clutter The radar track initiator can be used to eliminate clutter by passing the clutter returns as well as target returns, which are indistinguishable initially, into the track initiation. | Tracking and Kalman Filtering Made Easy. Eli Brookner Copyright 1998 John Wiley Sons Inc. ISBNs 0-471-18407-1 Hardback 0-471-22419-7 Electronic 3 PRACTICAL ISSUES FOR RADAR TRACKING TRACK INITIATION AND CLUTTER REJECTION The problems of clutter rejection and track initiation are very much interwined. It is possible to use track initiation to help in the rejection of clutter. On the other hand it is possible to use appropriate clutter rejection techniques to reduce the track initiation load. Examples of these are discussed in the following sections. Use of Track Initiation to Eliminate Clutter The radar track initiator can be used to eliminate clutter by passing the clutter returns as well as target returns which are indistinguishable initially into the track initiation filter. However only those returns that behave like a moving target would be passed into track at the output of the track initiation filter thus finally eliminating the clutter returns. For example the stationary clutter returns would be dropped by the track initiation filter or classified as clutter returns for association with future such returns . The use of this approach can in some cases potentially provide about an order of magnitude or more increase in system sensitivity. This is the case when dealing with spiky clutter. In order to achieve a low false-alarm probability due to spiky clutter returns at the input to the track initiation filter it is necessary that the detector threshold be increased by 10 dB or more above what would be required if the clutter were not spiky that is if the clutter were Rayleigh distributed at the output of the receiver envelope detector which implies that it has a Gaussian distribution at the input to the envelope detector . This is shown to be the case in Figure for spiky sea clutter rain clutter lognormal 111 112 PRACTICAL ISSUES FOR RADAR TRACKING Figure Typical measured and theoretical clutter probability distributions. After Prengaman .
