Adaptive radar detection in doubly nonstationary autoregressive doppler spread clutter
The problem of adaptive radar detection in clutter which is nonstationary both in slow and fast time is addressed. Nonstationarity within a coherent processing interval (CPI) often precludes target detection because of the masking induced by Doppler spreading of the clutter. Across range bins (i.e., fast time), nonstationarity severely limits the amount of training data available to estimate the noise covariance matrix required for adaptive detection. Such difficult clutter conditions are not uncommon in complex multipath propagation conditions where path lengths can change abruptly in dynamic scenarios. To mitigate nonstationary Doppler spread clutter, an approximation to the generalized likelihood ratio test (GLRT) detector is presented wherein the CPI from the hypothesized target range is used for both clutter estimation and target detection. To overcome the lack of training data, a modified time-varying autoregressive (TVAR) model is assumed for the clutter return. In particular, maximum likelihood (ML) estimates of the TVAR parameters, computed from a single snapshot of data, are used in a GLRT for detecting stationary targets in possibly abruptly nonstationary clutter. The GLRT is compared with three alternative methods including a conceptually simpler ad hoc approach based on extrapolation of quasi-stationary data segments. Detection performance is assessed using simulated targets in both synthetically-generated and real radar clutter. Results suggest the proposed GLRT with TVAR clutter modeling can provide between 58 dB improvement in signal-to-clutter plus noise ratio (SCNR) when compared with the conventional methods. © 2009 IEEE.
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Related Subject Headings
- Aerospace & Aeronautics
- 4009 Electronics, sensors and digital hardware
- 4006 Communications engineering
- 4001 Aerospace engineering
- 0909 Geomatic Engineering
- 0906 Electrical and Electronic Engineering
- 0901 Aerospace Engineering
Citation
Published In
DOI
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Aerospace & Aeronautics
- 4009 Electronics, sensors and digital hardware
- 4006 Communications engineering
- 4001 Aerospace engineering
- 0909 Geomatic Engineering
- 0906 Electrical and Electronic Engineering
- 0901 Aerospace Engineering