Conventional fixed threshold detectors set a fixed threshold based on the overall
statistical characteristics of the spatially uniform clutter over all ranges to give a
specific probability of false alarm and detection. However, in radar applications
clutter statistics are not known a priori. Constant False Alarm Rate (CFAR)
techniques provide an adaptive threshold to estimate the clutter statistics and to
distinguish targets from clutter. In Cell Averaging CFAR (CA-CFAR) the
threshold is controlled by averaging the fixed size CFAR cells surrounding the cell
under test.
In this thesis, radar detection of targets in sea clutter modelled by compound Kdistribution
is examined from a statistical detection viewpoint by Monte Carlo
simulations. The performance of CA-CFAR processors is analysed under varying
conditions of sea clutter spatial correlation and spikiness for several cases of false
alarm probability, the length of cell size used in the CFAR processor and the
number of pulses integrated prior to CA-CFAR processor.
v
The detection performance of CA-CFAR is compared with the performance of
fixed threshold detection. The performance evaluations are quantified by CFAR
loss. CFAR loss is defined as the increase in average signal to clutter ratio
compared to that of fixed threshold, required to achieve a given probability of
detection and probability of false alarm. Curves for CFAR loss to the spikiness and
spatial correlation of clutter, number of pulses integrated and the length of cell size
are presented.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12609857/index.pdf |
| Date | 01 February 2008 |
| Creators | Cetin, Aysin |
| Contributors | Hizal, Altunkan |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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