Method for reducing false alarm rate in radar images
First Claim
1. A method for reducing the false alarm rate produced by the number of alarms of fixed targets erroneously declared as moving targets in the radar images of two- or multi-channel MTI radar devices, comprising the steps of:
- providing and using a space time adaptive processing filter in a visible side antenna lobe in the radar image for the suppression of fixed targets in the side antenna lobe, comparing amplitude amounts or power values of range Doppler frequency cells with a threshold specified in constant terms and summing of resulting alarms from said comparison, wherein only those alarms whose amplitude amounts or power values are above the specified threshold are used and combined into clusters, wherein first a summary of alarms that is directed in a direction of the Doppler frequency into Doppler frequency clusters occurs based on their minimal distance to each other and subsequently a summary of Doppler frequency clusters that is directed in a distance direction into range Doppler frequency clusters occurs based on their minimal distance to each other, comparing a target function with a test function, wherein the test function is an intersecting function of a two-dimensional characteristic function of the amplitude and phase progressions of a main antenna lobe as a function of the Doppler frequency and the target function is a characteristic function, calculated for each alarm, of the amplitude and phase progressions of a respective target as a function of the Doppler frequency on the Doppler frequency position of the respective target, and determining selection criteria from suitable combined calculation methods that are applied to the test and target functions for the purpose of classifying a respective target alarm as a moving or fixed target alarm.
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Abstract
A method for reducing the false alarm rate, i.e. the number of alarms of fixed targets erroneously declared as moving targets in the radar images of two- or multi-channel MTI radar devices, wherein the suppression of fixed target echoes over the moving target echoes within the main antenna lobe occurs through a space time adaptive processing—STAP—filter. The method uses a comparison of the amplitude amounts or power values of the range Doppler frequency cells with a threshold that can be specified in constant terms and summary of the resulting alarms. A target function is compared with defined test functions and selection criteria are determined from suitable combined calculation methods that are applied to the test and target functions for the purpose of classifying a respective target alarm as a moving or fixed target alarm.
16 Citations
10 Claims
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1. A method for reducing the false alarm rate produced by the number of alarms of fixed targets erroneously declared as moving targets in the radar images of two- or multi-channel MTI radar devices, comprising the steps of:
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providing and using a space time adaptive processing filter in a visible side antenna lobe in the radar image for the suppression of fixed targets in the side antenna lobe, comparing amplitude amounts or power values of range Doppler frequency cells with a threshold specified in constant terms and summing of resulting alarms from said comparison, wherein only those alarms whose amplitude amounts or power values are above the specified threshold are used and combined into clusters, wherein first a summary of alarms that is directed in a direction of the Doppler frequency into Doppler frequency clusters occurs based on their minimal distance to each other and subsequently a summary of Doppler frequency clusters that is directed in a distance direction into range Doppler frequency clusters occurs based on their minimal distance to each other, comparing a target function with a test function, wherein the test function is an intersecting function of a two-dimensional characteristic function of the amplitude and phase progressions of a main antenna lobe as a function of the Doppler frequency and the target function is a characteristic function, calculated for each alarm, of the amplitude and phase progressions of a respective target as a function of the Doppler frequency on the Doppler frequency position of the respective target, and determining selection criteria from suitable combined calculation methods that are applied to the test and target functions for the purpose of classifying a respective target alarm as a moving or fixed target alarm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for reducing a false alarm rate in a system for detecting moving targets from radar images, comprising the steps of:
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analyzing a visible side antenna lobe in a radar image by a time adaptive processing filter in order to suppress fixed targets in the side antenna lobe;
comparing values of range Doppler frequency cell with a specified threshold value;
providing an indication of alarms resulting from said step of comparing and summing said indicated alarms;
providing a summary of alarms directed in a direction of the Doppler frequency and providing Doppler frequency clusters based on their minimal distance to each other;
providing a summary of Doppler frequency clusters directed in a distance direction based on their minimal distance to each other;
comparing a target function with a test function, wherein said test function is an intersecting function of a 2-dimensional characteristic function of amplitude and phase progressions of a main antenna lobe as a function of the Doppler frequency and wherein the target function is a characteristic function, calculated for each alarm, of the amplitude and phase progressions of a respective target as a function of the Doppler frequency on the Doppler frequency position of the respective target; and
determining selection criteria from a suitable combined calculation method applied to the test and target functions in order to classify respective target alarms as a moving or fixed target alarm
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Specification