Exploitation of Long Coherent Integration Times to Improve Drone Detection in DVB-S based Passive Radar

Long time coherent integration is a vital method for improving the detection ability of global navigation satellite system (GNSS)-based passive radar, because the GNSS signal is not radar-designed and its power level is very low. For aircraft detection, the large range cell migration (RCM) and Doppler frequency migration (DFM) will seriously affect the coherent processing of azimuth signals, and the traditional range match filter will also be mismatched due to the Doppler-intolerant characteristic of GNSS signals. Accordingly, the energy loss of 2-dimensional (2-D) coherent processing is inevitable in traditional methods. In this paper, a novel 2-D coherent integration processing and algorithm for aircraft target detection is proposed. For azimuth processing, a modified Radon Fourier Transform (RFT) with range-walk removal and Doppler rate estimation is performed. In respect to range compression, a modified matched filter with a shifting Doppler is applied. As a result, the signal will be accurately focused in the range-Doppler domain, and a sufficiently high SNR can be obtained for aircraft detection with a moving target detector. Numerical simulations demonstrate that the range-Doppler parameters of an aircraft target can be obtained, and the position and velocity of the aircraft can be estimated accurately by multiple observation geometries due to abundant GNSS resources. The experimental results also illustrate that the blind Doppler sidelobe is suppressed effectively and the proposed algorithm has a good performance even in the presence of Doppler ambiguity.

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Coherent Integration Implementation for China Mobile Multimedia Broadcasting Based Passive Radar with Nonuniform Sampling

JOURNAL OF ELECTRONICS INFORMATION TECHNOLOGY ◽

10.3724/sp.j.1146.2012.00540 ◽

2013 ◽

Vol 34 (11) ◽

pp. 2648-2653 ◽

Cited By ~ 1

Author(s):

Jian-xin Yi ◽

Xian-rong Wan ◽

Liang Fang ◽

Bo Cen ◽

Yun-hua Rao

Keyword(s):

Nonuniform Sampling ◽

Mobile Multimedia ◽

Passive Radar ◽

Coherent Integration

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Effects of Movement for High Time-Bandwidths in Batched Pulse Compression Range-Doppler Radar

Sensors ◽

10.3390/s21072492 ◽

2021 ◽

Vol 21 (7) ◽

pp. 2492

Author(s):

Dominik Bok ◽

Daniel O’Hagan ◽

Peter Knott

Keyword(s):

Fast Moving ◽

Pulse Compression ◽

Doppler Radar ◽

Doppler Frequency ◽

Passive Radar ◽

Moving Targets ◽

Effective Velocity ◽

Coherent Integration ◽

The Impact ◽

Integration Gain

Radar detection and track building performance is an essential part of a radar system. A high realized coherent integration gain often contributes to an improved performance. This is essential to the successful detection and tracking of weak moving targets. However, the actual movement within the coherent processing interval can introduce range walk effects. The processing will then result in range and Doppler frequency resolutions that become finer than a single moving point scatterer’s spread over range and—often not considered—over Doppler frequency. In particular for a wide instantaneous bandwidth, the impact on the achievable integration gain can become severe already for a constant effective velocity. Therefore, high desired integration gains as required in passive radar are not easily achieved against relatively fast moving targets. The main intent of this article is to present the movement effects on a classical range-Doppler analysis to give an insight on the achievable performance and to quantify otherwise appearing degradations. Interestingly, a classical analysis of experimental datasets evaluated from a DVB-T based passive radar measurement campaign even resolved the fluctuation of a target response within the instantaneously processed bandwidth. The findings strengthen the need for advanced processing methods that can at least partly address individual implications of fast moving targets in real-time applications properly.

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