A New Airborne Passive DF Method only Based on Frequency Difference

Abstract:

If three antenna units are divided into two set and two baselines are placed at right angles to each other in flight plain, in which the direction of one baseline is parallel to the actual flight direction of air vehicle, the sine and cosine function of target bearing respectively in two baseline directions can be simultaneously obtained according to the analysis principle of the direction cosine change rate. The angulations’ formula only based on Doppler frequency difference can be derived after eliminating the unknown parameters including angular velocity and wavelength by the specific value of two circular functions. The analog calculation shows that the relative error is in direct proportion to the baseline length provided that the incident wave is parallel in derivation. But the error analysis depicts that the measurement accuracy is in direct proportion to the baseline length. Moreover, the measurement error relies on mainly the accuracy of frequency measurement. Furthermore, the derived formula has irregularity in airborne axis direction. However, since the new method is not associated with wavelength, this new DF only based on Doppler frequency difference will be more adapted to passive sounding as compared with phase interference method.

• Periodical: Advanced Materials Research (Volumes 219-220)
• Pages: 846-850
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.219-220.846
• Online since: March 2011
• Authors: Tao Yu
• Keywords: Airborne Direction Finding, Direction Cosine Change Rate, Doppler Frequency, Electronic Warfare, Passive Location

References

[1] Zhao Guoqing, in:Radar countermeasure principle. Press of Xi'an Electronic Science and Technology University,1999. (CH).

[2] Qiao Qiang. Implementation Technology of Airborne Broadband Direction - finding System. Radio Engineering of China, 2005, 35(9):30-32.(CH).

[3] Xiao Changda, Zeng Maosheng. Simulation Test for Short Base Line Time Difference DF System. Electronic Warfare Technology, 2003,18(5):20-22,26. (CH).

[4] Yu Yang. The Improvement of Airborne DF Adjust Method Based on Four-channel Amplitude Comparison. Electronic Information Warfare Technology,2007, 22(3):24-26,39(CH).

[5] Li Yong, Zhao Guowei，Li Tao. Algorithm of Solving Interferomter Phase Difference Ambiguity by Airborne Single Position. Chinese Journal of Sensors and Actuators, 2006, 19(6): 2600-2602, 2606(CH).

[6] Zhu Zhaohui. Principle and Application of TDOA. Radio Engineering of China, 2006, 36(8): 51-52,64. (CH).

[7] Zhao Yefu, Li jinhua. Radio tracking measurement system. National Defense Industry Press, 2001. (CH).