Precision analysis for TDOA TDOS localization

DOI:	10.11809/bqzbgcxb2024.01.033
Keywords:	time difference of arrival; time difference of scan; localization precision; Cramer Rao lower bound; passive location
Abstract:	This paper proposes a simple and efficient framework for locating a stationary or slowly moving radar with periodic scan, using the time difference of arrival (TDOA) and time difference of scan (TDOS) measurements obtained at two spatially distributed sensors. The TDOA TDOS source localization problem is first formulated, and a closed form solution is then established. Besides, the Cramer Rao lower bound (CRLB) of the unknown source position is derived, which enables the analysis on the impact of measurement noise and sensor altitude errors on the localization accuracy. Numerical results verify empirically that reducing the TDOA and TDOS measurement noise, enlarging the inter sensor distance (i.e., the baseline length), or decreasing the errors in the known sensor positions can lead to evident improvement in the localization performance. Under the typical scenario where the standard deviation of the measured TDOAs and TDOSs are 20 ns and 0.001 degrees, the location accuracy of the radar with a scanning period of 3 seconds can be as low as 50 meters at the distance of 450 km from the centroid of the sensor array.
Published:	2024-01-28
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