This paper presents a target altitude estimation approach based on multipath detections with range and range rate information from a two-dimensional (2-D) airborne radar. Using multipath detections has to deal with the following challenges: first, low probability of detection (PD) of the indirect path signal reflected by the sea surface; second, lack of an analytical expression for the relationship between the target motion parameter/state and the indirect path measurements over spherical earth; and third, unknown range measurement error standard deviation (s.d.) for the indirect path signal. Two estimators are developed: an adaptive multiple model iterated least squares (AMMILS) estimator for motion parameter estimation (noiseless target motion) and anAMM unscented Kalman filter (AMM-UKF) for dynamic state estimation (noisy target motion). Altitude estimate accuracy is studied based on simulation data. It shows that the AMM-ILS yields statistically efficient estimates (i.e., optimal and with a quantifiable accuracy), but this is not always true for the AMM-UKF. For a long distant target (e.g., 300 km) with very low indirect path PD (0.1 and 0.2), the AMM-UKF is inconsistent and inefficient statistically, due to biased estimation. The altitude Cramer Rao lower bounds from a 3-D radar with range and elevation measurements are also computed for comparison. The results show that the 2-D radar can provide better altitude estimates than the 3-D radar in most of the cases, except when the 3-D radar has accurate elevation measurement (with error s.d. σe = 0.5°) and the 2-D radar has very low indirect path PD (PD = 0.1).


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Altitude Estimation Using Multipath With a Two-Dimensional Radar Over Spherical Earth


    Contributors:
    Rong Yang (author) / Bar-Shalom, Yaakov (author) / Gee Wah Ng (author)


    Publication date :

    2018-04-01


    Size :

    822145 byte




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English





    Target Altitude Estimation in Over-The-Horizon Radar (Preprint)

    Y. D. Zhang / A. Ahmed / B. Himed | NTIS | 2019



    Towfish altitude computation using multipath acoustic ranging

    Trahan, R.E. jun. / Yeadon, D.S. / Thiele, M.G. jun. | Tema Archive | 1991