Over-the-horizon radar surveillance sensor fusion for enhanced coordinate registration

Abstract

Redundant data from independent over-thehorizon radar systems can increase track accuracy by providing more independent "looks" at the target. With proper geometry, complementary radar system can aid in resolving uncertainties in the coordinate registration through the various ionospheric modes. Systematic positional differences between tracks from the separate radars can be used to improve the estimation of ionospheric heights. In operational systems, targets are tracked by multiple over-thehorizon radars in overlapping coverage areas. In this paper, we consider the case of two over-the-horizon radars. The main algorithm is designed to hand-off range bias errors from one radar's ionospheric mode to a second radar. It is expected that the resultant algorithmic development based on the work described in this paper will improve track positional accuracy by more than 50%.

Joint mode identification and localisation improvement of over‐the‐horizon radar with forward‐based receivers

“…Note that the proposed method in this paper mainly aims at estimating target height and ionospheric heights, and realising the joint identification and localisation improvement. Unfortunately, the algorithms mentioned in [6, 7, 16–20] are not suitable to solve the proposed problem. Hence, in the following simulation cases, method comparison is not considered.…”

“…Remark 2: Even if the ionosondes was available in neighbour interested zone, the obtained ionospheric data would still be not accurate because of spatial-temporal interpolation based on sparse sampling data [6,14,15]. It inevitably leads to errors in estimating ionospheric parameters and hence leads to systematic errors in the ground positions of targets.…”

“…Thus, introducing FBRs as external sources of information is expected to realise mode/parameter identification. Here mode identification and target localisation are deeply coupled and hence the joint identification and localisation is highly demanded. Remark 2 Even if the ionosondes was available in neighbour interested zone, the obtained ionospheric data would still be not accurate because of spatial–temporal interpolation based on sparse sampling data [6, 14, 15]. It inevitably leads to errors in estimating ionospheric parameters and hence leads to systematic errors in the ground positions of targets.…”

“…To date, there exist two kinds of approaches for OTHR target tracking. One utilises Kalman filters and data association in slant or radar coordinates, then involves in track fusion based on coordinate registration (CR), that is, the mapping between slant coordinates and ground coordinates [6, 7]. The other implements data association in slant coordinates and state estimate in ground coordinates and hence needs twice mapping between slant coordinates and ground coordinates.…”

“…Recently, much attention has been paid on introducing external sources of information, such as beacons or transponders [7, 16, 17], terrain features [17], additional OTHR systems [6] and passive receivers [18, 19]. The beacon‐assisted method focuses on correcting the ground coordinates of each raymode by an amount determined from the radar signal transponded by a beacon.…”