A Novel TOA measurement based global evolutionary search estimator for defence applications

Abstract

Time of Flight (TOF), popularly Time of Arrival (TOA) is the time a radio signal takes to reach the receiver from a remote transmitter. TOA measurements are broadly used for source localization and position fixing in civil and defence applications. The accuracy in position fix is primarily influenced by factors like error in TOA measurements and position estimation solution employed. Though the accuracy and precision in position estimate are acceptable to tens of meters in civil applications, there are radio-navigation systems like GPS in defense, demand mill-meter level accuracy. Defense systems like CAT I & II air craft landing, missile guidance and tracking need high precision in position estimate. This paper focuses in developing a new TOA based precise navigation solution, grown out from the inherent features of traditional Least Squares (LS) and Global Evolutionary Search (GES) Estimators. To validate the algorithm, real world data collected from Dual Frequency GPS (DFGPS) receiver located at IISC, Bangalore (Lat/Lon: 13.01 o N / 77.56 o E) is used and Position accuracy measuresCircular Error probable (CEP), Spherical Error probable (SEP), MRSE (Mean Radial Spherical Error) and Distance Root Mean Square (DRMS) are used to analyse the algorithm performance.