Practical Issues and Guidelines in Handling Erroneous Secondary Radar Measurements in Multi Target Tracking

This paper develops methods to circumvent the issues in track initiation and track maintenance that can occur in radars with primary and secondary measurements. In a combined Primary and Secondary radar surveillance applications the measurements from secondary radar (Identification of Friend or Foe IFF) along with primary radar constitute another category of measurements referred as associated measurements. This paper describes the possible types of erroneous measurement that can occur under the combined Primary and Secondary radar surveillance applications. Ideally one target should produce only one measurement (Either primary, secondary or associated) from radar for a given time and also with unique IFF code. But, in practice due to various reasons there can be (a) primary and secondary measurements for same target, - due to the failure of combining logic (b) multiple secondary and associated plots for same target - due to the issues in secondary radar side lobe reflections. The methods developed in this paper first identify the presence of multiple measurements from same target and then utilize these measurements to improve the estimation accuracy. The developed methods shows that by incorporating measurements from primary and secondary radars improved estimation accuracy can be obtained while in case of multiple secondary radar measurements the using only the nearest measurements yields best results. The developed logics are explained in this paper using detailed flow charts. The abnormal detections and the root cause analysis carried out in this paper are based on the practical knowledge obtained by handling various real time radar recordings collected from the field.