Range to-go estimation for a tactical missile with a passive seeker

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Havacılık ve Uzay Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: SUZAN KALE GÜVENÇ

Danışman: ALİ TÜRKER KUTAY

Özet:

Throughout literature, tending to replace or improve Proportional Navigation Guidance, advanced guidance laws have been proposed. Most of these laws require the range between the target and the missile (range-to-go) which cannot be measured by passive seekers. The main objective of this thesis is to perform the estimation of range to a stationary target for a tactical missile equipped with a passive seeker. Two different approaches are investigated: the Method of Triangulation and the Extended Kalman Filter (EKF). The Method of Triangulation which is employed in a number of fields is used in this work to calculate the range between a stationary target and a moving missile. The sensitivity of this method to measurement errors in Inertial Measurement Unit (IMU) and seeker is studied. It is discovered that the error in range depends on the trajectory of the missile. This relationship is utilized to adjust the Constant Bearing Midcourse trajectory so that the range error is reduced to a certain level. Moreover, from sensitivity analysis, the problem of "geometric dilution" is identified and controlled to obtain a desired accuracy in range. Secondly, the estimation of range-to-go with an EKF is studied where the system model is formulated in terms of Modified Polar Coordinates (MSC) for 3D missile-target geometry. The estimation is performed from LOS (line-of-sight) angle and LOS rate measurements provided by the gimballed seeker. It is known that the performance of the filter depends on the observability of the scenario. To help to improve the performance of the filter when the observability is low, the EKF and the Method of Triangulation are integrated. The integration is carried out by taking the range output of the triangulation as one of the measurements provided to the EKF.