Unknown Radio Source Localization Based on a Modified Closed form Solution Using TDOA Measurement Technique

There have been huge advances in the development of positioning applications after the success of GPS. Accurate positioning capability of a radio source is in great demand in the fields of medicine, defence, automation etc. Especially in the Indian subcontinent, localization of an unknown enemy Radio Source such as an enemy radar system, tracking of Unmanned Aerial Vehicle (UAV) etc are essential capabilities for the defence wing. The time difference of arrival (TDOA) technique used for location determination makes use of the method of hyperbolic multilateration. Position accuracy is affected by various factors such as choice of number of sensors, measurement noise, algorithm employed for positioning and sensor geometry. A number of positioning algorithms are available for this purpose. These include iterative algorithms, evolutionary algorithms and many others that are not particularly feasible as the run time of the hardwired code is a major constraint in real time applications. A closed form algorithm proposed in the literature achieves considerable speed in implementation but falters in the resolution of the altitudinal estimate. Hence, a modified algorithm is proposed in this paper that resolves the altitude of the unknown radio source. For better understanding, an example of localizing an unknown radio source using the proposed algorithm is explained.