Absolute Alignment of Sensors.

Abstract : Absolute alignment refers to the process of determining the true bias or offset errors in the data reported by a sensor. This report develops an algorithm for absolutely aligning the positional data reported by a tracking sensor using a target whose location is measured by the sensor and whose location can be precisely determined by some technique independently of the sensor's measurements. The algorithm also requires the location of the sensor to be precisely known. Any differences between the sensor-reported position of the target and the independently determined precise target location is attributed to bias errors in the track data reported by the sensor. These differences can be used to estimate the bias errors in the track data. A potential candidate for providing precise location information independently of the sensor's measurements is GPS (Global Positioning System). However, the algorithm is applicable to any technique that provides precise location information independently of the sensor's measurements. Simulation results are presented to illustrate the performance of the absolute alignment algorithm developed in this report.