LAUSR

Abstract Using a portable star tracking system, the geographical position of the observer, latitude, longitude, and the North direction were obtained. In the previous work, the accuracy of latitude and longitude were obtained as 932 and 1510 m, respectively. The weakest point in the previous work was the installation of the charge-coupled device (CCD) on the inclinometer which had the largest uncertainty in the procedure of positioning. Therefore, a method was presented to calculate the angle between the CCD and the inclinometer. In this work, a new optimization method is applied to improve the accuracy of the calculation of observer position to 147  m in Latitude and 171  m in Longitude. In this method, 80 to 100 stars are used in each picture taken of the sky to apply the optimization method. To obtain the accuracy, 50 nights’ observations were recorded. On each night, 100 quite independent images were taken.