A Co-operative Anomaly Resolution on PRN-19

Abstract

In March of 1993 there was a considerable amount of public attention focused on an unusual anomaly associated with GPS-PRN-19. Non differential GPS users did not notice a bias introduced by PRN-19 as it was within the specified SPS accuracy. However, when PRN-19 was included in a L1 C/A differential equipment solution it would offset the position from 3 to 8 meters depending on different types of user equipment. The intent of this paper is to describe that anomaly in general terms and focus on the process and organizations involved in the anomaly resolution used at that time. Further, the intent is to recognize the contributions of the civilian organizations and credit those civil individuals involved in the resolution of this anomaly.