NavTEL-a powerful analysis tool in the process of validating C-130 SCNS GPS/INS integration design

The 46th Test Group's 746 Test Squadron has developed the Navigation Test and Evaluation Laboratory (NavTEL). NavTEL is a state of the art test bed which provides integrated GPS navigation systems with a development, integration, and test and evaluation environment. The facility allows hardware and software of the integrated GPS system to be exercised under laboratory conditions by a real-time simulation of L1 and L2 GPS satellite signals, host vehicle navigation sensors, and host vehicle communications. Smiths Industries, the integrator of the C-130 self contained navigation system (SCNS), discovered a problem with INS velocity spikes within the Collins GPS receiver 3A (3A) which were creating velocity biases in the background navigation data. Real time display of data provided a quick look analysis tool for the velocity spike impacts on the 3A background navigation solution. This paper discusses the design of the NavTEL architecture and data display tools as well as the test methodology that allowed the 746th Test Squadron to quickly duplicate the C-130 SCNS problem in the laboratory and validate proposed solutions for the velocity spikes/bias on the 3A receiver output.