SVC was subcontracted by AlliedSignal to provide the guidance software upgrade for the Vandal EER (MQM-8) aerial target.  The Navy Threats and Targets Division based in Pt. Mugu required the Vandal target upgrade to include an autonomous guidance system based on GPS. On-board GPS positioning would alleviate the dependence on ground based radar guidance, and decrease operational cost.  SVC provided input into the selection and evaluation of the GPS sensor, and provided the software to integrate the GPS and inertial sensor in the existing guidance system.

      A challenging aspect to the program was the combination of high-dynamic launch conditions and severe vibration environment.  Most standard GPS receivers can only track up to around 7 g’s without the benefit of inertial aiding.  With inertial aiding, most GPS receivers specify a 12 to 15 g limit.  Off the rail, the Vandal accelerates at 15 g’s and there was great concern over finding a GPS receiver that could track in this environment.

      A receiver was identified that uses carrier-phase aiding in the tracking loop extending the dynamic capability to 20 g’s (spec) without the need for inertial aiding.  Space Vector assisted in the validation of the receiver under high dynamics by developing and performing the GPS constellation simulator test plan.  The receiver was further validated with sled tests exceeding 20 g’s, and a very successful flight test of the receiver on the Vandal target.