APNT Software

General Dynamics’ alternate Position, Navigation and Timing (aPNT) Software provides resilient position, velocity and time (PVT) information when GPS is not available. aPNT Software utilizes two-way/time transfer (TWTT) measurement and other space vehicle sensor/clock inputs to provide PNT solutions. These solutions benefit from Global Navigation Satellite Systems (GNSS) data (if available), but do not rely upon GNSS data to meet requirements. It is a mature GNSS-independent TWTT solution that is adaptable, easy-to-integrate, and hardware and operating system agnostic. The software is a container-based configuration item, providing PVT solutions in the event of GPS outage with a trust engine/integrity audit capability. It validates GNSS-derived PVT solutions using Intra-Satellite Links (ISLs) time transfer and training information, and is configurable via input parameter selection, operating with selectable combinations of optical communication terminal and Ka-Band input data. Initiated for SDA T0 Transport SVs, it has been baselined for several SDA T1 Layers & SV Designs, and is mature and ready for flight, already baselined for several small satellite contracts.