Inertial Frame Projection Using Multi-Static Interferometry in a Dynamic Environment

Propagation Research Associates, Inc., (PRA) proposes to develop and demonstrate a Localized Positioning, Navigation, and Timing (LPNT) frame projection methodology using a Multi-Static Interferometer (MSI) in a dynamic environment.  An MSI located on an airborne platform can establish an inertial frame for weapon location that can also be projected forward to support long range mission applications.  The dynamic airborne platform enabled with a MSI will present challenges in establishing an accurate LPNT system. PRA will investigate two applications that require accurate location for airborne platforms at long ranges.  The first application is to guide a platform to a point where an on-board sensor can execute weapons delivery.  The second application is to cue off-board weapons for delivery to targets and will also require guiding a WEP to a point in space allowing an on-board EO/IR sensor to locate targets in a projected coordinate frame that is aligned with an inertial MSI frame.  In this second application, frame alignment is required from either a global inertial frame or the MSI inertial frame to the sensor frame on the platform in order that target location can be communicated to an inertial frame for weapon targeting.  For the first application, only local platform alignment is required for targeting since the weapons are guided locally from the platform.  In both applications, the MSI frame is projected forward for platform guidance to a VPS that is chosen to optimize engagement performance. MSI frame projection is enabled using multiple distributed antennas to create an energy field using unique waveforms where forward deployed weapons can operate.  Thus, the trajectory of the MSI host platform must be able to establish this energy field over the entire engagement time. Using inertial sensors on the host platform MSI six degrees of freedom motion can be measured in an inertial frame over the engagement time.  An energy field is created by the unique waveforms transmitted by the MSI. As a result, the inertial frame is projected onto each platform in the energy field.  The objective of this proposed effort is to develop a localized positioning, navigation, and timing (LPNT) system that can achieve sufficient location accuracy with minimal bias for dynamic platforms at long range from an enabling RF illuminator that can be operated on an aircraft.  PRA will demonstrate the proposed LPNT system in a field test using a scaled version of the MSI.