Photo: Systron Donner

Emcore achieved success in an ultra-high-altitude flight simulation conducted by CAST Navigation, which tested Emcore’s SDN500 inertial navigation system (INS).

Emcore is a provider of advanced mixed-signal products that serve the aerospace & defense and broadband communications markets.CAST Navigation builds simulators for testing and validating GNSS/INS performance in high-end navigation systems.

CAST used Emcore’s SDN500 inertial navigation system (INS) for the test, which required simulating performance at an altitude more than 24,000 meters and velocities over 600 m/s. Only a few aircraft in the world have such capabilities, including the SR-71 Blackbird, but it is not practical to participate in a test flight on the SR-71. Simulating the SDN500 INS test flight to specific customer profiles on a CAST system is straightforward and cost-effective.

Testing began with a stationary period on the ground while the SDN500 initialized and transitioned into air-navigation mode. Then the flight trajectory entered a series of maneuvers, speed and altitude changes that provided observability for various parameters with corresponding changes in the calculated figures.

Emcore relies on GNSS/INS simulators for hardware-in-the-loop testing to verify the expected performance of algorithms. Emcore CORE sought to validate the velocity and altitude limits of a new GNSS receiver along with the algorithm performance in a tactical-grade SDN500 system. In the final analysis, the GNSS receiver and navigation algorithm was confirmed to operate as expected throughout the operation for all three of the customer’s dynamic constraint scenarios.

“We were extremely pleased to demonstrate how Emcore takes advantage of the functionality contained in the CAST simulator to prove-out our robust product performance in customer environments,” said David Hoyh, director of sales and marketing for navigation products, Emcore..

“During the times when there was no valid solution from the GNSS receiver, the algorithm maintained an accurate solution using only the data from the IMU,” explained Andy Williams, senior field application engineer at Emcore who spearheaded the effort. “In addition, there was no algorithm instability or discontinuity when the GNSS receiver resumed, providing a solution to the algorithm. Throughout this entire profile, even when GNSS signal is lost, the SDN500 maintains an accurate navigation solution. This test is not possible without the synchronized GNSS radio frequency and trajectory matching IMU data provided by the CAST system.”

Source: “A True Reference. Theory Meets Reality in Synchronized Simulation Environments,” Inside GNSS, Volume 15/Number 5, September/October 2020, Pages 28, 29, 30.