A RFI Testbed for Examining GNSS Integrity in the Various Environments

Abstract

A testbed is built for examining the GNSS integrity under RFI for aviation environment. The combination of hardware and software enables us to simulate the RFI and GNSS environment on the aircraft in the laboratory. Considering existing different jamming types and power level effect on the GNSS integrity, several jamming type data sets are pre-generated and jamming power is adjustable by setting the transmitter gain. The receivers collect the raw measurements needed for protection level computation or output built-in protection level. The algorithm to compute the protection level is the multiple hypothesis solution separation algorithm (MHSS). Then, convert the protection level to Navigation Integrity Category (NIC) which is a field in Automatic Dependent Surveillance-Broadcast (ADS-B). Three receivers from surveying to consumer grade are tested for examining different responses of receiver brands.