The Multi-output Advanced Signal Test Environment for Receivers (MASTER) is a unique and powerful hardware simulator for testing and evaluating the quality of GNSS receivers (also with array antennas). MASTER allows the simulation of a complete GNSS constellation, offering full control over the definition of individual satellite orbits, user-specific location or movement patterns, date and time, as well as orbital position errors, timing errors, ionospheric and tropospheric influences, multipath propagation and interference. Each scenario defined in this way can be repeated as often as desired with the exact same parameters.
The MASTER system consists of two modified Spirent GSS7790 hardware simulators that can simulate the GPS and Galileo constellations simultaneously. The system generates all GPS (L1, L2, L5) and Galileo (E1, E5, E6) satellite signals, which are accessible on the carrier frequency as well as on an intermediate frequency or in the baseband for each satellite individually. The user can select individual signal components such as data or pilot channel, navigation messages or random noise. In addition, interference can be generated via an external signal generator and superimposed on the satellite signals.
Typical applications of MASTER include testing Galileo and GPS receivers in a quasi-realistic environment under controlled and repeatable conditions, wide-ranging tests of specific procedures to suppress errors due to multipath propagation and interference, testing antenna arrays with digital beamforming and to determine alignment and attitude, as well as testing ground-based augmentation systems and calibrating time receivers.
The accessibility of the digital baseband signals is a unique feature of MASTER that does not exist in this form in conventional simulators. This makes it possible to simulate multi-antenna receivers as well.
Image: Markus Steur