WAAS G-III Receiver

The WAAS G-III provides accurate reference range measurements and signal quality measurements for ground reference networks. Designed for Satellite-Based Augmentation Systems (SBAS) that generate correction data and monitor signal integrity for safety-of-life applications, the WAAS G-III Receiver incorporates design features and signal processing techniques that have been proven and refined over three generations of development and testing.


  • Independent acquisition and tracking of GPS L1 C/A, L1C, L2C, L5 and GEO L1 C/A and L5 signals
  • Semi-codeless tracking of L2-P(Y) signals
  • Temperature controlled RF deck to minimize code and carrier phase shift
  • Chip-shape signal deformation measurements based on NovAtel Vision™ technology
  • Signal Quality Monitoring (SQM) measurements based on correlation peak shape measurements
  • RF interference protection and digital pulse blanking
  • Advanced cross-correlation and side lobe tracking detection
  • Adaptive phase-locked loop bandwidth for tracking in high-scintillation environments
  • Support for memory-based codes for experimental and maintenance activities

Support for modernized GPS signals

The WAAS G-III supports tracking, measurements, and integrity monitoring data for the modernized GPS signals. In particular the added support for the L5 signal allows for the evolution of ground systems to provide dual-frequency SBAS support for civil aviation applications.

Integrity monitoring

The WAAS G-III provides chip-shape measurement data for the monitoring of signal deformation effects caused by satellite analog hardware failure modes, as defined in the ICAO threat models. Traditional Signal Quality Monitoring (SQM) measurements based on correlation peak shape are provided for the legacy SBAS signals. The receiver software is designed for use-cases where GNSS integrity is impaired and SBAS corrections and/or alarms must be generated. Independence of tracking and measurement algorithms, and minimal filtering or processing of data is emphasized.

Robust operation

The WAAS G-III design provides robust performance under conditions of RF interference, pulsed in-band interference from radar and DME, scintillation, cross-correlation. Temperature control of the RF sections permits stable range measurements under conditions of varying ambient temperature. Initiated and continuous built-in-test features provide monitoring for hardware faults.

Built for ground networks

The WAAS G-III is housed in a rack-mount enclosure with forced air cooling and integral AC power supply. The hardware is completely re-designed with high-longevity components to minimize future impacts of component obsolescence. Extensive software stability testing has been carried out to assure continuous long-term operation in a 24/7 network. Hardware expansion features allow for expansion to support system evolution roadmaps.