Introduction to nusar
nusar (Navigation User SoftwAre Receiver) is a flexible platform developed by GMV for processing GNSS open service signals in real time. It supports GPS and Galileo signals, including the new Galileo CBOC(6,1,1/11) modulation, and allows for the design and evaluation of advanced algorithms without the limitations of traditional GNSS software.

Main Features
nusar operates on a laptop and connects to a front-end and antenna. It offers APIs for easy algorithm implementation and inspection point creation. The software-based signal processing provides flexibility for rapid algorithm implementation and performance assessment. It processes GNSS Open Service signals in the E1-L1 band, including GPS L1 C/A and Galileo BOC(1,1) in real time, and supports both data and pilot channels for Galileo.

Modes of Operation
nusar supports three modes of operation:

• Online: Real-time processing of data from the front-end and antenna.
• Offline: Processing of stored data.
• Data Acquisition: Data collection and recording for offline processing.

Key Advantages
nusar provides a cost-effective environment for designing, benchmarking, and validating new algorithms through simple API definitions. It outputs measurements such as code delay, carrier phase, Doppler, CN0, lock time, and correlators’ information.

Use Cases
nusar has been used to track GIOVE-B and the first Galileo satellite by uploading the PRN file via its user-friendly interface. In December 2011, it tracked the first Galileo signal from PRN 11, processing both data and pilot components in separate channels. It can also process data from the srx10 front-end developed by GMV.