GHASP: a Galileo HAS parser

Abstract

Galileo High Accuracy Service (HAS) corrections are broadcast through the E6B signal using a high-parity vertical Reed-Solomon encoding scheme, which reduces message recovery time and improves transmission reliability. To recover HAS corrections, it is thus necessary to invert the encoding process and interpret the decoded bits. In order to foster HAS adoption and facilitate experimentation with HAS corrections, a Galileo HAS Parser (GHASP) has been developed. GHASP is available open-source and supports different input data types from different receiver manufacturers. Decoded corrections are provided in Comma-Separated Values files, which can be directly loaded using common data-science languages. In this way, corrections are readily available and can be used not only for Precise Point Positioning (PPP) applications but also for scientific analysis such as clock characterization using the Allan Deviation.