Phase observations of GPS satellites processed by the ERA program system.

Institute of Applied Astronomy, 8 Zhdanov street, 197042, Saint-Petersburg, Russia

ERA is the programming system developed at the Institute of Applied Astronomy for solving a wide range of tasks of ephemeris and dynamic astronomy including GPS applications. The ERA's built-in applied program package includes software for accurate dynamic modelling of Earth's satellites and comparing the dynamic model with observations of varied types. The IERS standard for the model is used when possible. The system was tested by processing pseudorange and phase measurements of GPS and GLONASS satellites. For phase observations of GPS satellites the method of third differences was used. There are two types of the observational campaigns which have been used for testing - a local campaign ( measurements made at the local geodetic net of the Zelenchukscaya station of the IAA ) and a regional one ( international campaign PEKA- 93,94 on the North Caucasus ). Results for the local campaigns are in a good accordance with those obtained with the help of other available program packages. Processing the regional campaign is at work.