Aerospace Instrument-Making Annotation << Back Operational measures for GLONASS performance improvement under negative geo-space environment Likhota R.V. The main advantages and disadvantages of the modern GPS positioning im-provement methods are considered on a basis of positioning integrity and availability criteria. We conducted some GPS positioning accuracy observations under geomagnetic storm and Solar radio flux condition. We propose a complex of operational measures which provides positioning integrity and availability improvement for GLONASS users under unfavorable geophysical condition. The new structure of GLONASS/WAAS performance monitoring and positioning and integrity quality forecasting system is provided. The above mentioned system is recommended as the necessary part of future development GNSS service which provides exact monitoring and forecasting of GNSS performance quality for high requirement of positioning quality on transportation applications. Key words: GPS/GLONASS positioning quality; integrity monitoring; positioning availability forecasting. Contacts: E-mail: Likhotar@mail.ru Pp. 17-25.