Understanding signals from glonass navigation satellites

In late 1986 details of the radio‐frequency signal structure currently employed by the pre‐operational GLONASS satellite navigation system were revealed by the Satellite Communications Group at Leeds University. Since then further investigation has resulted in a successful interpretation of most of the data message transmitted on the civil code, sufficient to allow the design and construction of a GLONASS receiver capable of the same level of performance as can now be achieved with NAVSTAR GPS. Details of the message content relating to location of GLONASS satellites for the purposes of position‐fixing and time‐referencing are presented for the first time.