The Canadian Geophysical LBI System: Status and Future Plans

Abstract

Emphasis in the design of the Canadian Geophysical LBI (CGLBI) system has been placed on economy, operational efficiency, and performance in geophysical applications. Unique features of the system include the use of modified VHS recorders to store digitized astronomical data and the capability to track delay and fringe rotation during observation. A prototype system has been completed and tested at L-band using the ARO-DRAO interferometer baseline. The prototype system converts a single fixed 12 Mhz wide IF channel to baseband. Since delay resolution with this system is not sufficient for modern geophysical applications a frequency switching capability is being designed to synthesize a wide IF bandwidth while still maintaining the economy of a single channel system. Further improvements include the design of a phase cal detector and an input module compatible with NASA geodetic S/X receivers. Finally, efforts are being coordinated with ISTS so that record terminals developed for the Radioastron project can be interfaced to the CGLBI system.