GBT Status Update
5 January 2001
The installation of NRAO equipment on the telescope is nearly complete. All Gregorian receivers are installed with the exception of the Q-Band receiver, which is undergoing lab testing. Installation and wiring in the Actuator Control Room is complete. The PF1, L-Band, and C-Band receivers are cold, and L-Band astronomical data have been passed from the telescope to the Jansky Lab and processed through both the Spectral Processor and the GBT Spectrometer, using its 800 MHz bandwidth mode.
The start of earnest astronomical commissioning has been delayed by two mechanical issues being addressed by the contractor, Lockheed-Martin. The first of these was the alignment of the elevation bullgear and mechanical stability of its individual segments. The bullgear alignment has been completed. Mechanical stability of the segments is much improved and may be acceptable for most modes of operation, although some additional reinforcements may be required. The second issue involves small movements in the wear strip segments on the azimuth track, which occur as the trucks bearing the weight of the antenna roll over them. While investigations into this problem proceed, a temporary, work-around is being implemented that will allow commissioning to begin while a permanent fix is developed. We expect that full astronomical commissioning, including movement of the telescope in both axes, will begin in late January. In the meantime, a rather full schedule of commissioning tests are commencing that do not require the telescope to be moved. These include bandpass and frequency tests, RFI characterizations, and software tests.
Major GBT milestones achieved since provisional acceptance on 28 September 2000:
5 Jan 2001