From Nigel Sun Aug 31 23:28:08 1997 From: Nigel (Nigel) Date: Sun, 31 Aug 1997 23:28:08 PDT Subject: [IGSMAIL-1676] Modification of Rogue Antenna Fence at Tidbinbilla Australia Message-ID: ****************************************************************************** IGS Electronic Mail Sun Aug 31 23:28:08 PDT 1997 Message Number 1676 ****************************************************************************** Author: Nigel Chauncy Tidbinbilla SPC-40 Australia Subject: Modification of Rogue Antenna Fence at Tidbinbilla Australia Subject: Modification of Rogue Antenna Fence IGSmail Just a quick note to inform you that we have made some changes to the fencing around the Rogue Antenna at the Canberra deep space communication complex at Tidbinbilla. During a recent visit to SPC-40 by Arthur Neil from Haystack we had some discussion about the fencing arrangements surrounding our Rogue antenna. It is possible that the previous arrangements, which include solid horizontal timber beams above the height of the antenna, may have been interfering with the received signal, especially when tracking SVs at low elevations. To solve this problem we have removed the top rail. While removing the top rail I took some measurement to find the angle that the fence was above the antenna(With some simple trigonometry?;>) At the closest point the angle was about 9 degrees With the top rail removed the angle was reduced to about 2.5 degrees. In the interest of deterring any cows or Kangaroos from getting into the compound we have replaced the top rail with some nylon rope (5mm dia). We made this change on Monday 25th August. Before the removal of the top rail we had logged the snr's from the receiver for all sv passes. We have continued logging the snr's, to try and get some comparison to see if it made any difference. These very large MS Excel are available if any one would like to look at them. From what I can gather from the data our change in fencing arrangement has made very little difference. If you have any questions or advice please lets us know. Regards Nigel. Email: Nigel.C.Chauncy at jpl.nasa.gov or nchauncy at tid.cdscc.nasa.gov [Mailed From: Nigel C Chauncy ]