15/05 135/22:15-00:00
Array = 6D
W8 W32 W84 W168 W173 W392
Refant:
135/22:15:00-135/22:51:46 CA00 135/22:51:46-135/23:55:12 CA05 135/23:55:12-136/00:00:00 CA03
RefAntCal:
135/22:15:00-135/23:55:12 CA05 135/23:55:12-136/00:00:00 CA03
Tied IF#1: —-5-
Tied IF#2:
135/22:15:00-135/22:42:36 ---45- 135/22:42:36-135/22:49:34 ----5- 135/22:49:34-135/22:51:57 12345- 135/22:51:57-135/23:01:29 ----5- 135/23:01:29-136/00:00:00 ---45-
SOE sent by Graham Baines
Briefing Message For DSS-34 DOY 135 22:15 to 00:30z Asteroid Support
Baines, Graham
Tue 5/15/2018, 4:40 PM
DL-CDSCC Operations;Neuendorf, Terry;Kruzins, Ed;Horiuchi, Shinji
Ops,
On DOY 135 between 22:15 and 00:30z (DOY 136) DSS-34 will be supporting an X-Band solar system radar experiment in conjunction with the Compact Array at Narrabri. DSS-34 will provide the transmitted signal and the Compact Array will receive the echo from asteroid 2010 WC9. At the point of closest approach which happens at 22:03:55z the asteroid will be just half the Earth – Moon distance from Earth.
The following lists the activities for the experiment. The sequence of events in summary is:
22:15z Beginning of activity (or earlier if possible)
Build a link for SC 0026 including the antenna, microwave, and X-Band uplink
If it’s still to be done, load predicts into the UPL and APCA for Asteroid 2010 WC9 (refer to Terry Neuendorf e-mail attached)
Note that the APCA predicts need to be extracted from: 2010wc9.PRDX.OUT.34v-47-47.s15 (available from the SPS adhoc area under my name)
Calibrate the X-Band transmitter for 20 kW, RCP out of the antenna
Start with The ZA UPL predict set
ASAP Antenna on point at Asteroid, Transmitter ON (as early as possible)
23:25 Uplink disabled, new ZB predict file selected, Uplink enabled
(second predict file will span 23:20 to 00:40z)
(expect ~30 second break in uplink to make the swap)
00:00 Transmitter OFF, End of experiment
00:30 End of activity, tear down link
Hopefully in the morning I’ll have a Narrabri contact number and Web address where we can monitor the recorded Narrabri spectrum.
Narrabri intend to start with just two antennas, CA04 and CA05. These will be the closest to each other at the time at Narrabri. More antennas may be added at Narrabri’s discretion as the observation advances.
Regards,
Graham.
Email distributed by Graham Baines
Possible 2010 WC9 (s15) Support Planning
Baines, Graham
Tue 5/15/2018, 1:02 PM
Philip.Edwards@csiro.au;Jamie.Stevens@csiro.au;Horiuchi, Shinji;Kruzins, Ed Phil,
Things are now coming together for this activity.
In order to minimize the effects of linear ramps between transmit frequency points, I’ve asked for and propose to use transmit frequency predicts with a 10 second spacing between points. Based on the rule-of-thumb rule I presented at the January Solar System Radar Meeting we all attended, this suggests no more than +/- 0.1 Hz received frequency noise caused by the interpolation of predicts. There’s also another limitation we need to consider – the predict file can contain no more than 500 predict points. To get around this I propose creating two overlapping predict files for tomorrow’s activity. We will start with one and switch to the other before the first one runs out of points, this necessitating a short break in the uplink (a few tens of seconds at most).
The sequence of DSS-34 activities tomorrow then will be (all times AEST):
08:15 Commence setup of DSS-34 equipment (we can start no earlier) (first predict file will span 08:10 to 09:30)
ASAP On point, Uplink enabled
09:25 Uplink disabled, new predict file selected, Uplink enabled (second predict file will span 09:20 to 10:40) (expect ~30 second break in uplink to make the swap)
10:00 Uplink disabled, DSS-34 to stow, end of activity
As mentioned before, the CDSCC contact telephone number will be: 62 017 940
Jon Giorgini (my predicts provider at JPL) also told me the following:
For the orbit solution from which the predicts are derived (#15), the worst case 3-sigma formal uncertainties are:
Pointing is a little rough at +/- 13 arc-seconds during the rapid sky motion of closest approach.
Frequency predicts should be within +/- 6 Hz, albeit that is for a single reference point in the ATCA array and depending on what dishes are involved and where they are, there could be a wider spread.
The first point suggests to me that your shortest baseline two-antenna array using CA04 and 05 is probably a wise approach so that the array doesn’t miss the asteroid because of predict uncertainty.
Regards,
Graham.
