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Number crunching :
24jl12ag WU true angle range is : 115.077961
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Josef W. Segur Send message Joined: 30 Oct 99 Posts: 4504 Credit: 1,414,761 RAC: 0 |
We've seen similar cases before, caused by the WU being partially recorded before the recorder paused because the ALFA receiver was shut down, and partially after. I'm not sure that's the case here, 24jl12ag.3747.1383.249108103178.12.109 has just this set of coordinates: <coords> <coordinate_t> <time>2456133.1839483</time> <ra>8.7091553497447</ra> <dec>15.636017362896</dec> </coordinate_t> <coordinate_t> <time>2456133.3506134</time> <ra>12.724331975981</ra> <dec>15.835476136371</dec> </coordinate_t> <coordinate_t> <time>2456133.1851898</time> <ra>8.7390644689903</ra> <dec>15.637503134705</dec> </coordinate_t> </coords> For the first two coordinate sets, both the time fields (in Julian day format) and the ra values indicate ~4 hours, which corresponds to ~60 degrees of earth rotation. But then the third set of coordinates goes back in time and ra by nearly as much. That's another ~60 degrees of course, but I've never seen a negative time interval before. Whatever, the true_angle_range is the sum of the motion between each pair, and we process the tasks as if that amount of motion occurrred over a 107.374 second interval. IOW the results aren't scientifically valid, it's a GIGO case. Joe |
Josef W. Segur Send message Joined: 30 Oct 99 Posts: 4504 Credit: 1,414,761 RAC: 0 |
... That one's more typical, 104 coordinate sets from one observation, a ten hour gap, and 6 coordinate sets from the beginning of a new observation. I don't know how common they are either. Arecibo seems to schedule observation time of no less than 1 hour, but I have one saved from two years ago which ended up with true_angle_range 347.22480029913 because the ALFA receiver was brought up for very brief periods a couple of times during a longer gap. Joe |
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