Observations 05 May 2003:
---------------------------------
Cosatrak 1 (Computerised satellite Tracking System), 1004x low
light level CCD surveillance camera (0.003 lux) with new 110mm
aperture lens working at about f/1.6.
Site 0433 : Longitude 18.51294 deg East, Latitude 33.94058 deg S,
Elevation 10 metres - situated in Pinelands (Cape Town), South Africa
25615 98 055C 0433 B 20030505165243400 17 15 1231404-233145 39 S+050 05
25615 98 055C 0433 B 20030505165357600 17 15 1345131-470743 39 S+050 05
25615 98 055C 0433 B 20030505165442600 17 15 1446529-560804 39 S+050 05
25615 98 055C 0433 B 20030505165502900 17 15 1517397-584457 39 S+050 05
23233 94 057A 0433 B 20030505170756500 17 15 1444345-550500 39 S+075 05
23233 94 057A 0433 B 20030505170959500 17 15 1216411-264229 39 S+074 05
23233 94 057A 0433 B 20030505171017000 17 15 1201233-203949 39 S+073 05
23533 95 015A 0433 B 20030505171137100 17 15 1223575-422950 39 S 05
23533 95 015A 0433 B 20030505171158500 17 15 1159318-351830 39 S 05
23533 95 015A 0433 B 20030505171257500 17 15 1107263-124020 39 S 05
11389 79 050A 0433 B 20030505171520300 17 15 0747400-383020 39 V+051 05
11389 79 050A 0433 B 20030505171602700 17 15 0745000-174333 39 V+059 05
11389 79 050A 0433 B 20030505171640300 17 15 0742377-020906 39 V+063 05
08835 76 038C 0433 B 20030505173339200 17 15 0611212-142353 39 V+076 05
08835 76 038C 0433 B 20030505173402800 17 15 0630267-084118 39 V+078 05
08835 76 038C 0433 B 20030505173402800 17 15 0630267-084118 39 V+078 05
25157 98 007A 0433 B 20030505173645500 17 15 1426505-451354 39 V+073 05
25157 98 007A 0433 B 20030505173708200 17 15 1442402-524403 39 V+061 05
25157 98 007A 0433 B 20030505173806700 17 15 1600139-684322 39 V+063 05
14112 83 056A 0433 B 20030505180459200 17 15 0708124+092915 39 V+080 05
14143 83 056C 0433 B 20030505180944900 17 15 0543261-200509 39 V+084 05
14143 83 056C 0433 B 20030505181024300 17 15 0615411-120355 39 V+082 05
14143 83 056C 0433 B 20030505181041400 17 15 0629501-080712 39 V+082 05
07816 75 043A 0433 B 20030505182000300 17 15 0639008-065214 39 V+082 05
16591 86 014A 0433 B 20030505182722600 17 15 0455105-655708 39 S+078 05
16591 86 014A 0433 B 20030505182739900 17 15 0529148-663335 39 S+076 05
16591 86 014A 0433 B 20030505182758800 17 15 0613487-663713 39 S+075 05
25744 99 028A 0433 B 20030505184035100 17 15 0707071-405336 39 V+060 05
25744 99 028A 0433 B 20030505184101000 17 15 0718335-391237 39 V+070 05
25744 99 028A 0433 B 20030505184457900 17 15 0847174-184938 39 V+079 05
25744 99 028A 0433 B 20030505184516700 17 15 0853054-165708 39 V+067 05
90013 03 564A 0433 B 20030505193135600 17 15 1333586+032510 39 V 05
Notes:
(1) Conditions very poor - initially very thick cirrus which more or less
cleared overhead but replaced by very heavy dew which clouded up the
lens most of the session and eventually forced me to stop observing.
(2) First test of new camera lens - about 4.25 inch aperture and working
at about f/1.6. It did not start life as a camera lens so it was
questionable whether it would be of any use. However initial tests
show that there is little or no field curvature and images are sharp
and small.
However on analysing the video tape made it was found that the contrast
is very low - this could be partly due to the cirrus/dew but I suspect
I will have to try and add at least one field stop to increase contrast.
Theoretically the lens should give me an extra 1.5 to 1.7 magnitudes on
my previous 82mm focus f/1.6 lens. Observations show a gain of about 0.5
to 0.6 magnitude.
The field of view is about 0.69x of what I previously had so hopefully
positional accuracy will increase - the satellites also now appear to
move a lot faster.
(3) Winter has now arrived in Cape Town so cloud and very heavy dew are
commonplace . Despite a lens hood dew was a serious problem so I plan
to divert the hot air coming out of the ccd box (which has a cpu fan
on it to cool the ccd circuit board ) to flow over the lens and keep
it warm.
(4) Due to cirrus and dew/mist magnitude estimates are questionable.
Cheers
Greg
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This archive was generated by hypermail 2b29 : Tue May 06 2003 - 13:13:28 EDT