Observations 02 June 2007:
----------------------------
Cosatrak 1 (Computerised satellite Tracking System).
MINTRON low light level CCD surveillance camera (0.005 lux typical
in non integration mode) and 0.00005 lux in STARLIGHT mode with 128
frame integration.
Used with 50mm focal length f/1.8 lens,integrating for 96 frames
which is equivalent to an exposure of 1.92 seconds per image.
Site 0433 : Longitude 18.51294 deg East, Latitude 33.94058 deg S,
Elevation 10 metres - situated in Pinelands (Cape Town), South Africa
OPS 9845 - DMSP mag 5.5 to invisible - variable
13736 82 118A 0433 F 20070602163519400 56 15 1044170+160906 39 +055 05
SL-14 R/B Mag +6.5 steady
12880 81 098B 0433 F 20070602164602900 56 15 1043380+163042 39 +065 05
OPS 8364 - DMSP mag 6.0 to invisible - variable
06787 73 054A 0433 F 20070602165201500 56 15 1048460+192406 39 +060 05
Cosmos 1707 mag 4.0 steady
16326 85 113A 0433 F 20070602165535100 56 15 1039260+160944 39 +040 05
SL-14 R/B mag 6.0 steady
19791 89 009G 0433 F 20070602165954200 56 15 1111240+151801 39 +060 05
SL-8 R/B mag 3.0 steady
25723 99 022C 0433 F 20070602171510100 56 15 1124430+161901 39 +030 05
Iridium 69 mag +5.0 variable
25319 98 026A 0433 F 20070602171542800 56 15 1059310+175940 39 +050 05
Thor Agena rocket mag 4.5 steady
01245 65 016J 0433 F 20070602172030400 56 15 1107480+182432 39 +045 05
Iridium 76 mag 6.0 steady
25432 98 048B 0433 F 20070602172038600 56 15 1129060+190041 39 +060 05
SJ-6D mag 3.5 steady
29506 06 046B 0433 F 20070602173313400 56 15 1130060+162208 39 +035 05
Argos mag 6.5 steady
25634 99 008A 0433 F 20070602174549700 56 15 0922440+093136 39 +065 05
Atlas 5 centaur mag 7.0 variable, range 8670 kms
28473 04 048B 0433 F 20070602175953100 56 15 0950500+162519 39 +070 05
Meteor 1-26 mag 6.0 steady
09481 76 102A 0433 F 20070602180442400 56 15 0948390+114024 39 +060 05
Delta 1 Rocket body mag 6.5 steady, range 3240 kms
14051 83 041B 0433 F 20070602181419700 56 15 0946190+112021 39 +065 05
SL-8 R/B mag 7.0 steady
18710 87 106B 0433 F 20070602181543000 56 15 1003200+132321 39 +070 05
Delta 2 R/B mag 6.5 steady, range 3250 kms
21965 92 027B 0433 F 20070602181737500 56 15 0954320+111940 39 +065 05
Delta 1 R/B mag 7.0 steady
10517 77 118B 0433 F 20070602185058200 56 15 1036080+134512 39 +070 05
Delta 2 R/B mag 6.5 steady, range 2620 kms.
24809 97 025B 0433 F 20070602185647600 56 15 1043170+164839 39 +065 05
Notes:
--------
(1) Satellites observed whilst looking for unknowns - nothing particularly
exciting about them.
(2) Am now occupying my time with improving the determination of orbital
elements of unknown satellites and have made some very good progress.
Using the method of Gauss ( 3 times and three positions) I am now able
to determine the parameters of most satellites to within a few percent
of the actual value at the time of observation - ALL the parameters are
very close to the actual values except for a few percent error in the
orbital period - usually of the order of 3 - 5 minutes after one day
but in some cases within 5 minutes after 5 days. This applies to LEO
as well as MEO satellites eg 63 degree inclination, mean motion
around 2 revs per day. The procedure generates 18 equations in 18
unknowns but using the Lagrange coefficients f and g, as well as
using the Stumpff functions and state vectors etc and applying the
conservation of angular momentum, some valid approximations can be
made which gives an initial solution, then by a process of iteration
one homes in on the correct values that fit the observations.
Full details of the method used may be found in "Orbital Mechanics
for Engineering Students" by Howard D.Curtis (2005) - an excellant
book on ALL aspects of orbital mechanics with lots of problems and
detailed solutions. Preliminary tests indicate that a minimum arc
covering 2 - 3 minutes in time is necessary to get the right answer.
Anything less will only provide the RA of Node and the inclination.
For the approximations made in the computation it is not wise to use
too long an arc and a maximum of 10 degrees of the satellites orbit is
recommended in the literature.
Further testing is being done but so far results are extremely
encouraging - ( something I did NOT expect when I started as I did not
consider it possible to derive an eccentric orbit from a very small
arc of the satellites orbit!)
Cheers
Greg
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