Satellites
Satellite Observing
When you look up at the night sky, you will notice moving points of light. These moving points of lights, are earth orbiting satellites.
Types of Satellite Orbits
Geosynchronous
A orbit in which a satellite travels at the same angular speed of the earth's rotation. So it appears to hover over a certain spot of the earth. And so they don't drift out of the feild of view. This applies only to one's parked over the earth's equator. If the have highly inclined orbits, then the satellite will drift out of the feild of view.
Polar
A orbit that allows the satellite to pass over the earth's north are south poles. It orbit would be inclined 90 degrees to the equator.
Sun Synchronous
There orbit is fixed with respect to the Sun, so that this causes the satellite to pass overhead at the same local time each day. This makes it harder to see them compared to other satellite in a different type of orbit. Inclination of orbit is 98 degrees.
Retrograde
This orbit is inclined more then 90 degrees to the equator. So these satellites will travel in the reverse direction of the earth's rotation. So these satellite rise in the ease and set in the west. Satellite usually travel west to east, the direction of the earth's rotation. Seasat is a bright satellite in a retrograde orbit.
Orbital Data ( TLE )
These are data on the various values, that make up the orbit of a satellite.
Below info from http://www.celestrak.com
Data for each satellite consists of three lines in the following format:
AAAAAAAAAAAAAAAAAAAAAAAA 1 NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN 2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN
Line 0 is a twenty-four character name (to be consistent with the name length in the NORAD SATCAT).
Lines 1 and 2 are the standard Two-Line Orbital Element Set Format identical to that used by NORAD and NASA. The format description is:
| Line 1 | |
|---|---|
| Column | Description |
| 01 | Line Number of Element Data |
| 03-07 | Satellite Number |
| 08 | Classification (U=Unclassified) |
| 10-11 | International Designator (Last two digits of launch year) |
| 12-14 | International Designator (Launch number of the year) |
| 15-17 | International Designator (Piece of the launch) |
| 19-20 | Epoch Year (Last two digits of year) |
| 21-32 | Epoch (Day of the year and fractional portion of the day) |
| 34-43 | First Time Derivative of the Mean Motion |
| 45-52 | Second Time Derivative of Mean Motion (decimal point assumed) |
| 54-61 | BSTAR drag term (decimal point assumed) |
| 63 | Ephemeris type |
| 65-68 | Element number |
| 69 | Checksum (Modulo 10) (Letters, blanks, periods, plus signs = 0; minus signs = 1) |
| Line 2 | |
|---|---|
| Column | Description |
| 01 | Line Number of Element Data |
| 03-07 | Satellite Number |
| 09-16 | Inclination [Degrees] |
| 18-25 | Right Ascension of the Ascending Node [Degrees] |
| 27-33 | Eccentricity (decimal point assumed) |
| 35-42 | Argument of Perigee [Degrees] |
| 44-51 | Mean Anomaly [Degrees] |
| 53-63 | Mean Motion [Revs per day] |
| 64-68 | Revolution number at epoch [Revs] |
| 69 | Checksum (Modulo 10) |
Sources of Orbital Data
http://www.celestrak.com/NORAD/elements/
Satellite Lunar and Solar Transits
A lunar or solar satellite transit, is when a satellite passes across, the moon are sun.
Satellite Lunar Transits I have seen
| Date | Time | Satellite Name | Norad Number |
| Aug 13, 2001 | 4:23 am EDT ( 8:23 UT ) | Cosmos 292 Rocket | 04071 |
| Sept 14, 2001 | 4:16 am EDT ( 8:16 UT ) | ISS ( International Space Station ) | 25544 |
How to predicted them
Software
Prediction Services
http://iss-transit.sourceforge.net/TransitAlert.html ( Only the International Space Station at the moment )
Seeing two Satellite's in the sky together
In order to see two satellites near each other for a length of time, they need to have almost the same type of orbit.
Depending on the orbital height ( how far the orbit above the earth ), and inclination and other values will effect how close the appear to each other, and how long they stay near each other
One's you can see with just your eye, when the conditions are right.
SL-16 R/B 1 19120U 88039B 04294.71145574 +.00000028 +00000-0 +36512-4 0 09995 2 19120 071.0190 006.1179 0021135 069.4031 290.9349 14.18477155850756 SL-16 R/B 1 23705U 95058B 04294.68544685 -.00000246 00000-0 -10296-3 0 1761 2 23705 71.0217 4.1899 0012140 151.3209 208.8576 14.14779783463344
SL-16 R/B 1 16182U 85097B 04294.87668426 .00000339 00000-0 19660-3 0 5607 2 16182 71.0001 9.7763 0009562 272.3640 87.6388 14.15863346981893 SL-16 R/B 1 19650U 88102B 04294.82499119 +.00000210 +00000-0 +13178-3 0 05815 2 19650 070.9982 011.6223 0013290 008.8789 351.2566 14.15447782821864
SL-16 R/B 1 22220U 92076B 04294.92421489 -.00000277 +00000-0 -11625-3 0 06263 2 22220 070.9974 065.3267 0011595 120.8393 239.3872 14.16026972616366 SL-16 R/B 1 24298U 96051B 04294.89311936 -.00000048 00000-0 00000+0 0 8592 2 24298 70.9070 68.0966 0018637 242.1734 117.7498 14.12439743419158
SL-16 R/B 1 22566U 93016B 04294.79531799 -.00000285 00000-0 -12373-3 0 5351 2 22566 71.0049 45.9149 0011171 312.9711 47.0485 14.14574566597531 SL-16 R/B 1 28353U 04021B 04294.85462659 +.00000292 +00000-0 +17894-3 0 00932 2 28353 070.9982 048.7771 0004396 359.2918 000.8197 14.13840994018772
ENVISAT 1 27386U 02009A 04294.77475823 .00000068 00000-0 41448-4 0 8199 2 27386 98.5502 359.6085 0001111 94.4161 265.7152 14.32247563138098 ARIANE 5 R/B 1 27387U 02009B 04294.69972362 +.00000045 +00000-0 +30706-4 0 03680 2 27387 098.4163 356.0548 0031849 283.9922 075.7714 14.35268432138361
IDEFIX/ARIANE 42P 1 27422U 02021B 04294.71161889 +.00000054 +00000-0 +39146-4 0 07198 2 27422 098.6462 014.5158 0013070 163.5624 196.5995 14.28191483128541 H-2A R/B 1 27601U 02056E 04294.77346780 +.00000080 +00000-0 +46495-4 0 03017 2 27601 098.6646 013.5853 0072491 240.4616 118.9322 14.30432378096745