Noted that while tracking the International Space Station (ISS) the position and orbit did not match that from the NASA real time tracking site. What can be done to match the actual position/orbit.
Joe Willie
ISS tracking
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Topic authorJoe Willie
ISS tracking
Question: Noted that while tracking the International Space Station (ISS) the position and orbit did not match that from the NASA real time tracking site. What can be done to match the actual position/orbit.
Joe Willie
Noted that while tracking the International Space Station (ISS) the position and orbit did not match that from the NASA real time tracking site. What can be done to match the actual position/orbit.
Joe Willie
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JackHiggins
- Posts: 1034
- Joined: 16.12.2002
- With us: 21 years 11 months
- Location: People's Republic Of Cork, Ireland
The standard ssc orbit for the ISS that comes with celestia is shockingly innacurate...
Heres what to do to get the very latest correct elements:
1. Goto http://www.celestrak.com , go to the current data page, and click ISS.
2. Copy the two lines of figures under the line saying "ISS Zarya"
It currently reads:
3. Download grant hutchinson's TLE- ssc converter (You'll find it on the addons forum)
4. Input those 2 lines into the converter
5. save the resulting output as an ssc file, into celestia's extras folder.
6. Now you should have an object orbiting the earth called "1998-067A" which is the designator for the ISS. This is what you should be tracking
Alternatively, you could just get a astronomy program which directly accepts TLE orbits... But celestia is better so dont
Heres what to do to get the very latest correct elements:
1. Goto http://www.celestrak.com , go to the current data page, and click ISS.
2. Copy the two lines of figures under the line saying "ISS Zarya"
It currently reads:
Code: Select all
1 25544U 98067A 03215.13887731 .00012972 00000-0 15807-3 0 2908
2 25544 51.6317 143.9641 0008292 81.5711 124.4334 15.60845702268338
3. Download grant hutchinson's TLE- ssc converter (You'll find it on the addons forum)
4. Input those 2 lines into the converter
5. save the resulting output as an ssc file, into celestia's extras folder.
6. Now you should have an object orbiting the earth called "1998-067A" which is the designator for the ISS. This is what you should be tracking
Alternatively, you could just get a astronomy program which directly accepts TLE orbits... But celestia is better so dont
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JackHiggins
- Posts: 1034
- Joined: 16.12.2002
- With us: 21 years 11 months
- Location: People's Republic Of Cork, Ireland
Guest wrote:Alternatively Jack...you could post the ssc for us?
Well ok so
Code: Select all
"ISS (03/08/2003)" "Sol/Earth" {
Class "spacecraft"
Mesh "iss.3ds"
Radius 0.01
EllipticalOrbit {
Epoch 2452854.63887731
Period 0.06406783
SemiMajorAxis 6763.343
Eccentricity 0.0008292
Inclination 51.6317
AscendingNode 143.9641
ArgOfPericenter 81.5711
MeanAnomaly 124.4334
}
Obliquity 51.6317
EquatorAscendingNode 143.9641
RotationOffset 126.5079
# Orientation [ ]
}But don't forget that the ISS's orbit changes regularly, it doesn't stay static forever... In other words if it's supposed to fly over on a certain night, you'll need to get updated elements that day to make sure you know when to look up...
You need to know how to do it yourself, because people won't be posting updated elements every time they change on celestrak... (which is every single day)
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HankR
Slightly off-topic, but possibly of interest to ISS observers:
A few weeks ago I did an ISS "marathon", in which I observed the ISS pass overhead on five consecutive orbits. It was fun to do, although I didn't get much sleep that night!
Five consecutive sighting opportunities seems fairly common, although I doubt that very many people have made the effort to do it. I'm unsure if six consecutive sightings is ever possible.
- Hank
A few weeks ago I did an ISS "marathon", in which I observed the ISS pass overhead on five consecutive orbits. It was fun to do, although I didn't get much sleep that night!
Five consecutive sighting opportunities seems fairly common, although I doubt that very many people have made the effort to do it. I'm unsure if six consecutive sightings is ever possible.
- Hank