Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [orbit-determination]

Measurement and estimation of satellite orbits.

5
votes
2answers
174 views

Is it possible for amateurs to determine the orbit of satellites

Maybe some people urge this is a DIY site question but i thought here is the proper place to ask this question. Is it possible for amateurs like students with commercial and available equipment like ...
3
votes
2answers
118 views

Onboard propagator in satellites SGP or J2

The Earth orbit propagator SGP4 (simplified general perturbation) was developed by NORAD to allow users to generate short-term prediction of satellite positions using two line element sets (TLEs) ...
1
vote
0answers
62 views

What is optimum data interval algorithm for Orbit Determination?

I am trying to find Optimum data interval algorithm for orbit determination. Because in Leo, Geo orbit updates the measurement data can be different so that I want to implement an optimum data ...
3
votes
2answers
145 views

Can the TLE epoch be listed as in the future? How?

Can the epoch time of a TLE be in the future? Context: ISS TLE from Heavens Above 1 25544U 98067A 18193.60071450 .00016717 00000-0 10270-3 0 9013 2 25544 51.6401 252.0472 0003848 304.4303 ...
5
votes
0answers
166 views

Outlier detection algorithm for orbit determination, how do different ones compare?

I have been reading about outlier detection algorithm for improving determinations based on realistic data. Outlier exclusion is an important tool in any analysis of realistic noisy data. There are ...
5
votes
2answers
149 views

Why are Keplerian elements used in TLEs instead of Cartesian state vectors?

Propagating a state vector seems easier, you just account for the gravity, change the velocity and update the position. It also allows to easily apply perturbations, etc. Additionally, the ...
4
votes
1answer
168 views

Can I convert from TEME to Keplerian orbital parameters?

I'm a MSC student in computer science. For my thesis I'm using SGP4 tool to propagate a LEO satellite. If I have understood rightly, the SPG4 returns the two state vectors r and v in TEME format. (...
4
votes
2answers
161 views

How do you compare a simulation with a fitted orbit?

I am very confused with regards the simulation and fitting of satellite orbits. For example, how does one compare the results of a numerically integrated force model with an orbit that has been ...
15
votes
2answers
829 views

What was the globe instrument in Vostok 1?

This image was attached to the Wikipedia article on Vostok 1 with a perfunctory caption "Part of the Vostok 1 instrument panel". I'm interested in the globe in the center. What is the name of this ...
2
votes
2answers
228 views

Spacecraft position determination

As I understand tone ranging is one of the technique used to determine satellite range from the earth station. In this case the ...
4
votes
1answer
322 views

How does the Orbit Determination Accuracy depend on the number of measurements?

How does the number of observations of spacecraft position and velocity affect the orbit determination accuracy? Suppose in one case we have 1000 instances of position and velocity measurements with a ...
4
votes
2answers
351 views

Can Keplerian elements from TLEs be used without SGP?

Are orbital elements in TLEs valid at the epoch? I want to predict an orbit without SGP, but I need some initial orbital conditions.
3
votes
1answer
281 views

How is real position of probes orbiting other planets measured?

I imagine that measuring real positions and orbital elements of satellites orbiting other planets after they perform braking maneuver to get to their final orbit must be rather difficult. Especially ...
11
votes
1answer
241 views

Tracking Arc and Time for Precise Orbit Determination

It is said that for Precise Orbit Determination (POD) of interplanetary spacecrafts, generally, during the cruise phase for aiding accurate TCM (Trajectory Correction Maneuvers) planning, long arc of ...
20
votes
2answers
2k views

How did NASA determine the distance and velocity of voyager 1?

According to Wikipedia At a distance of about 125.97 AU (1.884 × 10$^{10}$ km) from the Sun as of September 9, 2012, it is the farthest manmade object from Earth As of 2013, the probe was ...
15
votes
2answers
2k views

Will Rosetta have to adjust its orbit around Chury due to the comet's coma and tails?

ESA's Rosetta spacecraft is scheduled to orbit 67P/Churyumov–Gerasimenko after it reaches the comet by mid-2014: Rosetta's main objective is to rendezvous with, and enter orbit around, comet 67P/...
10
votes
1answer
298 views

In LEO, what is the precision of GNSS-based position compared to traditional methods?

GNSS satellites (at least the GPS ones) are in MEO, so LEO spacecraft can use GNSS for their positioning. I've read that it's quite low-cost compared to the alternatives. How does the precision of ...
16
votes
1answer
2k views

What branches of mathematics are widely used in astrodynamics?

We knew that Voyager 1 and 2 exploited the gravitational slingshot from Saturn and Jupiter back in 70s, and the trajectories were predicted by Newton's laws of motion, and this law we used a lot in ...