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Questions tagged [accuracy]

The closeness of a calculation/measurement to its true value/target.

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5 votes
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Which LEO satellites have publicly available accurate position information? [duplicate]

I am working on a orbit propagation project and need accurate position information of LEO satellites. I have until now used Sentinel 3A/3B (~800 km altitude), whose ECEF coordinates I can get with a 1 ...
Frederik's user avatar
0 votes
0 answers
162 views

How to compute the pointing accuracy

I was wondering if there's an equation or somewhat intuitive way of computing the pointing accuracy of a satellite? What parameters do I need and how would I go about it?
Lez's user avatar
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0 answers
695 views

Understanding the difference between pointing knowledge, pointing accuracy and pointing stability?

In terms of specifications for satellite Attitude Determination And Control System (ADCS) hardware, my understanding is that pointing knowledge is for attitude determination, whereas pointing accuracy ...
v_space's user avatar
  • 113
6 votes
2 answers
377 views

Is it possible to create an analytical ephemeris from raw position and velocity of a Body?

I would like to have an analytical ephemeris for various bodies of the solar system (planets, natural satellites and asteroid). I have at my disposition spice kernels from which i can extract position ...
JoeDalton's user avatar
2 votes
1 answer
97 views

Significance of measure of dispersion in Orbit determination output

I am trying to understand the significance of specifying dispersion measure of 3 sigma or ½ sigma along with Orbit determination output. I am assuming a Space Craft in LEO sun-synchronous orbit of ...
Soumajit's user avatar
  • 279
0 votes
1 answer
650 views

What is the difference between Quartz Clock and Atomic Clock?

I want to know why an atomic clock is more accurate than a quartz one? I understand that the atomic clock can give time to the nanosecond, say it is 10:30:24.123456789. If we have 1GHz quartz clock, ...
Yahya Aouled Amer's user avatar
3 votes
1 answer
52 views

generated error terms for positioning based on a pre defined target accuracy level

I would like to ask a question about accuracy level and precise point positioning or PPP. I'd like to design a system such that when the desired accuracy level is provided as an input, the ...
user42663's user avatar
1 vote
1 answer
596 views

Pointing accuracy and relevant manoeuvers CUBESAT

How do you calculate or determine the pointng accuracy of your CUBESAT in sunlit-part and eclipse-part modes? Also how do you determine the maximum roll/pitch/yaw angles and slew rate required in ...
Andrea's user avatar
  • 33
7 votes
1 answer
1k views

Orbital insertion accuracy for SpaceX payloads

What is the orbital insertion accuracy of SpaceX for positioning its payload (for example satellites)? How close do they get to the requested or target orbital parameters? I tried to research this on ...
Åke's user avatar
  • 71
2 votes
0 answers
161 views

How presise could 2 satellites "thread the needle" in orbit?

I have a question about using a magnetic field to propel 2 satellites off each other while traveling in opposite directions on the same orbital plain to intersect either 2:1 or 1:1 on each orbit ...
Muze's user avatar
  • 1
4 votes
0 answers
1k views

TLE/SGP4 state vector accuracy assessment

I’m using the Planet Labs state vectors downloadable from http://ephemerides.planet-labs.com/planet.states or http://ephemerides.planet-labs.com/planet_YYYYMMDD.states to assess the TLEs/SGP4 accuracy ...
Cristiano's user avatar
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2 votes
1 answer
259 views

how "off" (as a percentage) would an attempt at geostationary orbit need to be (in either distance or speed) for a satellite to fall

how "off" (as a percentage) would an attempt at geostationary orbit need to be (in either distance or speed) for a satellite to fall to earth in 100, 1000 or 10,000 years? (assumes initial setup only,...
Rob Klassen's user avatar
4 votes
2 answers
2k views

How does a cell phone GPS receiver work without an onboard atomic clock [duplicate]

This question and its answers explain the basic theory behind GPS. I particularly like the second answer by @jah138. Using jah138's notation, GPS satellites provide extremely accurate $x_i$, $y_i$, ...
chessofnerd's user avatar
5 votes
1 answer
445 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 ...
Soumajit's user avatar
  • 279
12 votes
1 answer
1k views

How does the landing accuracy of Dragon (under parachutes) compare to Soyuz?

The Dragon capsule landed yesterday, and I saw this picture of it: Historically, capsules had a rather large uncertainty when landing, especially with parachutes. This picture was obviously taken ...
PearsonArtPhoto's user avatar
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2 votes
2 answers
2k views

Which has greater accuracy? Minuteman ICBM or Falcon 9 first stage?

The really fun part about watching SpaceX land their first stage on either their ASDS Barge (JRTI or OCISLY) or Landing Zone 1 on land, is they drew a nice target on the surface. There is a literal ...
geoffc's user avatar
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