Questions tagged [quaternion]
The quaternion tag has no summary.
7 questions
4votes
1answer
78views
Calculating azimuth and elevation of a ground station in satellite coordinate frame
I have a satellite 'Sat' and Ground Station 'GS'. I'm defining elevation and azimuth with respect to satellite boresight which is always pointing at nadir. More specifically, elevation is the angle of ...
- 275
0votes
0answers
1kviews
Spacecraft attitude: rotation between ECI, LVLH, and Body frames
I'm starting to study spacecraft attitude control and I'm quite confused about the attitude representation in different frames. By reading a bunch of textbooks and papers, I understood that I can ...
- 101
2votes
1answer
727views
How to calculate initial Rotation Matrix/ Euler Angles/ Quaternion for IMU data (gyroscope and accelerometer)?
I am trying to develop a code to track vehicle using GNSS/GPS data (NMEA) and IMU data (Gyroscope x,y,z; accelerometer x,y,z) i.e. dead reckoning using kalman filter. I know there's enough literature ...
- 39
3votes
1answer
310views
Should coordinate transformations from J2000 to ITRF93 in quaternions be cyclic?
I used SPICE's pxform at an interval of epochs to determine the transformation from J2000 (inertial) to ITRF93 (Earth body-fixed) frame. Then, I converted these rotation matrices to quaternions with ...
- 63
3votes
0answers
112views
Finding reference quaternion of a satellite in orbit
How can i find the reference quaternion of a satellite after it has detumbled? I need the quaternion to be able to successfully actuate my payload, which in this case will be a hyperspectral imaging ...
4votes
2answers
653views
How should the ISS telemetry for attitude be converted to roll, pitch, and yaw?
NASA, via Lightstreamer SRL, provides four "quaternion components" for the International Space Station's current attitude. These are labelled USLAB000018–21 and described as "US Current Local Vertical ...
- 218
19votes
1answer
8kviews
What are quaternions and how are they used to represent spacecraft dynamics?
The title says it all. Quaternions are widely used to represent the orientation of a spacecraft. Why is that, and how do quaternions compare to other alternatives?
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