Using TLE data to determine satellite orbit (2)-SGP4 model implementation

1, the Tle Rail report:

Next, the significance of the contents of the Tle Rail report is as follows:

2. SGP4 Model:

The SGP4/SDP4 model developed by NORAD is needed for the calculation of satellite orbits in the tle orbit, and the SGP4 model was developed by Ken Cranford in 1970 for the Near Earth satellite, which is a broad solution to Lane and Cranford (1969). Analysis of the simplification of the theory, these models need to take into account the Earth's non-spherical gravity, sun and moon gravity, solar radiation pressure and atmospheric resistance and other perturbation effects. SGP4 (SimplifiedGeneral perturba tions) simplifies conventional perturbation models and can be applied to near-Earth objects with orbital periods of less than 225 minutes. SDP4 (Simplified Deep space perturbations) is a simplified space perturbation model that is applied to objects away from the earth or with orbital periods greater than 225 minutes. If the T-L-E orbital is used as the S-G P 4 model, the space target with a orbital period of less than 225 points can be predicted successfully, and the position and velocity of the target object at any time is solved.

PS: If you are interested in the specific algorithm of the SGP4 model, you can consult the relevant data.

3, the SGP4 model implementation:

NORAD published the implementation of the Fortran version, after many languages have implemented this algorithm, such as C + +, C # and MATLAB, this article uses JavaScript (refer to open source project Https://github.com/koansys/isat ), the author uses JavaScript to implement the SGP4 algorithm, if the specific implementation details are not interested in children's shoes can be directly referenced.

PS: This project is very helpful for me to make satellite orbit visualization, and give the author a picture to make an advertisement.

Reference documents:

1, based on SGP4 model of satellite orbit calculation, Shunninghui and so on.

2, using long-term tle data to determine the status of the geostationary orbit satellite, Wu Gong.

3,http://science.nasa.gov/iSat/

Using TLE data to determine satellite orbit (2)-SGP4 model implementation