User Documentation

Initialising satkit

To be able to initialise satkit, Orekit and Java Virtual Machine should be initialised and the Orekit Data File (containing Earth Orientation Parameters etc.) should be loaded. If the Orekit Data File is already present, a single line with a path to this file is adequate:

init_satkit(Path("..", "data", "orekit-data", "orekit-data-master.zip"))

However, if the data file does not exist, the download_data_file should be set to True. Then the file path becomes the destination file path for the data file.

init_satkit(Path("..", "data", "orekit-data", "orekit-data-master.zip"), download_data_file=True)

Note

After downloading the file, the download_data_file should be set to False (or deleted altogether, as it is the default setting). The archive files are not updated very frequently, and downloading the file every day will not make any difference.

If the latest files are needed for the analysis, the websites for these files can be found in the shell script provided by Orekit.

The user can also search for a number of directories for the file through this init_satkit() method.

init_satkit(Path("..", "data", "orekit-data", "orekit-data-master.zip"), other_path_dir_1, other_path_dir_2)

The search is conducted first in the main path, then inserting the other alternate path directories:

• Nominal path: current working dir + filepath

• Alternate paths:

  • current working dir + other_path_dir_1 + filepath

  • current working dir + other_path_dir_2 + filepath

  • …

Orbits and Trajectories

• Working with Orbital Elements
  • Introduction to Keplerian Orbital Elements
  • Mean vs Osculating Elements
  • Utilities to Compute Orbit Related Parameters
• Representing Orbits with Two-Line Elements (TLEs)
  • Introduction to TLEs
  • Components of a TLE
  • Initialising the TLEs
  • Common TLE Repositories
• Other Orbit Utilities
  • Ephemeris Propagator Generator
• Working with Multiple TLEs
  • Lists of Mixed TLEs: TleStorage
  • Extracting Specific Data from the Lists: Filtering
  • Lists of TLEs of the Same Satellite: TleTimeSeries
• Finding Events and Intervals
  • Introduction
  • Finding Ground Events and Intervals
  • Finding Satellite Events and Intervals

Working with Time and Intervals

• AbsoluteDate with Benefits: AbsoluteDateExt
  • Time Units Support
  • Adding and Subtracting Time
  • Sorting Time Objects
• Time Intervals and Time Interval Lists
  • Introduction
  • Using the Basic TimeInterval Class
  • List of time intervals: The TimeIntervalList Class