/spiceypy-proto

testing spiceypy libraries

Primary LanguagePython

SPICE Ephemeris Search

The goal of this prototype is to return ephemeris data for item requested.

Kernels will have to be supplied.

This is a test to try and get query data from SPICE based on a python app.

Set up Python Development Environment using virtualenv

In a development environment, make sure you have the following:

python3
pip3
virtualenv

Steps:

  1. To install virtualenv 
    pip3 install --user virtualenv
  2. Set up virtualenv venv 
    python3 -m virtualenv venv
  3. Go into the virtualenv (defaults to bash, use appropriate source file for other shells): 
    source venv/bin/activate

You can now program in python installing requirements specific to your program without affecting the entire system.

Install requirements.txt

pip3 install -r requirements.txt

SPICE Examples

  1. tkvrsn.py
  2. plot-cassini.py

tkvrsn.py

Python program that prints the version number of spice

plot-cassini.py

A little more complex examples that loads kernels and uses matplot to plot out CASSINI trajectories.

For the cassMetaK.txt file to work, it expects kernels to be in a directory structure:

... <base directory>
  |
  |_ kernels
       |
       |_ cassini

Need to download the kernels from NAIF and put them in the kernels/cassini directory: https://naif.jpl.nasa.gov/pub/naif/generic_kernels/lsk/a_old_versions/naif0009.tls https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/sclk/cas00084.tsc https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/pck/cpck05Mar2004.tpc https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/fk/release.11/cas_v37.tf https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/ck/04135_04171pc_psiv2.bc https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/spk/030201AP_SK_SM546_T45.bsp https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/ik/release.11/cas_iss_v09.ti https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/spk/020514_SE_SAT105.bsp https://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/spk/981005_PLTEPH-DE405S.bsp

Kernels are not included in github due to size limitations Git LFS latencies

plot-mars.py

... <base directory>
  |
  |_ kernels
       |
       |_ mars

Need to download the kernels: https://naif.jpl.nasa.gov/pub/naif/generic_kernels/lsk/naif0012.tls https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/satellites/mar097.bsp https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/satellites/mar097.cmt https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/satellites/mar097.inp https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/planets/de440.bsp https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/planets/de440_tech-comments.txt

Further Reading

  1. de440.bsp versus de441-partX.bsp: (Documentation)[https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/planets/de441_tech-comments.txt]

    The ephemerides DE440 and DE441 are fitted to the same data set, but DE441 assumes no damping between lunar liquid core and solid mantle, which avoids a divergence when integrated backwards in time. Therefore, DE441 is less accurate than DE440 for the current century, but covers a much longer duration of years -13,200 to +17,191, compared to DE440 covering years 1,550 to 2,650.

    For smaller file footprint, use de440.bsp

  2. MetaKernels: https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/kernel.html#Path%20Symbols%20in%20Meta-kernels

  3. Cassini Example: https://spiceypy.readthedocs.io/en/main/exampleone.html

  4. WebGeocalc: https://wgc.jpl.nasa.gov:8443/webgeocalc/#NewCalculation