ParticleAnalyser: Input

The input for the ParticleAnalyser is passed to the application as command-line arguments when calling it from a command window.

There are three arguments which are always require and some optional arguments. These are:

• required:

  • "--input COMETPATH" where COMETPATH is the path to the folder containing all a comet's WUs.
  • "--output OUTPUTPATH" where OUTPUTPATH is the path/file where the output particle file is stored.
  • "--time TIME" where TIME is the requested time at which particle positions will be computed. format is ephemeris time [s] (before/past J2000).

• optional:

  • "--tmin TMIN" Particles must have formed after TMIN. [seconds before/past J2000]
  • "--tmax TMAX" Particles must have formed before TMAX. [seconds before/past J2000]
  • "--mmin MMIN" Particles must have a mass equal to or higher than MMIN. [kg]
  • "--mmax MMAX" Particles must have a mass equal to or lower than MMAX. [kg]
  • "--object OBJECT_ID MAX_DISTANCE" Specify an object with a Spice-conform ID, e.g. 'EARTH' ('3') or 'ROSETTA'. Specify a distance [km] to the object within that particles must be, e.g. '150000000' (~1AU). The output will only contain particles within MAX_DISTANCE, position and velocity coordinates will be relative to that of the object. NOTE: You have to put the path of the object's kernel in kernels_spk.txt if not already included in kernels_generic.txt
  • "--intg DV_STEP N_PLANETS PLANETS_ID" Instead of using Kepler orbits from the last saving point, the particle's trajectories are numerically integrated (usally only required if Jupiter is close to the region of interest ( << 1AU). DV_STEP is the change of velocity allowed per integration step in km/s. Suggested values are between 0.1 and 2 (higher means lower accuracy). N_planets is the number of planets whose gravity is considered besides that of the Sun. PLANETS_ID contains the planets' SPICE IDs seperated by spaces. (Example: "--intg 1 2 5 3" means besides the Sun, Jupiter and Earth are considered)
  • flags:
    • "-s" sun_centred: particle positions will be converted to Sun centred coordinates before calculating Kepler orbits (not recommended, use --intg instead)
    • "-v" velocities: output in normal mode will contain velocity coordinates
    • "-n" nodes: compute particle nodes in the orbital plane of OBJECT_ID (requires --object to be set)
    • "-p" pc2-format: the output file will have .pc2 file format.

Example input (values can be double precision):

panalyser --input D:\DATABASE\1000095 --output \storeOutput\leonids1999 --time -3.8447e6 --tmin -5.3647e9 --mmax 1e-6 --object 3 5e7 -sn

Using the above input arguments PAnalyser will do the following:

• Search for work units in D:\DATABASE\1000095 (exemplary directory of TempelTuttle results).
• It looks for all particles created since TMIN (-5.3647e9 ~ 1 JAN 1830) and before TIME (-3.8447e6 ~ 18 NOV 1999) and have a mass of 1e-6 kg and less.
• It computes the nodes of all those particles, which are within a distance of 5e7 km of Earth at TIME, in the Earth's orbital plane using Sun-centred Kepler orbits.
• It saves these nodes in a binary file called "leonids1999" in a folder ".\storeOutput" using the format "-n".

Work unit check (WUcheck):

This feature looks for a comet's WU summary file and checks if any of the listed WUs is missing. The names of all the missing WUs are written to the file you specify in --output (in text format)

Usage:
panalyser --input D:\DATABASE\1000095 --output \1000095_missingWUs.txt --WUcheck