ParticleIntegrator: Input

The input for the Integrator is located in a text file inside of the INPUT-folder. In this file, each particle is defined in a separate line with 8 tab-separated values per particle.

The first 6 values define the state vector for the particle in the coordinates of the solar system barycenter. The seventh value describes the multiplication factor and is only copied over into the output files - it has no influence on the integration itself. It describes how many actual particles one simulated particle represents. The last value defines the time of origin of the particle in spice ephemeris time (which represents Barycentric Dynamical Time (TDB), more information here).

The input file may (but doesn't have to) contain a number of comment lines at the beginning. They start with a % character. Comments among the particles or at the end are not allowed. At the end, it must contain a newline character.

We recommend using more digits than in the example below. Ideally, the full precision of the 64bit double precision floating point numbers that are used internally. This requires about 17 significant figures.

% Initial state for comet    1000095
% for particles with mass 1e-08 kg
% for separation angle   4.000000 degrees
% for all apparitions
% X (km)        Y (km)        Z (km)        Vx (km/s)   Vy (km/s)   Vz (km/s)   Multiplication Factor	et
-330911442.485  78465726.588  95706144.507  22.649      12.127      -3.095      1.415e+11              -9.4891408607e+09
-330911442.485  78465726.588  95706144.507  22.648      12.128      -3.099      1.412e+11              -9.4891408607e+09