dsavransky
commented
6 years ago Planets are propagated to their positions at the 'current' mission time at the time of any observations. Each system is therefore at different times at the end of the simulation. The position and velocity vectors that are stored in the SurveySimulation object therefore represent the positions and velocities of the planets at the last time when they were observed (or at their initial points if never observed). Your code indexes these static arrays (sim.SimulatedUniverse.r and sim.SimulatedUniverse.v) after the simulation has ended, so the values are always the same, but during the simulation they are continuously being updated.
The DRM object encodes some values about the planetary systems at the time of their observation (the star-planet separation, angular separation, delta-mag) but not the full position/velocity states. If you need the full velocity/position states, you can do one of several things: 1) Create your own overloaded SurveySimulation implementation which also writes the position & velocity to the DRM object (easiest would be to modify the det_systemParams dictionary generated in method observation_detection 2) Just re-create the full pos/vel states based on the planets' known orbital elements and the time of observation. All the code to do this can be found in the SimulatedUniverse constructor where the position/velocities arrays are first created, and method propag_system where they are propagated in time.
Hi,
I have an important issue. To be able to do orbit reconstruction for my master's thesis, I need EXOSIMS to visit those stars multiple times, around which it has succesfully detected an exoplanet. I could solve this problem only by using a star catalogue as input which contains just a small amount of stars (so that there's enough mission time left for revisits). I am not sure whether this is the way you intended to make EXOSIMS revisiting stars. However, another problem is, that the planet's position and velocity vectors are always the same for the first and any further visit. Do you have any idea why the planets do not move forward?
I would be very thankful for any answer!
Kind regards, Katja
My code to start the simulation is:
The output looks like: