The high-cadence multi-object imaging (HMI) is an effective way to discover and observe celestial objects with fast temporal variation, such as: space debris, exoplanet, optical counter part of the TDI or GRB. It would be interesting to develop new observation methods for the HMI, such as: multiple telescopes observation method or ultra-wide field high resolution image reconstruction method. The simulation would provide an unique way to test these ideas and we develop a software dyskysim to make it possible. The flow chart of dyskysim is shown below.
The dyskysim has three parts: the starmap can generate a star catalog with temporal variation; the psfmap can generate a real photon map of the celestial objects and the imagemap can model the photon-electronic process and generate the observation image. The unique parts for dyskysim are:
a high-fidelity multiple-layer atmospheric turbulence phase screen model (can import real turbulence profile from measure data and generate phase screens with any power spectrum);
an all physical light propagation model from the poppy which makes simulation of the scitillation or light propagation inside the telescope possible; a
an low-level photosensor model, which can model the CCD and CMOS with different types;
a fast simulation mode, which can generate observation images with analytical PSFs (Gaussian or Moffat model);
a high-fidelity star field simulation port, which can hold the star catalog either from dyskysim , other simulation code or real observation data.
These features make dyskysim suitable to simulate the dynamical sky with very high cadence, which means we can generate wide field high cadence observation data with dyskysim.
The figures below are two simulated long exposure images generated from
dyskysim : one for sparse star field and one for crowd star field with moving targets (space debris).
Simulation results of crowd star field (left for analytical simulation result and right for Monte Carlo simulation result) from dyskysim with real and fast mode.
You can also check the simulation results with the video of crowd star field and the sparse star field.
The first version of dyskysim can be downloaded below. It follows the CC-ND licence.