Status of Gleam Orbit simulation 6 Aug 02

Sources:

• Sean has finished the diffuse galactic modeler, which generates photons from a FITS table. We have examples computed from a model and the EGRET results, see below:

• Generation of GRB's is functional, as reported at the ICHEP conference
• Starting on using a catalog

Orbit, sun and moon positions: (Udine discussions)

In the process of incorporating code from Gino Tosti and collaborators.

Defined a tentative structure:

class OrbitInfo  {
public:

    inline std::ostream& fillStream( std::ostream& s ) const ;

    double time;     // current time: sec in elapsed mission time.
    Hep3Vector r;    // position (in km) of the spacecraft in Earth Inertial coordinates
    double lat, lon; // position of the spacecraft on the earth (deg)
    bool   saa;      // true if in SAA
    double sun_alpha, sun_delta;  // sun position in celestial coords
    double moon_alpha, moon_delta; // moon position in celestial coords

};

and an abstract tool to fill it. Perhaps this should be a TDS class.

In process of adapting code to implement it.

Agreed with Francesco and Nicola that sky positions should be encapsulated by a class, (to be named "SkyDir"). It will "hide" the data representation, and return coordinates in galactic or celestial frames. Much better way to pass sun, moon info.

Also will create an interface to a tool that will implement a "rocking" strategy. (Allowing multiple implementations, from very simple to taking slewing rate and sun position into account.)