Been there, done that...bit of a nightmare journey though. (See the pics
on the related projects web page (University of Wales, Aberystwyth).

As for the constants/changes, most of them are in SimGear...  from off
the top of my head the following should be enough to get correctly sized
scenery for Mars - (you'll need to make the simgear changes BEFORE running 
or building TerraGear though - otherwise you'll get interesting effects
with height and terrain mapping)



  static const double a = 3394.0;       /* Radius */
  static const double f = 1.0/154.409;   /* Flattening parameter */
  static const double b = 3394.0 * (1.0-1.0/154.409); /* Minor radius */
  static const double r_0 = 3389.0;  /* Mean radius */


  static const double FP = 0.0064763064;
  static const double E = 0.99352369;
  static const double EPS = 0.11362516;
  static const double INVG = 0.8260263;


  #define SG_EARTH_RAD 3394.0
  #define SG_EQUATORIAL_RADIUS_FT 11135035
  #define SG_EQUATORIAL_RADIUS_M 3394000.00
  #define SG_EQ_RAD_SQUARE_FT 123989004451225
  #define SG_EQ_RAD_SQUARE_M 1.1519236e13

You'll also have to modify your flight model of choice (we don't have
that problem as we use the Magic carpet for our work at the moment
so there is no flight model mod).  But saying that, I have had
some success modifying Larcsim (just a couple of constants).  If you
get seg faults when firing up the flight model you may want to check that
your precision on the above values (esp radius squared and radius) are correct
as I found a division by zero problem when I didn't have enough precision.

Have fun


In message <[EMAIL PROTECTED]>, 
        Greg Long <[EMAIL PROTECTED]> writes:

> One of the main goals we would like to work on is Martian terrain.  I'm not
> sure how much of the Earth's parameters are hard coded, but I'm imagining
> it shouldn't be TOO difficult to produce Mars scenery for the sim.  I have
> done it a little bit with MS's Flight Sim, and the initial results were
> impressive - and FUN.  I'm imagining a current Martian atmosphere, as well
> as a hypothetical post-teraformed Mars.  Please feel free to read what I
> have done so far at:

* Phil Summers MEng,               * "Getting right to the       *
* Computer Science Dept            *  heart of matters...        *
* University of Wales, Aberystwyth *  It's the heart that        *
* [EMAIL PROTECTED]                 *  matters more"              *
* Tel: +44 (0)1970 621528                                        *
* Fax: +44 (0)1970 622455                                        *
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