I found altitude, speed and acceleration data of old mission Phoenix during EDL phase, but they are referred to Mars c.o.g. rather than to ground or to landing site:
Position and velocity (X_POSITION, Y_POSITION, Z_POSITION and associated uncertainties; X_VELOCITY, Y_VELOCITY, Z_VELOCITY and associated uncertainties) are given in an XYZ cartesian frame whose origin is at the center of mass of Mars. The +Z axis passes through the north pole and the +X axis passes through the equator at zero degrees east areocentric longitude at a specified time. The +Y axis completes a right-handed set.
How can I re-calculate the data w.r.t landing site ? (68.2368N ,234.3111E , landed 2316.903 seconds after reference time 2008-05-25T23:00:00.000). I should calculate speed and position of landing site w.r.t. Mars center at each EDL moment, but how?
Or where can I find such recalculated data?