Shuttle derived atmosphere

The shuttle descends along a rather shallow path, thus providing some information on the horizontal structure of the atmosphere. Small scale structures were suggested (shears, potholes). The best estimates of the shuttle drag coefficient and projected areas are used to go from accelerometer data to density through the use of BET's (Best Estimated Trajectories). Data are from the IMU's (Inertial Measurement Unit) and the HiRAP (High Resolution Accelerometer Package).