We conducted two P-band flights last week, the first being an engineering/calibration flight over Rosamond corner reflectors, and the second being a science flight over Tonzi Ranch in addition to lower altitude (30kft) Rosamond flight lines.  Preliminary assessment of the Rosamond data from the first flight showed that the radiometric calibration was quite stable. We also observed that the internal calibration signals for the H transmit channels were much improved due to the instrument rework last month, while that was not the case for the V transmit channels (needs more investigation).  With the use of the internal calibration signals from each data take, we will be able to improve the accuracy of the absolute calibration of the radar data.  We plan to conduct two additional Tonzi Ranch flights within the next week before the aircraft returns to JSC for the astronaut return mission