  We use an airborne pulsed integrated path differential absorption lidar to
make spectroscopic measurements of the pressure-induced line broadening and
line center shift of atmospheric CO2 at the 1572.335 nm absorption line. We
measure the absorption lineshape in the vertical column between the aircraft
and ground. A comparison of our measured absorption lineshape to calculations
based on HITRAN shows excellent agreement with the peak optical depth accurate
to within 0.3%. Additionally, we measure changes in the line center position to
within 5.2 MHz of calculations, and the absorption linewidth to within 0.6% of
calculations.
