Pulse compression is employed in phased-array Doppler weather radar to increase the detection range and improve the range resolution under the condition of low transmission power.Three aspects,including the composition of low power Doppler weather radar with planar array and pulse compression,and range and Doppler measurements coupled with linear frequency modulated waveforms,and target range measurements,are discussed in this paper.Due to the nature of the conical beams scanning,the main beam broadens as it is scanned from broadside,and the power decreases within the main beam.For accurate and efficient computation of a reflectivity estimated from the weather signal data samples,the scan angle error correction for the two dimensional arrays weather radar equation is necessary.This paper presents the derivation of a correction to the weather radar equation for use with planar phased array and pulse compression radars.It is shown that the equation is also suitable for linear array pulse compression radars.