GPM GROUND VALIDATION AIRBORNE SECOND GENERATION PRECIPITATION RADAR (APR-2) GCPEX V1

The GPM Ground Validation Airborne Second Generation Precipitation Radar (APR-2) GCPEx dataset was collected during the GPM Cold-season Precipitation Experiment (GCPEx), which occurred in Ontario, Canada during the winter season of 2011-2012. GCPEx addressed shortcomings in the GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. The Second Generation Airborne Precipitation Radar (APR-2) is a dual-frequency (13 GHz and 35 GHz), Doppler, dual-polarization radar system. It has a downward looking antenna that performs cross track scans, covering a swath that is +/- 25 degrees to each side of the aircraft path. Additional features include: simultaneous dual-frequency, matched beam operation at 13.4 and 35.6 GHz (same as GPM Dual-Frequency Precipitation Radar), simultaneous measurement of both like- and cross-polarized signals at both frequencies, Doppler operation, and real-time pulse compression (calibrated reflectivity data can be produced for large areas in the field during flight, if necessary). The APR-2 flew aboard the NASA DC-8 for the GPM Cold-season Precipitation Experiment (GCPEx) from 11 January to 25 February, 2012.

GPM 地面验证航空第二代降水雷达（APR-2）GCPEx 数据集是在 2011-2012 年冬季加拿大安大略省进行的 GPM 冷季降水实验（GCPEx）期间收集的。GCPEx 通过收集微物理特性、相关遥感观测以及降水雪的协调模型模拟，解决了 GPM 雪量检索算法的不足。第二代航空降水雷达（APR-2）是一种双频段（13 GHz 和 35 GHz）、多普勒、双极化雷达系统。它配备向下观测的天线，执行横越轨迹扫描，覆盖范围为飞机路径两侧各 ±25 度的宽度。此外，其特性还包括：在 13.4 GHz 和 35.6 GHz（与 GPM 双频段降水雷达相同）频率上同时进行双频段、匹配波束操作，同时在两种频率上同时测量类似极化和交叉极化信号，多普勒操作，以及实时脉冲压缩（如有必要，在飞行过程中可以产生适用于大面积区域的校准反射率数据）。APR-2 在 2012 年 1 月 11 日至 2 月 25 日期间搭载 NASA DC-8 飞机参与了 GPM 冷季降水实验（GCPEx）。