CAJ | 학술논문

2013年9月发射的 FY-3C 是我国第2代极轨气象卫星的第3颗星，其上装载的微波湿温探测仪在118 GHz氧气吸收线和183 GHz 水汽吸收线设计了两组大气探测通道，在大气窗区设置了89 GHz 和150 GHz 探测通道。为保证微波湿温探测仪在轨定量应用，卫星发射前完成了地面热真空试验。该文介绍了热真空定标试验原理，并对 FY-3C 微波湿温探测仪正样产品真空试验数据进行了定量分析。数据分析结果表明：FY-3C 微波湿温探测仪正样产品15个探测通道的灵敏度均满足设计指标要求，各通道观测亮温间相对独立，定标准确度优于1．6 K，真空试验过程中微波湿温探测仪定标结果稳定。FY-3C 微波湿温探测仪发射前热真空定标特性分析结果为仪器在轨定量应用奠定了基础。
2013년9월발사적 FY-3C 시아국제2대겁궤기상위성적제3과성，기상장재적미파습온탐측의재118 GHz양기흡수선화183 GHz 수기흡수선설계료량조대기탐측통도，재대기창구설치료89 GHz 화150 GHz 탐측통도。위보증미파습온탐측의재궤정량응용，위성발사전완성료지면열진공시험。해문개소료열진공정표시험원리，병대 FY-3C 미파습온탐측의정양산품진공시험수거진행료정량분석。수거분석결과표명：FY-3C 미파습온탐측의정양산품15개탐측통도적령민도균만족설계지표요구，각통도관측량온간상대독립，정표준학도우우1．6 K，진공시험과정중미파습온탐측의정표결과은정。FY-3C 미파습온탐측의발사전열진공정표특성분석결과위의기재궤정량응용전정료기출。
The microwave humidity sounder (MWHS)is a five channel microwave radiometer in the range of 150-191 GHz onboard FY-3A and FY-3B.FY-3A and FY-3B are successfully launched in 2008 and 2010,re-spectively.The next generation of MWHS is a microwave humidity and temperature sounder.This sensor is developed to fly on the third satellite of new generation polar orbit meteorological satellite of China (FY-3C)is launched in September 2013. <br> The microwave humidity and temperature sounder has 15 channels in the range of 89 - 191 GHz. Eight temperature sounding channels with central frequency of 118.75 GHz oxygen gas line and five hu-midity sounding channels with central frequency of 183.31 GHz water vapor line.Two window channels center at 89 GHz and 150 GHz.118 GHz channel is first used to detect atmosphere on current operational satellite.Channels in the oxygen band are at around 54 GHz used by AMSU-A (advanced microwave sounding unit-A)and ATMS (advanced technology microwave sounder).Channels in the next oxygen ab-sorption band are at around 118.75 GHz,which can well detect atmosphere temperature in the lower trop-osphere.The temperature sounding channels around 118.75 GHz detect the atmosphere temperature from 900 hPa to 25 hPa.The microwave humidity and temperature sounder adds two humidity sounding chan-nels compared with MWHS that can obtain fine vertical distribution structure of atmosphere humidity. <br> In order to determine the radiometric performance and the on-orbit use of the microwave humidity and temperature sounder,an extensive test is performed before launch.The microwave humidity and tempera-ture sounder is placed in a thermal-vacuum chamber where the cold and earth targets are installed at fixed position.The instrument temperature is controlled at 5℃,15℃ and 25℃ which is expected in orbit.The temperature of earth target maintains from 95 K to 330 K and space target is controlled at 95 K.Tempera-tures of these whole targets are measured by PRT (platinum resistance thermometer)and the temperature measurement accuracy is better than 0.1 K.The test database include counts of internal blackbody,earth and cold targets are obtained by the new microwave radiometer and the temperature measured by PRT. <br> The sounder is calibrated with the thermal-vacuum chamber test method,and test data are quantita-tively analyzed.Results for noise equivalent differential temperatures of fifteen channels show that all fif-teen channel measured sensitivities meet requirements of indicators.Noise equivalent differential tempera-tures of humidity channels are all below 0.5 K which are also at the same level of indicators from ATMS. The channels around 118.75 GHz except channel 2 are all below 1 K,and that means observations from these channels used for temperature retrieval are well.Because the narrow bandwidth of channel 2,the noise equivalent differential temperature of this channel is about 1.7 K that maybe affects retrieval preci-sion.Correlations between all channels are independent.After correcting all biases,the calibration accura-cy is well below 1.12 K.Calibration results of microwave humidity and temperature sounder are stability for each channel.The radiometric characteristic analysis of all channels provide useful reference for in-orbit application of the new microwave radiometer sounder on FY-3C.