Marinan Anne D, Cahoy Kerri L, Bishop Rebecca L, Lui Susan S, Bardeen James R, Mulligan Tamitha, Blackwell William J, Leslie R Vincent, Osaretin Idahosa, Shields Michael
Aeronautics and Astronautics Department at the Massachusetts Institute of Technology, Cambridge, Massachusetts. She is now with the Jet Propulsion Laboratory, Pasadena, California.
Aeronautics and Astronautics Department and Earth Atmospheric and Planetary Sciences Department at the Massachusetts Institute of Technology, Cambridge, Massachusetts.
IEEE J Sel Top Appl Earth Obs Remote Sens. 2016 Dec;9(12):5703-5714. doi: 10.1109/JSTARS.2016.2598798. Epub 2016 Oct 25.
The Microwave Radiometer Technology Acceleration (MiRaTA) is a 3U CubeSat mission sponsored by the NASA Earth Science Technology Office (ESTO). The science payload on MiRaTA consists of a tri-band microwave radiometer and Global Positioning System (GPS) radio occultation (GPSRO) sensor. The microwave radiometer takes measurements of all-weather temperature (V-band, 50-57 GHz), water vapor (G-band, 175-191 GHz), and cloud ice (G-band, 205 GHz) to provide observations used to improve weather forecasting. The Aerospace Corporation's GPSRO experiment, called the Compact TEC (Total Electron Content) and Atmospheric GPS Sensor (CTAGS), measures profiles of temperature and pressure in the upper troposphere/lower stratosphere (∼20 km) and electron density in the ionosphere (over 100 km). The MiRaTA mission will validate new technologies in both passive microwave radiometry and GPS radio occultation: (1) new ultra-compact and low-power technology for multi-channel and multi-band passive microwave radiometers, (2) the application of a commercial off the shelf (COTS) GPS receiver and custom patch antenna array technology to obtain neutral atmospheric GPSRO retrieval from a nanosatellite, and (3) a new approach to spaceborne microwave radiometer calibration using adjacent GPSRO measurements. In this paper, we focus on objective (3), developing operational models to meet a mission goal of 100 concurrent radiometer and GPSRO measurements, and estimating the temperature measurement precision for the CTAGS instrument based on thermal noise. Based on an analysis of thermal noise of the CTAGS instrument, the expected temperature retrieval precision is between 0.17 K and 1.4 K, which supports the improvement of radiometric calibration to 0.25 K.
微波辐射计技术加速（MiRaTA）是一项由美国国家航空航天局地球科学技术办公室（ESTO）赞助的3U立方星任务。MiRaTA上的科学有效载荷包括一个三频段微波辐射计和全球定位系统（GPS）无线电掩星（GPSRO）传感器。微波辐射计测量全天候温度（V波段，50 - 57吉赫兹）、水汽（G波段，175 - 191吉赫兹）和云冰（G波段，205吉赫兹），以提供用于改进天气预报的观测数据。美国航空航天公司的GPSRO实验，称为紧凑型总电子含量（TEC）和大气GPS传感器（CTAGS），测量对流层上部/平流层下部（约20千米）的温度和压力剖面以及电离层（超过100千米）的电子密度。MiRaTA任务将验证无源微波辐射测量和GPS无线电掩星方面的新技术：（1）用于多通道和多频段无源微波辐射计的新型超紧凑、低功耗技术；（2）应用商用现货（COTS）GPS接收机和定制贴片天线阵列技术从纳米卫星获取中性大气GPSRO反演数据；（3）一种利用相邻GPSRO测量进行星载微波辐射计校准的新方法。在本文中，我们关注目标（3），开发运行模型以实现同时进行100次辐射计和GPSRO测量的任务目标，并基于热噪声估计CTAGS仪器的温度测量精度。基于对CTAGS仪器热噪声的分析，预期的温度反演精度在0.17开尔文至1.4开尔文之间，这支持将辐射校准精度提高到0.25开尔文。
