Augmentation to Ensure a Successful ATOMMS Demonstration and Evaluation

该项目涉及一种新的主动肢体探测方法的设计、开发和集成，该方法模仿成功的全球定位系统(GPS)无线电掩星(RO)探测技术。不同的是，新方法不受限制地使用专门为GPS应用分配的射频源。取而代之的是，微波中的源频率被选择为相对接近大气吸收线，以便最大限度地检测单一大气成分，如水蒸气。发送者和接收者都在这些频率上工作。其操作概念是低地球轨道(LEO)卫星平台同时飞行发射器和接收器，每个平台都相互掩蔽。该项目被称为主动温度、臭氧和水分微波光谱仪(ATOMMS)。从理论上讲，ATOMMS将把对流层、中层大气水汽和中层臭氧廓线降至1-5%，温度为0.5K，位势高度为10-20m，垂直分辨率均为~200m，在晴朗和多云空气中都是如此。通过平均化，这一性能将显著提高。ATOMMS是自校准的，它消除了长期漂移。该项目的成功是向基于空间的LEO ATOMMS测量迈出的必要一步。首席调查员(PI)正在修改他早期的ATOMMS设计，将高频音调从2个增加到4个，升级仪器电子设备，并对检索系统进行相应的更改。这些升级将提供隔离、量化和减轻最近确认的几个关键误差源所需的信息。有了4个高频段音调，PI将能够调查并有望解释首次测量演示中可能出现的任何差异和意外。具体地说，4个高频带音调将提供以下信息：(I)隔离和减少由于虚折射率和真实折射率中的湍流波动引起的幅度闪烁，(Ii)仅使用两个音调来量化和减少未完全去除冰云散射后留下的残留偏差，以及(Iii)量化光谱学中的误差，否则可能限制ATOMMS导出的轮廓的准确性。此外，4个高频段音调将增加获得有用测量的可能性，即使一个音调在飞行中失败，并允许PI演示N2O和H3NO的剖面以及水蒸气的18O/16O同位素比率。如果没有从飞机到飞机演示的四个高频段数据通道的信息，PI将无法量化几个关键错误，从而导致对ATOMMS的评估不完整，其最终性能也不确定。ATOMMS观测将满足大气、气候和地球航天科学家的关键需求，为他们的研究提供新的全球、高垂直分辨率、高度稳定和准确的数据来源。这些观测将为飞行任务机构提供天气和化学天气预报服务，并将成为国际全球气候观测系统(GCOS)的关键要素。在教育和培训方面，包括国际和平研究所在内的几名初级科学家将帮助开展这项研究。

This project involves the design, development and integration of a new active limb sounding method modeled after the successful Global Positioning System (GPS) Radio Occultation (RO) sounding technique. The difference is that the new method is not constrained to operate with radio frequency sources specifically allocated for GPS applications. Instead, source frequencies in the microwave are chosen relatively close to atmospheric absorption lines in order to maximize detection of single atmospheric constituents, such as water vapor. Both sender and receiver operate on those frequencies. The operational concept is low Earth orbiting (LEO) satellite platforms flying both transmitter and receiver, each occulting one another. The project is called The Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS). In theory, ATOMMS will profile tropospheric and middle atmosphere water vapor and middle atmosphere ozone to 1-5%, temperature to 0.5K, and geopotential heights to 10-20 m, all with ~200 m vertical resolution, in both clear and cloudy air. This performance will improve significantly with averaging. ATOMMS is self-calibrating, which eliminates long-term drift. The success of this project is a necessary step toward space-based LEO ATOMMS measurements. The Principal Investigator (PI) is modifying his earlier ATOMMS design by increasing the number of high band tones from 2 to 4, upgrading the instrument electronics and making commensurate changes in the retrieval system. These upgrades will provide the information needed to isolate, quantify and mitigate several recently recognized key sources of error. With 4 high band tones, the PI will be able to investigate and hopefully explain any discrepancies and surprises that are to be expected in a first time measurement demonstration such as this. Specifically, the 4 high band tones will provide the information to (i) isolate and reduce amplitude scintillations due to turbulent fluctuations in the imaginary and real refractivity, (ii) quantify and reduce residual biases left after incomplete removal of ice cloud scattering using only two tones, and (iii) quantify errors in spectroscopy that are otherwise likely to limit the accuracy of ATOMMS-derived profiles. In addition, 4 high band tones will increase the likelihood of acquiring useful measurements even if a tone were to fail during a flight and allow the PI to demonstrate profiling N2O and H3NO and the 18O/16O isotopic ratio of water vapor. Without the information from four channels of high band data in the aircraft to aircraft demonstrations the PI would be unable to quantify several critical errors leaving the assessment of ATOMMS incomplete and its ultimate performance uncertain. ATOMMS observations will fulfill crucial needs for atmospheric, climate and geospace scientists, by providing new sources of global, high vertical resolution, highly stable and accurate data important to their research. The observations will serve mission agencies in weather and chemical weather forecasting and would be a key element in the international Global Climate Observing System (GCOS). In regard to education and training, several junior scientists, including the co-PI, will help to conduct this research.