Definition and Preliminary Design of the Laser Atmospheric Wind Sounder (LAWS) Phase 1. Volume 1: Executive Summary

The laser atmospheric wind sounder (LAWS) is a facility instrument of the Earth Observing System (EOS) and is the culmination of over 20 years of effort in the field of laser Doppler wind sensing. LAWS will by the first instrument to fly in space with the capability of providing global-scale tropospheric wind profiles at high spatial resolutions. Global-scale wind profiles are necessary for: (1) more accurate diagnostics of large-scale circulation and climate dynamics; (2) improved numerical weather prediction; (3) improved understanding of mesoscale systems; (4) improved understanding of global biogeochemical and hydrologic cycles. The objective of phase 1 of the LAWS study was to evaluate competing concepts and develop a baseline configuration for the LAWS instrument. The first phase of the study consisted of identifying realistic concepts for LAWS and analyzing them in sufficient detail to be able to choose the most promising one for the LAWS application. System configurations were then developed for the chosen concept. The concept and subsequent configuration were to be compatible with two prospective platforms: the Japanese polar orbiting platform (JPOP) and the Space Station Freedom (as an attached payload). After an objective and comprehensive concept selection process, a heterodyne detection Doppler lidar using a CO2 laser transmitter operating at 9.1 microns over a 2.1 micron system with a solid state laser was chosen. The CO2 lidar concept was then analyzed in detail to arrive at a configuration for the instrument and its major subsystems. A configuration for LAWS was arrived at which meets the performance requirements, and this design is presented

Forecasting Evaluation of WindSat in the Coastal Environment

WindSat has demonstrated that measurements from polarimetric space-based microwave radiometers can be used to retrieve global ocean surface vector winds. Since the date of launch in 2003, substantial incremental improvements have been made to WindSat data processing, calibration, and retrieval algorithms. The retrievals now have higher resolution, improved wind vector ambiguity removal, and enhanced capability to represent high winds. Utilization of WindSat retrievals (wind vectors, total precipitable water, rainrate and sea surface temperature) will be demonstrated in the context of operational weather forecasting applications, especially the monitoring of topographically-forced winds. Examples will be presented from various parts of the world, including inland seas, midlatitude oceans, the tropics, and the United States. We will illustrate retrievals in extreme high- and extreme low-wind regimes, both of which can be problematic. Rain contamination will be addressed. We will include a comparison of WindSat vector maps to corresponding maps from the QuikScat scatterometer. We will discuss how near-realtime data from WindSat is being transitioned to specific offices within the National Weather Service

Pemetaan Potensi Energi Angin Di Perairan Indonesia Berdasarkan Data Satelit QuikScat Dan WindSat

There were two kinds of monsoon winds in Indonesia. They are the east and the west monsoon winds. Both of them blow alternately in a year through the Indonesian territory. The velocity and energy of monsoon winds in Indonesian territorial sea were mapped by using MatLab program. The velocity and energy data were obtained by using QuikSCAT satellite from January 1999 until December 2009, meanwhile WindSat from January 2004 until December 2014. The results show that high energy of monsoon winds start from Indian oceans until Nusa Tenggara sea, then from Arafuru sea to Banda sea, Java sea, Karimata strait and the southern region of south Sulawesi

Creating a Consistent Oceanic Multi-decadal Intercalibrated TMI-GMI Constellation Data Record

The Tropical Rainfall Measuring Mission (TRMM), launched in late November 1997 into a low earth orbit, produced the longest microwave radiometric data time series of 17-plus years from the TRMM Microwave Imager (TMI). The Global Precipitation Measuring (GPM) mission is the follow-on to TRMM, designed to provide data continuity and advance precipitation measurement capabilities. The GPM Microwave Imager (GMI) performs as a brightness temperature (Tb) calibration standard for the intersatellite radiometric calibration (XCAL) for the other constellation members; and before GPM was launched, TMI was the XCAL standard. This dissertation aims at creating a consistent oceanic multi-decadal Tb data record that ensures an undeviating long-term precipitation record covering TRMM-GPM eras. As TMI and GMI share only a 13-month common operational period, the U.S. Naval Research Laboratory\u27s WindSat radiometer, launched in 2003 and continuing today provides the calibration bridge between the two. TMI/WindSat XCAL for their \u3e 9 years\u27 period, and WindSat/GMI XCAL for one year are performed using a robust technique developed by the Central Florida Remote Sensing Lab, named CFRSL XCAL Algorithm, to estimate the Tb bias of one relative to the other. The 3-way XCAL of GMI/TMI/WindSat for their joint overlap period is performed using an extended CFRSL XCAL algorithm. Thus, a multi-decadal oceanic Tb dataset is created. Moreover, an important feature of this dataset is a quantitative estimate of the Tb uncertainty derived from a generic Uncertainty Quantification Model (UQM). In the UQM, various sources contributing to the Tb bias are identified systematically. Next, methods for quantifying uncertainties from these sources are developed and applied individually. Finally, the resulting independent uncertainties are combined into a single overall uncertainty to be associated with the Tb bias on a channel basis. This dissertation work is remarkably important because it provides the science community with a consistent oceanic multi-decadal Tb data record, and also allows the science community to better understand the uncertainty in precipitation products based upon the Tb uncertainties provided

Inter-satellite Microwave Radiometer Calibration

The removal of systematic brightness temperature (Tb) biases is necessary when producing decadal passive microwave data sets for weather and climate research. It is crucial to achieve Tb measurement consistency among all satellites in a constellation as well as to maintain sustained calibration accuracy over the lifetime of each satellite sensor. In-orbit inter-satellite radiometric calibration techniques provide a long term, group-wise solution; however, since radiometers operate at different frequencies and viewing angles, Tb normalizations are made before making intermediate comparisons of their near-simultaneous measurements. In this dissertation, a new approach is investigated to perform these normalizations from one satellite\u27s measurements to another. It uses Taylor\u27s series expansion around a source frequency to predict Tb of a desired frequency. The relationship between Tb\u27s and frequencies are derived from simulations using an oceanic Radiative Transfer Model (RTM) over a wide variety of environmental conditions. The original RTM is built on oceanic radiative transfer theory. Refinements are made to the model by modifying and tuning algorithms for calculating sea surface emission, atmospheric emission and attenuations. Validations were performed with collocated WindSat measurements. This radiometric calibration approach is applied to establish an absolute brightness temperature reference using near-simultaneous pair-wise comparisons between a non-sun synchronous radiometer and two sun-synchronous polar-orbiting radiometers: the Tropical Rain Measurement Mission (TRMM) Microwave Imager (TMI), WindSat (on Coriolis) and Advanced Microwave Scanning Radiometer (AMSR) on Advanced Earth Observing System -II (ADEOSII), respectively. Collocated measurements between WindSat and TMI as well as between AMSR and TMI, within selected 10 weeks in 2003 for each pair, are collected, filtered and applied in the cross calibration. AMSR is calibrated to WindSat using TMI as a transfer standard. Accuracy prediction and error source analysis are discussed along with calibration results. This inter-satellite radiometric calibration approach provides technical support for NASA\u27s Global Precipitation Mission which relies on a constellation of cooperative satellites with a variety of microwave radiometers to make global rainfall measurements

The impact of land surface temperature on soil moisture anomaly detection from passive microwave observations

For several years passive microwave observations have been used to retrieve soil moisture from the Earth's surface. Low frequency observations have the most sensitivity to soil moisture, therefore the current Soil Moisture and Ocean Salinity (SMOS) and future Soil Moisture Active and Passive (SMAP) satellite missions observe the Earth's surface in the L-band frequency. In the past, several satellite sensors such as the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and WindSat have been used to retrieve surface soil moisture using multi-channel observations obtained at higher microwave frequencies. While AMSR-E and WindSat lack an L-band channel, they are able to leverage multi-channel microwave observations to estimate additional land surface parameters. In particular, the availability of Ka-band observations allows AMSR-E and WindSat to obtain coincident surface temperature estimates required for the retrieval of surface soil moisture. In contrast, SMOS and SMAP carry only a single frequency radiometer and therefore lack an instrument suited to estimate the physical temperature of the Earth. Instead, soil moisture algorithms from these new generation satellites rely on ancillary sources of surface temperature (e.g. re-analysis or near real time data from weather prediction centres). A consequence of relying on such ancillary data is the need for temporal and spatial interpolation, which may introduce uncertainties. Here, two newly-developed, large-scale soil moisture evaluation techniques, the triple collocation (TC) approach and the <i>R</i><sub>value</sub> data assimilation approach, are applied to quantify the global-scale impact of replacing Ka-band based surface temperature retrievals with Modern Era Retrospective-analysis for Research and Applications (MERRA) surface temperature output on the accuracy of WindSat and AMSR-E based surface soil moisture retrievals. Results demonstrate that under sparsely vegetated conditions, the use of MERRA land surface temperature instead of Ka-band radiometric land surface temperature leads to a relative decrease in skill (on average 9.7%) of soil moisture anomaly estimates. However the situation is reversed for highly vegetated conditions where soil moisture anomaly estimates show a relative increase in skill (on average 13.7%) when using MERRA land surface temperature. In addition, a pre-processing technique to shift phase of the modelled surface temperature is shown to generally enhance the value of MERRA surface temperature estimates for soil moisture retrieval. Finally, a very high correlation (<i>R</i><sup>2</sup> = 0.95) and consistency between the two evaluation techniques lends further credibility to the obtained results

Global Microwave Imager (GMI) Spin Mechanism Assembly Design, Development, and Performance Test Results

The GMI Spin Mechanism Assembly (SMA) is a precision bearing and power transfer drive assembly mechanism that supports and spins the Global Microwave Imager (GMI) instrument at a constant rate of 32 rpm continuously for the 3 year plus mission life. The GMI instrument will fly on the core Global Precipitation Measurement (GPM) spacecraft and will be used to make calibrated radiometric measurements at multiple microwave frequencies and polarizations. The GPM mission is an international effort managed by the National Aeronautics and Space Administration (NASA) to improve climate, weather, and hydro-meteorological predictions through more accurate and frequent precipitation measurements [1]. Ball Aerospace and Technologies Corporation (BATC) was selected by NASA Goddard Space Flight Center (GSFC) to design, build, and test the GMI instrument. The SMA design has to meet a challenging set of requirements and is based on BATC space mechanisms heritage and lessons learned design changes made to the WindSat BAPTA mechanism that is currently operating on-orbit and has recently surpassed 8 years of Flight operation

Adaptability of a Catalog Spacecraft Bus to Diverse Science Missions

Over the past decade, the concept of using “offthe- shelf” Spacecraft (SC) buses for space science and earth science missions has become widespread. A “common bus” design approach has been used for Geosynchronous (GEO) communications satellites since the early 1970’s. The success of using common bus designs for the manufacture of GEO communications satellites is due to the commonality of mission requirements and orbit geometry. Science missions, on the other hand, each have unique mission and instrument payload requirements that can vary widely, encompassing orbit geometry, instrument type and configuration, science target, SC attitude, operations concept, and launch scenario. One of the most visible and successful implementations of “off-the-shelf” SC for science applications is the NASA Goddard Space Flight Center (GSFC) Rapid Spacecraft Development Office (RSDO) catalog, first released in 1997. In the current catalog (Rapid II), there are twenty-three different SC buses manufactured by eight aerospace companies. This paper provides a case study describing the adaptation of Spectrum Astro’s SA-200HP (High Performance) RSDO catalog SC bus to two very different Low Earth Orbiting (LEO) science missions, Coriolis and Swift, which were both procured via the RSDO. Coriolis is a Department-of-Defense-sponsored sunsynchronous earth observation satellite whose primary instrument, WindSat, is designed to precisely measure the ocean surface wind vector. Swift is a low inclination NASA Medium Explorer (MIDEX) mission to detect and characterize Gamma Ray Bursts (GRBs). The Swift Observatory carries three separate telescopes. In addition to describing how the catalog SC bus was applied to these missions, this paper discusses the unique features and benefits of the catalog bus approach to both the procuring agency and the industry bus provider. Misconceptions associated with the use of the catalog bus approach are also discussed

Research of Retrieving Sea Surface Wind Vectors Based on Sentinel-1A Satellite SAR Images

海面风场是海气交互界面的重要物理参数，与海洋中绝大多数的海水运动密切相关。海面风场还是海气相互作用的重要媒介，调节了海水和大气之间的物质以及能量输送，对全球气候调节也有着十分重要的作用。 船舶、浮标等观测手段花费高昂，加上海洋面积巨大，可获得的现场海面风场数据十分有限，很难满足大面积海面风场的观测需求。日益发展的卫星遥感技术，为大面积观测风场提供了可能，微波散射计已经成为大面积获取全球海面风场的最重要遥感手段之一，不过微波散射计的空间分辨率通常为25-50km，难以满足对高分辨风场的需求。相比于散射计或辐射计，合成孔径雷达(SAR)同样具有全天时、全天候观测海洋的能力，同时其通过距离向的脉冲...Ocean surface wind field is an important parameter of ocean-air interface, it is related with most of the seawater movements. Surface wind is also the medium of ocean-air interaction, which may adjust the matter and energy transformation between ocean and air. So it is important for the global climate change. Traditional wind measurements using ships or buoys cost a lot. And the wind data is too ...学位：理学硕士院系专业：海洋与地球学院_物理海洋学学号：2232013115135

Behavior of multitemporal and multisensor passive microwave indices in Southern Hemisphere ecosystems

©2014. American Geophysical Union. All Rights Reserved. This study focused on the time series analysis of passive microwave and optical satellite data collected from six Southern Hemisphere ecosystems in Australia and Argentina. The selected ecosystems represent a wide range of land cover types, including deciduous open forest, temperate forest, tropical and semiarid savannas, and grasslands. We used two microwave indices, the frequency index (FI) and polarization index (PI), to assess the relative contributions of soil and vegetation properties (moisture and structure) to the observations. Optical-based satellite vegetation products from the Moderate Resolution Imaging Spectroradiometer were also included to aid in the analysis. We studied the X and Ka bands of the Advanced Microwave Scanning Radiometer-EOS and Wind Satellite, resulting in up to four observations per day (1:30, 6:00, 13:30, and 18:00-h). Both the seasonal and hourly variations of each of the indices were examined. Environmental drivers (precipitation and temperature) and eddy covariance measurements (gross ecosystem productivity and latent energy) were also analyzed. It was found that in moderately dense forests, FI was dependent on canopy properties (leaf area index and vegetation moisture). In tropical woody savannas, a significant regression (R2) was found between FI and PI with precipitation (R2->-0.5) and soil moisture (R2->-0.6). In the areas of semiarid savanna and grassland ecosystems, FI variations found to be significantly related to soil moisture (R2->-0.7) and evapotranspiration (R2->-0.5), while PI varied with vegetation phenology. Significant differences (p-<-0.01) were found among FI values calculated at the four local times. Key Points Passive microwave indices can be used to estimate vegetation moisture Microwave observations were supported by flux data Passive microwave indices could be used to estimate evapotranspiratio