Advanced microwave sounding unit study for atmospheric infrared sounder

The Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU-A), and the Microwave Humidity Sounder (MHS, formerly AMSU-B) together constitute the advanced sounding system facility for the Earth Observing System (EOS). A summary of the EOS phase B activities are presented

Atmospheric infrared sounder

This report summarizes the activities of two Atmospheric Infrared Sounder (AIRS) team members during the first half of 1995. Changes to the microwave first-guess algorithm have separated processing of Advanced Microwave Sounding Unit A (AMSU-A) from AMSU-B data so that the different spatial resolutions of the two instruments may eventually be considered. Two-layer cloud simulation data was processed with this algorithm. The retrieved water vapor column densities and liquid water are compared. The information content of AIRS data was applied to AMSU temperature profile retrievals in clear and cloudy atmospheres. The significance of this study for AIRS/AMSU processing lies in the improvement attributable to spatial averaging and in the good results obtained with a very simple algorithm when all of the channels are used. Uncertainty about the availability of either a Microwave Humidity Sensor (MHS) or AMSU-B for EOS has motivated consideration of possible low-cost alternative designs for a microwave humidity sensor. One possible configuration would have two local oscillators (compared to three for MHS) at 118.75 and 183.31 GHz. Retrieval performances of the two instruments were compared in a memorandum titled 'Comparative Analysis of Alternative MHS Configurations', which is attached

Atmospheric infrared sounder

Work continued on analysis of data from the TOGA-COARE experiment. The MIT Microwave Temperature Sounder was flown on NASA's ER-2 at Wallops Island in the CAMEX experiment during September and October. The preliminary version of the 'microwave first-guess' algorithm for temperature and moisture was delivered to JPL. In the iterative minimum-variance algorithm moisture retrievals from MHS make use of the retrieved temperature profile in calculation of weighting functions and in determining the saturation moisture capacity at each level. Simulations have been run to address the question of how important the temperature profile accuracy is to the moisture retrieval

Atmospheric Infrared Sounder

The microwave 'first-guess' algorithm was run on the cloudy test simulations. Eight datasets were considered in the cloudy test, comprising approximately 360 retrievals, of which one failed to converge. Retrievals were done on the AMSU-A grid. Examination of the true profiles (provided for the A, C and D tracks) showed numerous cases of very pronounced temperature inversion layers in the troposphere which the retrieval does not have enough vertical resolution to reproduce. A typical example with an inversion layer near 700 mbar is shown in Figure 1. The inversion layers also exhibit strong vertical gradients of water vapor which are not resolved in the retrieval. (Water vapor volume density is given in g/sq cm per layer. Layer thickness is 20 mb from 200 to 400 mb, and 25 mb from 400 to 1,000 mb.) The retrievals do reproduce the overall smoothed shape of the profiles, and therefore as a first guess should be within the range of linear methods for IR retrievals using AIRS

Radio Astronomy

Contains research objectives and summary of research on seven research projects and a report on one research project.Joint Services Electronics Program (Contract DAAB07-75-C-1346)National Science Foundation (Grant AST73-05042-AO2)National Institutes of Health (Grant 5 SO5 RR07047-10)U. S. Air Force - Electronic Systems Division (Contract F19628-75-C-0122)M.I.T. Sloan Fund for Basic ResearchNational Aeronautics and Space Administration (Contract NAS5-21980)National Aeronautics and Space Administration (Contract NAS5-22485

Radio Astronomy

Contains reports on two research projects.National Aeronautics and Space Administration (Contract NAS1-10693)U. S. Air Force - Electronic Systems Division (Contract F19628-73-C-0196

Radio Astronomy

Contains research objectives and summary of research on five research projects and reports on two research projects.Joint Services Electronics Program (Contract DAAB07-74-C-0630)National Science Foundation (Grant GP-40484X)National Science Foundation (Grant MPS73-05042-A01)National Institutes of Health (Grant 1 RO1 GM20370-02)National Aeronautics and Space Administration (Contract NAS1-10693)National Aeronautics and Space Administration (Contract NAS5-21980)National Aeronautics and Space Administration (Contract NAS5-20091)U.S. Air Force - Electronic Systems Division (Contract F19628-73-C-0196

Radio Astronomy

Contains reports on one research project.National Aeronautics and Space Administration (Contract NAS5-21980

Remote Sensing and Estimation

Contains table of contents for Section 4, and reports on six research projects.MIT Lincoln Laboratory Agreement CX-19383MIT Lincoln Laboratory Agreement BX-6178MIT Lincoln Laboratory Agreement BX-6433National Aeronautics and Space Administration/Goddard Space Flight Center Grant NAS5-31376National Aeronautics and Space Administration/Goddard Space Flight Center Grant NAG5-10MIT Leaders for Manufacturing Progra

Radio Astronomy

Contains reports on eight research projects.National Science Foundation (Grant AST77-06052)Joint Services Electronics Program (Contract DAAG29-78-C-0020)National Aeronautics and Space Administration (Contract NAS5-21980)U. S. Department of Commerce - National Oceanic and Atmospheric Administration (Grant 04-8-M01-1)National Aeronautics and Space Administration (Contract NAS5-22929)National Aeronautics and Space Administration (Contract NAS5-23677)National Science Foundation (Grant AST77-12960)National Science Foundation (Grant AST77-26896