National POES System (NPOESS) is scheduled to fly during the 2007-2010 period. The impact of future instruments such as Doppler Wind Lidar need to be assessed with experiments using simulated observations. These experiments are known as Observing System Simulation Experiments (OSSEs). OSSE will provide a guideline for selection and design of the instrument.

This project is a collaboration among several organizations. Data assimilation will be performed mainly by a technology-neutral organization, the National Centers for Environmental Prediction (NCEP) and repeated by NASA/Data Assimilation Office (DAO). Simpson Weather Associates (SWA) and NOAA scientists are participating in the simulation of Doppler Wind Lidar (DWL) observations, and the National Environmental Satellite, Data and Information Service (NESDIS) will simulate both existing and future thermodynamic sounders. NASA/DAO will simulate conventional observations including ACARS and cloud track winds.

Prior to testing DWL, data impact of existing instruments in real and simulated data are compared for calibration. The impact test showed satisfactory similarity between real and simulated analysis for impact assessment for a DWL.

For DWL OSSE, the bracketing OSSEs are being performed for various concepts to bound the technology neutral potential impact. Scanning: wavelength; data sampling strategies: various error characterizations are tested through the bracketing OSSE. Systematic errors, various representativeness errors, and large scale correlated errors are also tested. The initial results show the impact is sensitive to error assignment. Scanning is most important in upper atmosphere.

Through OSSE at operational centeres, the operational data assimilation systems will be ready to handle new data in time for the launch. This process involves the evaluation of the operational load, the development of the data base and data-processing, and a quality control system. All of this development will accelerate the operational use of data from the future instruments.

OSSE for other instruments such as atmospheric infrared sounder (AIRS), cross track infrared sounder (CrIS), conically scanning microwave imager/sounder (CMIS), advanced technology microwave sounder (ATMS) are also under preparation.