GHRC News

LANCE logoThe near real-time LANCE AMSR-E system at the AMSR-E SIPS and GHRC DAAC is pleased to announce that we have integrated a new Version 11 L2A near real-time algorithm from Remote Sensing Systems (RSS) into our processing systems. These much improved version 11 brightness temperatures, as well as the corresponding L2B and L3 daily derived products, are available in the operational areas on our lance servers.

This new near real-time (NRT) L2A algorithm is comparable to the Version 11 L2A algorithm currently used at the AMSR-E SIPS. We are seeing only very small differences (less than 1 Kelvin in most cases) in the data produced by the new NRT Version 11 algorithm compared to the Version 11 standard data product algorithm.
The primary differences between the new Version 11 NRT L2A code and the L2A science code used in the SIPS for generating research-quality L2A brightness temperatures are:

  • For estimating the cold mirror spillover at 7-GHz, a climatology for the Earth's 7-GHz antenna temperature (TA) is used. The SIPS science code uses a combination of climatology and actual observations, when available. However using actual observations requires saving data from the previous orbit. The error introduced by this simplification for NRT processing is the spillover value (0.004) times the error in specifying TA (typically 15 K). Thus the typical error in the L2A brightness temperature at 7-GHz is 0.06 K.
  • For NRT processing, the effective temperature for the hot load is computed from a static table as compared to the SIPS science code that uses a dynamic effective temperature based on ancillary data. The science code also averages over the previous orbit to obtain a smoothed effective temperature. The typical error between the static and dynamic effective temperature is 0.2 K but can be higher at certain times of the year and latitudes.

The Version 11 NRT data are significantly improved compared to the current Version 9 NRT data. A major improvement from the current NRT algorithm is:

  • RSS added the glint angles of the DirecTV 1 0 and 11 satellites to the Geostationary_Satellite_Glint_Angles field. The low glint angles correlate well with the recent observed RFI artifacts. Over oceans, RFI can be intense: +50 K for 18.7V, and +100 K for 18.7H. Cases this large correspond to low wind conditions with very smooth seas. Initial analysis over land did not reveal significant RFI impacts. The affected period for this RFI is from July, 2007 forward.

We will continue to evaluate the version 11 NRT data during the next year and document our findings on our LANCE site at http://lance.nsstc.nasa.gov/.

 

LPVEx logoThe Light Precipitation Evaluation Experiment (LPVEx) took place in the Gulf of Finland during September and October, 2010. Microphysical properties, associated remote sensing observations, and coordinated model simulations of high latitude precipitation systems to drive the evaluation and development of precipitation algorithms for current and future satellite platforms were collected. LPVEx consisted of coordinated aircraft flights within an extensive network of ground-based observations that included three dual-polarization, C-band, Doppler radars, a network of surface weather and sounding stations, several micro-rain radars, and surface rainfall and drop size distribution (DSD) measurements from a large number of rain gauges and disdrometers. LPVEx was a collaborative effort between CloudSat, the GPM Ground Validation (GV) program, the Finnish Meteorological Institute (FMI), Environment Canada (EC), the United Kingdom National Environmental Research Council, Vaisala Inc., and the University of Helsinki (UH).

The GHRC is the archive and distribution center for data collected during the LPVEx experiment.

 

The AMSR-E SIPS at the GHRC DAAC would like to announce the availability of AMSR-E near real-time data subscriptions.
With a data subscription, we will push selected data products to a designated computer as soon as the products are generated. In order to receive these products via subscription, you must be a registered LANCE user. Please let us know if you are interested in using our subscription service for AMSR-E near real-time data.

More information about LANCE AMSR-E near real-time data is available at
http://lance.nsstc.nasa.gov/.

 

LANCE logoThe AMSR-E SIPS at the GHRC DAAC has implemented incremental daily processing for our AMSR-E near real-time Level 3 daily (Ocean, Land, Snow, Sea Ice ) products. Partial products are created several times per day (currently every 3 hours) using whatever L2 data is available at the time of creation, in order to reduce latency for these products.

These partial products (identified by "P") will be available in the same FTP directories as the complete real-time daily products (identified by "R"). Each new partial product for a given day will have the same file name as the previously-generated one, but will incorporate additional input files. A new partial product can be distinguished by creation time shown in the directory listing. Once the full daily file is available the partial file for that day will be deleted.

More information about LANCE AMSR-E near real-time data is available at http://lance.nsstc.nasa.gov/.

 

 

LANCE logoThe AMSR-E SIPS at the GHRC DAAC would like to announce the expanded availability of AMSR-E near real-time data products through the Land Atmosphere Near-real-time Capability for EOS (LANCE). These near real-time swath and daily products are generally available to registered users within three hours of observation. In order to provide for full system redundancy, the SIPS has implemented a second string ftp server at ftp://lance2.itsc.uah.edu. Users should obtain data from this location in the event that the primary LANCE ftp server (ftp://lance.nsstc.nasa.gov) is unavailable. Both strings are located on the UAHuntsville campus and managed by SIPS personnel, but are located in different buildings and connected to different networks. Redundant processing strings will greatly reduce the possibility of data being unavailable due to system outages.

More information about LANCE AMSR-E near real-time data is available at
http://lance.nsstc.nasa.gov/.

 

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