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GPM Ground Validation Environment Canada (EC) Vaisala Ceilometer GCPEx Table of Contents
The GPM Ground Validation Environment Canada (EC) Vaisala Ceilometer GCPEx data set was collected by Environment Canada (EC) during the GPM Cold-season Precipitation Experiment (GCPEx) in Huronia, Canada from January 15, 2012 through March 1, 2012. The CT25K ceilometer uses pulsed diode laser LIDAR technology to derive backscatter profiles, cloud heights and vertical visibilities. It is also able to detect 3 cloud layers simultaneously. The ceilometer data is available in ASCII text format. The browse files feature daily quick look plots that display clouds heights over time. CampaignThe GPM Cold-season Precipitation Experiment (GCPEx) occurred in Ontario, Canada during the winter season of 2011-2012. GCPEx addressed shortcomings in the GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. These data sets were collected to aid in the achievement of the over arching goal of GCPEx which is to characterize the ability of multi-frequency active and passive microwave sensors to detect and estimate falling snow. During GCPEx, a Vaisala Ceilometer was located at the Huronia site in Ontario, Canada. The location of the Huronia site is:
Data was collected from January 15, 2012 to March 1, 2012. Further details on GCPEx are available at http://gpm.nsstc.nasa.gov/gcpex. Information on the Global Precipitation Measurement (GPM) mission is available at http://pmm.nasa.gov/GPM. Instrument DescriptionThe Vaisala CT25K Ceilometer measures the time needed for a short pulse of light to travel from the transmitter of the ceilometer to a backscattering cloud base and back to the transmitter. The instantaneous magnitude of the returned signal provides information on the backscatter properties of the atmosphere at a certain height. The return signal can also be used to derive information about fog, precipitation, and clouds. Fog and precipitation attenuate the signal. Therefore cloud bases will appear lower in magnitude in the return echo. In a normal range of operation, the Vaisala CT25K samples the return signal every 100 nanoseconds starting within 0 to 50 microseconds of operation. This provides a spatial resolution of 50 feet from the ground to 25,000 feet from the ground. More information on the operating principles and design specifications of the CT25K can be found in the CT25K User's Guide. InvestigatorsDavid Hudak The GPM Ground Validation Environment Canada (EC) Vaisala Ceilometer GCPEx data and browse files are named with the following convention:
where, Data Format The GPM Ground Validation Environment Canada (EC) Vaisala Ceilometer GCPEx data set is available in ASCII text format. The files contain minutely time stamped 'Message 2' outputs. For more information on the format of the data and on the 'Message 2' outputs, please see the Data Messages section of the CT25K User's Guide. The GPM Ground Validation Environment Canada (EC) Vaisala Ceilometer GCPEx browse files are available as .png (portable network graphics) image files. The browse files feature daily plots of cloud ceiling heights over time. CitationOur data sets are provided through the NASA Earth Science Data and Information System (ESDIS) Project and the Global Hydrology Resource Center (GHRC) Distributed Active Archive Center (DAAC). GHRC DAAC is one of NASA's Earth Observing System Data and Information System (EOSDIS) data centers that are part of the ESDIS project. ESDIS data are not copyrighted; however, in the event that you publish our data or results derived by using our data, we request that you include an acknowledgment within the text of the article and a citation on your reference list. Examples for general acknowledgments, data set citation in a reference listing, and crediting online web images and information can be found at: http://ghrc.nsstc.nasa.gov/uso/citation.html Contact InformationTo order these data or for further information, please contact:
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