MODIS/Terra Near Real Time (NRT) Sea Ice Extent 5-Min L2 Swath 1km (C005)Entry ID: MOD29_C5_NRT
Abstract: MODIS/Terra Near Real Time (NRT) Sea Ice Extent 5-Min L2 Swath 1km (MOD29) contains the following fields: sea ice by reflectance, sea ice by reflectance pixel quality assurance (QA), ice surface temperature (IST), IST pixel QA, sea ice by IST, combined sea ice, latitudes, and longitudes in HDF-EOS format, along with corresponding metadata. Latitude and longitude geolocation fields are at 5 km ... resolution, while all other fields are at 1 km resolution. Version 4 (V004) is the latest version of MOD29 data available. MODIS/Terra V004 data extend from 24 February 2000 to present. The sea ice algorithm uses a Normalized Difference Snow Index (NDSI) modified for sea ice to distinguish sea ice from open ocean, based on reflective and thermal characteristics. The only data available for Version 4 (V004) is the Golden Month, which is a sample of V004 data covering the time period 29 August 2002 (day of year 241) through 7 October 2002 (day of year 280). The Golden Month is only available by special request by contacting NSIDC User Services. Please note that NSIDC now has a complete series of Version 5 data, which is the highest version number now available and represents the best quality of data.
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Data Set Citation
Start Date: 2015-12-27Stop Date: 2016-01-07
Temporal Resolution: 5 minutes
ISO Topic Category
Quality All MODIS/Terra sea ice products are considered validated - stage 1 meaning that accuracy has been estimated using a small number of independent measurements obtained from selected locations and time periods and ground-truth/field program effort. Analysis of the quality of the sea ice data products is an ongoing activity. Specific information on the science quality of the sea ice data products is ... reported in the ScienceQualityFlagExplanation object in the CoreMetadata.0 global attribute. The URL for the quality assessment site is given in the product metadata and is linked to from the EOS Data Gateway (EDG) when ordering data. The ScienceQualityFlagExplanation is changed in response to analysis and should be checked for updated information. In the MOD29 and MOD29P1D data products there are two instances of the ScienceQualityFlagExplanation, one for sea ice determined by reflectance data and one for IST written in the metadata. Information on both is posted at that URL. The Ice Surface Temperature PixelQA and the Sea Ice by Reflectance PixelQA data fields provide additional information on algorithm results for each pixel within a spatial context, and are used as a measure of usefulness for sea ice data. QA data are stored as bit flags. QA information is extracted by reading the bits within a byte (See MODIS Sea Ice Quality Assurance Fields). The QA information tells if algorithm results were nominal, abnormal, or if other defined conditions were encountered for a pixel (Riggs, Hall, and Salomonson 2003). See MODIS Land Quality Assessment for further details.
Data Set Progress
Extended Metadata Properties
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