Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey (USGS) Publication_Date: 10-DEC-08 Title: SRTM Water Body Data: SWBDW111N43N Online_Linkage: http://earthexplorer.usgs.gov Description: Abstract: The SRTM Water Body Data files are a by-product of the data editing performed by the National Geospatial-Intelligence Agency (NGA) to produce the finished SRTM Digital Terrain Elevation Data Level 2 (DTED® 2). In accordance with the DTED® 2 specification, the terrain elevation data have been edited to portray water bodies that meet minimum capture criteria. Ocean, lake and river shorelines were identified and delineated. Lake elevations were set to a constant value. Ocean elevations were set to zero. Rivers were stepped down monotonically to maintain proper flow. After this processing was done, the shorelines from the one arc second (approx. 30-meter) DTED® 2 were saved as vectors in ESRI 3-D Shapefile format. Supplemental_Information: In most cases, two orthorectified image mosaics (one for ascending passes and one for descending passes) at a one arc second resolution were available for identifying water bodies and delineating shorelines in each 1 x1 cell. These were used as the primary source for water body editing. The guiding principle for this editing was that water must be depicted as it was in February 2000 at the time of the shuttle flight. A Landcover water layer and medium-scale maps and charts were used as supplemental data sources, generally as supporting evidence for water identified in the image mosaics. Since the Landcover water layer was derived mostly from Landsat 5 data collected a decade earlier than the Shuttle mission and the map sources had similar currency problems, there were significant seasonal and temporal differences between the depiction of water in the ancillary sources and the actual extent of water bodies in February 2000 in many instances. In rare cases, where the SRTM image mosaics were missing or unusable, Landcover was used to delineate the water in the SRTM cells. The DTED® header records for those cells are documented accordingly. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 01-FEB-02 Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -111 East_Bounding_Coordinate: -110 North_Bounding_Coordinate: 44 South_Bounding_Coordinate: 43 Data_Set_G-Polygon: Data_Set_G-Polygon_Outer_G-Ring: G-Ring_Latitude: 44 G-Ring_Longitude: -111 G-Ring_Latitude: 44 G-Ring_Longitude: -110 G-Ring_Latitude: 43 G-Ring_Longitude: -110 G-Ring_Latitude: 43 G-Ring_Longitude: -111 Keywords: Theme: Theme_Keyword: National Imagery and Mapping Agency Theme_Keyword: Radar Theme_Keyword: JPL Theme_Keyword: NGA Theme_Keyword: Water Body Theme_Keyword: Elevation Theme_Keyword: SRTM Theme_Keyword: Mapping Use_Constraints: There is no guarantee of warranty concerning the accuracy of these data. Users should be aware that temporal changes may have occurred since the data was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of their limitations. Acknowledgement of the originating agencies would be appreciated in products derived from these data. Any user who modifies the data set is obligated to describe the types of modifications they perform. User specifically agrees not to misrepresent the data set, nor to imply that changes made were approved or endorsed by the U.S. Geological Survey. Please refer to http://www.usgs.gov/privacy.html for the USGS disclaimer. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: lta@usgs.gov Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Earth Resources Observation and Science (EROS) Center Contact_Person: lta@usgs.gov Contact_Position: Long Term Archive (LTA) Representative Contact_Address: Address_Type: mailing and physical address Address: Long Term Archive (LTA), U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center 47914 252nd Street City: Sioux Falls State_or_Province: SD Postal_Code: 57198-0001 Country: USA Contact_Electronic_Mail_Address: lta@usgs.gov Hours_of_Service: 0800 - 1600 CT, M-F, -6 h GMT Contact_Instructions: Security_Information: Security_Classification_System: none Security_Classification: unclassified Security_Handling_Description: none Native_Data_Set_Environment: Oracle Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The identification of features is provided by the distinct electromagnetic energy it emits,reflects, or otherwise transmits. This is called the spectral signature. Other signatures such as tone (lightness or darkness), texture (surface roughness or smoothness), pattern,shadow, shape, and size are as important. Thus, through the use of the thematic mapper sensor, such elements as water features, soils, and vegetation can be identified and distinguished from each other. Lineage: Process_Step: Process_Description: SRTM data were processed from raw radar echoes into digital elevation models at the Jet Propulsion Laboratory (JPL) in Pasadena, CA. These original data files had samples spaced ("posted") at intervals of 1 arc-second of latitude and longitude (about 30 meters at the equator). These data were then edited by the National Geospatial Intelligence Agency (NGA, formerly the National Imagery and Mapping Agency), and distributed as part of their DTED® product set. The editing, also referred to as finishing, consisted of delineating and flattening water bodies, better defining coastlines, removing "spikes" and "wells", and filling small voids. This "finished" set is publicly available at two postings: 1 arc-second for the United States and its territories and possessions, and 3 arc-seconds for regions between 60 degrees North and 56 degrees South latitude. Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: lta@usgs.gov Contact_Organization_Primary: Contact_Organization: NGA Contact_Person: lta@usgs.gov Contact_Position: Long Term Archive (LTA) Representative Contact_Address: Address: Long Term Archive (LTA), U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center 47914 252nd Street Contact_Electronic_Mail_Address: lta@usgs.gov Contact_Instructions: lta@usgs.gov Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: lta@usgs.gov Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Earth Resources Observation and Science (EROS) Center Contact_Person: lta@usgs.gov Contact_Position: Long Term Archive (LTA) Representative Contact_Address: Address_Type: mailing and physical address Address: Long Term Archive (LTA), U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center 47914 252nd Street City: Sioux Falls State_or_Province: SD Postal_Code: 57198-0001 Country: USA Contact_Electronic_Mail_Address: lta@usgs.gov Hours_of_Service: 0800 - 1600 CT, M-F, -6 h GMT Contact_Instructions: lta@usgs.gov Distribution_Liability: Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the USGS regarding the use of the data on any other system, nor does the act of distribution constitute any such warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Option: Offline_Option: Recording_Format: Varies Fees: Typically, all data available from USGS/EROS are downloadable at no cost to the user. there are some cases when a service fee is required to convert the analog film record to a digital file. This non-refundable fee is $30 per scene/frame. Ordering_Instructions: Consult the data sets product page for specific information. Turnaround: A majority of the data are available for immediate downloading. Specific data processing may take 24 to 48 hours and film scanning service requests involving payment to USGS can require 3 - 4 weeks upon successful payment of the request. Custom_Order_Process: Limited from data set to data set. Please consult the data sets product page for specific information. Technical_Prerequisites: Adequate computer capability is the only technical prerequisite for viewing data in digital form. You may return here at any time and add to your data request before final submission. Metadata_Reference_Information: Metadata_Review_Date: as needed Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: lta@usgs.gov Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Earth Resources Observation and Science (EROS) Center Contact_Person: lta@usgs.gov Contact_Position: Long Term Archive (LTA) Representative Contact_Address: Address_Type: mailing and physical address Address: Long Term Archive (LTA), U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center 47914 252nd Street City: Sioux Falls State_or_Province: South Dakota Postal_Code: 57198-0001 Country: USA Contact_Electronic_Mail_Address: lta@usgs.gov Hours_of_Service: 0800 - 1600 CT, M-F, -6 h GMT Contact_Instructions: lta@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998, Version 2 Metadata_Time_Convention: local time Metadata_Access_Constraints: None Metadata_Use_Constraints: None Metadata_Security_Information: Metadata_Security_Classification_System: None Metadata_Security_Classification: Unclassified Metadata_Security_Handling_Description: None