Elevation for the Eastern Caribbean (meters, 90 m grid)

Source: Lauretta Burke and Jon Maidens and contributing authors: Mark Spalding, Philip Kramer, Edmund Green, Suzie Greenhalgh, Hillary Nobles, Johnathan Kool. 2004. Reefs at Risk in the Caribbean.

Shuttle Radar Topography Mission (SRTM)

Shuttle Radar Topography Mission (SRTM) Elevation for the Eastern Caribbean (meters, 90 m grid)

Metadata also available as

Identification_Information:

Data_Quality_Information:

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:: The mission objective is to produce digital topographic map products with <=20 m absolute horizontal circular accuracy. All accuracies are quoted at the 90% level, consistent with National Map Accuracy Standards.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:: The mission objective is to produce digital topographic map products with <=16 m absolute vertical height accuracy and <= 10 m relative vertical height accuracy. All accuracies are quoted at the 90% level, consistent with National Map Accuracy Standards.

Lineage:

Process_Step:

Process_Description:

SRTM data is being processed in a systematic fashion using the SRTM Ground Data Processing System (GDPS) supercomputer system at the Jet Propulsion Laboratory. Data are being mosaicked into approximately 14,000 one degree by one degree cells and formatted according to the Digital Terrain Elevation Data (DTED) specification for delivery to NIMA, who will use it to update and extend their DTED products. Data are being processed on a continent-by-continent basis beginning with North America. NIMA will apply several post-processing steps to these data including editing, spike and well removal, water body leveling and coastline definition. Following these "finishing" steps data will be returned to NASA for distribution to the scientific and civil user communities, as well as the public.

However, in advance of that, some portion of the data processed by the GDPS is being released to Principal Investigators selected by NASA under the Solid Earth and Natural Hazards program, in response to requests for specific research programs.

Each SRTM data tile contains a mosaic of elevations generated by averaging all data takes that fall within that tile. Since the primary error source in synthetic aperture radar data is speckle, which has the characteristics of random noise, combining data through averaging reduces the error by the square root of the number of data takes used. In the case of SRTM the number of data takes could range from a minimum of one (in a very few cases) up to as many as ten.

As with all digital geospatial data sets, users of SRTM must be aware of certain characteristics of the data set (resolution, accuracy, method of production and any resulting artifacts, etc.) in order to better judge its suitability for a specific application. A characteristic of SRTM that renders it unsuitable for one application may have no relevance as a limiting factor for its use in a different application.

No editing has been performed on the data, and the elevation data in particular contain numerous voids and other spurious points such as anomalously high (spike) or low (well) values. Water bodies will generally not be well-defined - in fact since water surfaces generally produce very low radar backscatter they will appear quite "noisy" or rough, in the elevations data. Similarly, coastlines will not be well-defined.

Source_Used_Citation_Abbreviation: SRTM 2000

Source_Produced_Citation_Abbreviation: JPL 2002

Process_Step:

Process_Description:: Scenes downloaded and mosaiced to gether at the World Resources Institute (WRI) for the purposes of the Reefs at Risk Caribbean Project (<http://reefsatrisk.wri.org>). then projected into Lambert Equal Area Azimuthal (-76, 16)

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Grid Cell
Row_Count: 13633
Column_Count: 19803
Vertical_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Lambert Azimuthal Equal Area

Lambert_Azimuthal_Equal_Area:

Longitude_of_Projection_Center: -76.000000
Latitude_of_Projection_Center: 16.000000
False_Easting: 0.000000
False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: row and column

Coordinate_Representation:

Abscissa_Resolution: 90.000000
Ordinate_Resolution: 90.000000

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: D_Sphere_ARC_INFO
Ellipsoid_Name: Sphere_ARC_INFO
Semi-major_Axis: 6370997.000000
Denominator_of_Flattening_Ratio: infinity

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: dem_srtm

Attribute:

Attribute_Label: ObjectID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:: Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Value
Attribute_Definition: average elevation in meters

Attribute:

Attribute_Label: Count

Distribution_Information:

Resource_Description: Downloadable Data

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Transfer_Size: 8.448

Continued.

WRI Content Archive

Topic Areas

Elevation for the Eastern Caribbean (meters, 90 m grid)

Shuttle Radar Topography Mission (SRTM) Elevation for the Eastern Caribbean (meters, 90 m grid)

Metadata: