Shuttle Radar Topography Mission (SRTM) Elevation Data Set

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: National Aeronautics and Space Administration (NASA)

Originator: National Geospatial-Intelligence Agency (NGA)

Originator: German Aerospace Center (DLR)

Originator: Italian Space Agency (ASI)

Publication_Date: 2002

Title: Shuttle Radar Topography Mission (SRTM) Elevation Data Set

Geospatial_Data_Presentation_Form: SDE raster digital data

Publication_Information:

Publication_Place: Sioux Falls, SD

Publisher: U.S. Geological Survey

Online_Linkage: <http://seamless.usgs.gov>

Description:

Abstract:

The Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was assigned to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA, for NASA's Earth Science Enterprise, Washington, D.C.

Purpose:

The objective of the SRTM mission is to obtain elevation radar data on a near-global scale and generate the most complete high-resolution digital topographic database of the Earth. The information collected by SRTM will be used to provide a tool to enhance the activities of scientists, the military, commercial, and civilian users.

Supplemental_Information:

Additional Reference: <http://www.jpl.nasa.gov/srtm/index.html>

Processing Information:Program Name: SRTM2DSM_DTED_3.AMLObjective: Process srtm data to a digital surface model in grid format.Procedure:Copy filesRename to latlon.dt1 formatCreate GRIDDefine projection as geographic with WGS84 datumProject grid from decimal seconds to decimal degreesConvert to real data type

Environment:

COVERAGE	XMIN	YMIN	XMAX	YMAX	ZMIN	ZMAX	ZMEAN	ZSIGMA	ZUNITS	RESOLUTION	HDATUM	VDATUM	TIMESTAMP
N35W112	-112.000138889	34.999861111	-110.999861111	36.000138889	1175	3835	1835.156494141	337.260101318	METERS	0.000277778	WGS84	WGS84_GEOID	10 Mar 04 15:03:53 Wednesday

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20000211

Ending_Date: 20000222

Currentness_Reference: publication date

Status:

Progress: In work

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate:-111.07713599

East_Bounding_Coordinate:-111.00129364

North_Bounding_Coordinate:35.04263325

South_Bounding_Coordinate:35.00780195

Data_Quality_Information:

Logical_Consistency_Report:

To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices

Completeness_Report: Shuttle Radar Topography Mission (SRTM) Elevation Data Set

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:

Source_Information:

Source_Citation:

Citation_Information:

Originator: NASA, NGA, DLR, and ASI

Publication_Date: 2002

Title: SRTM Data Collection

Type_of_Source_Media: raster digital data

Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20020211

Ending_Date: 20020222

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: SRTM 2000

Source_Contribution: NASA, NGA, DLR, and ASI

Source_Information:

Source_Citation:

Citation_Information:

Originator: Jet Propulsion Laboratory

Publication_Date: 2002

Title: JPL Processing

Online_Linkage: <ftp://edcsgs9.cr.usgs.gov/pub/srtm>

Type_of_Source_Media: raster digital data

Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20020211

Ending_Date: 20020222

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: JPL 2002

Source_Contribution: NASA, NGA, DLR, and ASI

Source_Information:

Source_Citation:

Citation_Information:

Originator: National Geospatial-Intelligence Agency

Publication_Date: 2002

Title: NGA Processing

Type_of_Source_Media: raster digital data

Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20020211

Ending_Date: 20020222

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: NGA 2003

Source_Contribution: NASA, NGA, DLR, and ASI

Source_Information:

Source_Citation:

Citation_Information:

Originator:

U.S. Geological Survey, The National Center for Earth Resources Observation and Science (EROS)

Publication_Date: 2004

Title: EROS Processing

Online_Linkage: <http://seamless.usgs.gov>

Type_of_Source_Media: raster digital data

Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20020211

Ending_Date: 20020222

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: EROS 2003

Source_Contribution: NASA, NGA, DLR, and ASI

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 NGA, 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. NGA 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

Process_Date: 2002

Source_Produced_Citation_Abbreviation: JPL 2002

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

National Aeronautics and Space Administration (NASA) Jet Propulsion Lab (JPL)

Contact_Position: N/A

Contact_Address:

Address_Type: mailing address

Address: 4800 Oak Grove Drive

City: Pasadena

State_or_Province: CA

Postal_Code: 91009

Country: USA

Contact_Voice_Telephone: (818) 354-4321

Contact_TDD/TTY_Telephone: N/A

Contact_Facsimile_Telephone: N/A

Contact_Electronic_Mail_Address: N/A

Process_Step:

Process_Description:

After NASA/JPL completes the raw data processing, NGA performs quality assurance checks on the JPL SRTM data and then carries out several additional finishing steps. Spikes and wells in the data are detected and voided out if they exceed 100 meters compared to surrounding elevations. Small voids (16 contiguous posts or less) are filled by interpolation of surrounding elevations. Large voids are left in the data. Water bodies are depicted in the SRTM DTED®. The ocean elevation is set to 0 meters. Lakes of 600 meters or more in length are flattened and set to a constant height. Rivers that exceed 183 meters in width are delineated and monotonically stepped down in height. Islands are depicted if they have a major axis exceeding 300 m or the relief is greater than 15 m. The data are processed in one degree by one degree "cells". The edges of each cell are matched with the edges of adjacent cells to assure continuity.

Source_Used_Citation_Abbreviation: JPL 2002

Process_Date: 2002

Source_Produced_Citation_Abbreviation: NGA 2003

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

National Aeronautics and Space Administration (NASA) Jet Propulsion Lab (JPL)

Contact_Position: N/A

Contact_Address:

Address_Type: mailing address

Address: 4800 Oak Grove Drive

City: Pasadena

State_or_Province: CA

Postal_Code: 91009

Country: USA

Contact_Voice_Telephone: (818) 354-4321

Contact_Facsimile_Telephone: n/a

Contact_Electronic_Mail_Address: n/a

Contact_Instructions: <http://www.jpl.nasa.gov/about_JPL/>

Process_Step:

Process_Description:

Process SRTM data to a digital surface model in grid format. To complete this step run SRTM2DSM_3_DTED.AML which renames the data files, creates a GRID, defines projection as geographic with WGS84 datum, project grid from decimal seconds to decimal degrees, and converts to real data type.

Source_Used_Citation_Abbreviation: NGA 2003

Process_Date: 2002

Source_Produced_Citation_Abbreviation: EROS 2003

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: National Geospatial-Intelligence Agency

Contact_Position: n/a

Contact_Address:

Address_Type: mailing address

Address: n/a

City: Bethesda

State_or_Province: MD

Postal_Code: 20816-5003

Contact_Voice_Telephone: (818) 354-4321

Contact_Facsimile_Telephone: n/a

Contact_Electronic_Mail_Address: n/a

Contact_Instructions: <http://www.nga.mil>

Process_Step:

Process_Description:

The metadata was imported and updated for display through the Seamless Data Distribution System.

Process_Date: 2004

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: National Center for Earth Resorces Observation and Science

Contact_Position: Customer Service Representative

Contact_Address:

Address_Type: mailing and physical address

Address: National Center for Earth Resorces Observation and Science

City: Sioux Falls

State_or_Province: SD

Postal_Code: 57198

Country: USA

Contact_Voice_Telephone: 605-594-6151

Contact_TDD/TTY_Telephone: 605-594-6933

Contact_Facsimile_Telephone: 605-594-6589

Contact_Electronic_Mail_Address: custserv@usgs.gov

Hours_of_Service: 8-4 CT, M-F

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Pixel

Row_Count: 270000

Column_Count: 1296000

Vertical_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 1.000000

Longitude_Resolution: 1.000000

Geographic_Coordinate_Units: Decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: D_WGS_1984

Ellipsoid_Name: WGS_1984

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257224

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: N/A

Altitude_Resolution: 1.000000

Altitude_Distance_Units: meters

Altitude_Encoding_Method:

Explicit elevation coordinate included with horizontal coordinates

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview: N/A

Entity_and_Attribute_Detail_Citation: N/A

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

The National Center for Earth Resources Observation and Science (EROS)

Contact_Position: Customer Services Representative

Contact_Address:

Address_Type: mailing and physical address

Address:

U.S. Geological Survey, The National Center for Earth Resources Observation and Science (EROS)

City: Sioux Falls

State_or_Province: SD

Postal_Code: 57198

Country: USA

Contact_Voice_Telephone: 605-594-6151

Contact_TDD/TTY_Telephone: 605-594-6933

Contact_Facsimile_Telephone: 605-594-6589

Contact_Electronic_Mail_Address: custserv@usgs.gov

Hours_of_Service: 8-4 CT, M-F

Resource_Description: Downloadable Data

Distribution_Liability:

Although these data have been processed successfully on a computer system at the U.S. Geological Survey, The National Center for Earth Resources Observation and Science (EROS), no warranty expressed or implied is made by either regarding the utility of the data on any system, nor shall the act of distribution constitute any such warranty. The USGS will warrant the delivery of this product in computer-readable format and will offer appropriate adjustment of credit when the product is determined unreadable by correctly adjusted computer peripherals, or when the physical medium is delivered in damaged condition. Requests for adjustments of credit must be made within 90 days from the date of this shipment from the ordering site.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: ARCE

Transfer_Size: 1.000

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name: <http://seamless.usgs.gov>

Fees: None

Metadata_Reference_Information:

Metadata_Date: 20050330

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

The National Center for Earth Resources Observation and Science (EROS)

Contact_Position: Customer Services Representative

Contact_Address:

Address_Type: mailing and physical address

Address:

U.S. Geological Survey, The National Center for Earth Resources Observation and Science (EROS)

City: Sioux Falls

State_or_Province: SD

Postal_Code: 57198

Country: USA

Contact_Voice_Telephone: 605-594-6151

Contact_TDD/TTY_Telephone: 605-594-6933

Contact_Facsimile_Telephone: 605-594-6589

Contact_Electronic_Mail_Address: custserv@usgs.gov

Hours_of_Service: 8-4 CT, M-F

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Access_Constraints: None

Metadata_Use_Constraints: None

Metadata_Security_Information:

Metadata_Security_Classification_System: N/A

Metadata_Security_Classification: Unclassified

Metadata_Security_Handling_Description: N/A

Metadata_Extensions:

Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>

Profile_Name: ESRI Metadata Profile