SRTM Global Digital Elevation Model

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: U.S. Geological Survey Center for Earth Resource Observation and Science (EROS)
Originator: National Aeronautics and Space Administration (NASA)
Originator: National Geospatial-Intelligence Agency (NGA)
Originator: ESRI
Publication_Date: 20061001
Title:
SRTM Global Digital Elevation Model
Edition: 2006
Geospatial_Data_Presentation_Form: SDE raster digital data
Series_Information:
Series_Name: ESRIr Data & Maps
Issue_Identification: 2006 World, Europe, United States, Canada, and Mexico
Publication_Information:
Publication_Place: Redlands, California, USA
Publisher: ESRI
Other_Citation_Details:
Location: Elevation and Image Data - World DVD \srtm_void_filled\elevation
Description:
Abstract:
SRTM Global Digital Elevation Model (North Central, one of six data sets) represents an elevation map (between 60 degrees North and 56 degrees South latitude) of the world from the NASA/NGA Shuttle Radar Topography Mission (SRTM) data sets from the U.S. Geological Survey's EROS Data Center. The resolution is 3 arc seconds (90 meters). The pixel value represents the elevation in meters.
Purpose:
SRTM Global Digital Elevation Model provides a base map layer displaying elevation information between 60 degrees North and 56 degrees South latitude for geographic analysis on regional and national scales.
Supplemental_Information:
Largest scale when displaying the data: 1:250,000.
Time_Period_of_Content:
Time_Period_Information:
Multiple_Dates/Times:
Single_Date/Time:
Calendar_Date: 200002
Single_Date/Time:
Calendar_Date: 20050401
Currentness_Reference:
ground condition: 200002; publication date: 20050401
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Annually
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -31.999583
East_Bounding_Coordinate: 67.999584
North_Bounding_Coordinate: 60.000416
South_Bounding_Coordinate: -2.000417
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: image
Theme_Keyword: SRTM
Theme_Keyword: elevation
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Global
Place_Keyword: World
Place_Keyword: North America
Place_Keyword: South America
Place_Keyword: Africa
Place_Keyword: Europe
Place_Keyword: Asia
Place_Keyword: Australia
Temporal:
Temporal_Keyword_Thesaurus: None
Temporal_Keyword: 2000
Temporal_Keyword: 2005
Access_Constraints: Access granted to Licensee only.
Use_Constraints:
The data are provided by multiple, third party data vendors under license to ESRI for inclusion on ESRI Data & Maps for use with ESRIr software.  Each data vendor has its own data licensing policies and may grant varying redistribution rights to end users. Please consult the redistribution rights below for this data set provided on ESRI Data & Maps. As used herein, "Geodata" shall mean any digital data set consisting of geographic data coordinates and associated attributes.

The redistribution rights for this data set: Redistribution rights are granted by the data vendor for hard-copy renditions or static, electronic map images (e.g. .gif, .jpeg, etc.) that are plotted, printed, or publicly displayed with proper metadata and source/copyright attribution to the respective data vendor(s).  Geodata is redistributable with a Value-Added Software Application developed by ESRI Business Partners on a royalty-free basis with proper metadata and source/copyright attribution to the respective data vendor(s).

The terms and conditions below apply to all the data sets provided on ESRI Data & Maps.

Proprietary Rights and Copyright: Licensee acknowledges that the Data and Related Materials contain proprietary and confidential property of ESRI and its licensor(s). The Data and Related Materials are owned by ESRI and its licensor(s) and are protected by United States copyright laws and applicable international copyright treaties and/or conventions.

Limited Warranty and Disclaimer: ESRI warrants that the media upon which the Data and Related Materials are provided will be free from defects in materials and workmanship under normal use and service for a period of ninety (90) days from the date of receipt.

THE DATA AND RELATED MATERIALS ARE EXCLUDED FROM THE LIMITED WARRANTY, AND THE LICENSEE EXPRESSLY ACKNOWLEDGES THAT THE DATA CONTAINS SOME NONCONFORMITIES, DEFECTS, OR ERRORS. ESRI DOES NOT WARRANT THAT THE DATA WILL MEET LICENSEE'S NEEDS OR EXPECTATIONS; THAT THE USE OF THE DATA WILL BE UNINTERRUPTED; OR THAT ALL NONCONFORMITIES, DEFECTS, OR ERRORS CAN OR WILL BE CORRECTED. ESRI IS NOT INVITING RELIANCE ON THIS DATA, AND THE LICENSEE SHOULD ALWAYS VERIFY ACTUAL DATA.

EXCEPT FOR THE LIMITED WARRANTY SET FORTH ABOVE, THE DATA AND RELATED MATERIALS CONTAINED THEREIN ARE PROVIDED "AS-IS," WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

HIGH RISK ACTIVITIES: 
(A) THE DATA AND RELATED MATERIALS ARE NOT FAULT-TOLERANT AND ARE NOT DESIGNED, MANUFACTURED, OR INTENDED FOR USE OR RESALE FOR INSURANCE UNDERWRITING OR WITH CRITICAL HEALTH AND SAFETY OR ONLINE CONTROL EQUIPMENT IN HAZARDOUS ENVIRONMENTS THAT REQUIRE FAIL-SAFE PERFORMANCE, INCLUDING, BUT NOT LIMITED TO THE OPERATION OF NUCLEAR FACILITIES, NAVIGATION OR GUIDANCE (I.E., AIRCRAFT, NAUTICAL VEHICLE, ETC.), OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL, EMERGENCY RESPONSE, TERRORISM PREVENTION OR RESPONSE, LIFE SUPPORT, OR WEAPONS SYSTEMS ("HIGH RISK ACTIVITIES"). ESRI SPECIFICALLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.

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Exclusive Remedy and Limitation of Liability: The entire liability of ESRI or its licensor(s) and Licensee's exclusive remedy shall be to terminate the Agreement upon Licensee returning the Data and Related Materials to ESRI with a copy of Licensee's invoice/receipt and ESRI returning the license fees paid to Licensee.

IN NO EVENT SHALL ESRI AND/OR ITS LICENSOR(S) BE LIABLE FOR COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOST PROFITS, LOST SALES, OR BUSINESS EXPENDITURES, INVESTMENTS, OR COMMITMENTS IN CONNECTION WITH ANY BUSINESS; LOSS OF ANY GOODWILL; OR FOR ANY INDIRECT, SPECIAL, INCIDENTAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT OR USE OF THE DATA AND RELATED MATERIALS, HOWEVER CAUSED, ON ANY THEORY OF LIABILITY, AND WHETHER OR NOT ESRI OR ITS LICENSOR(S) HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. THESE LIMITATIONS SHALL APPLY NOTWITHSTANDING ANY FAILURE OF ESSENTIAL PURPOSE OF ANY EXCLUSIVE REMEDY.

Third Party Beneficiary: ESRI's licensor(s) has (have) authorized ESRI to (sub)distribute and (sub)license its (their) data as incorporated into the Data and Related Materials. As an intended third party beneficiary to this Agreement, the ESRI licensor(s) is (are) entitled to directly enforce, in its own name, the rights and obligations undertaken by the Licensee and to seek all legal and equitable remedies as are afforded to ESRI.

In the event that the data vendor(s) has (have) granted the end user permission to redistribute the Geodata, please use proper proprietary or copyright attribution for the various data vendor(s), and provide the associated metadata file(s) with the Geodata. In compliance with FGDC metadata standards, ESRI has attempted to practice proper metadata methodologies by providing any data source information, descriptions, and file names to assist in this effort.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: ESRI
Contact_Person: Data Team
Contact_Address:
Address_Type: mailing and physical address
Address:
380 New York Street
City: Redlands
State_or_Province: California
Postal_Code: 92373-8100
Country: USA
Contact_Voice_Telephone: 909-793-2853
Contact_Facsimile_Telephone: 909-793-5953
Contact_Electronic_Mail_Address: info@esri.com
Hours_of_Service: 7:00 a.m.-5:30 p.m. Pacific time, Monday-Friday
Contact Instructions:
In the United States-
Please direct all inquiries regarding software/data pricing and consulting services to your local ESRI Regional Office.  For support, you may contact Technical Support by telephone (voice) between 6:00 a.m. and 5:00 p.m. Pacific time, Monday through Friday, by dialing 888-377-4575; facsimile (fax) available at 909-792-0960; electronic mail (e-mail) support@esri.com; or visit http://support.esri.com; ESRI holidays excluded. 

Outside the United States-
Please direct all inquiries regarding software/data pricing, sales, support, and consulting services to your local ESRI International Distributor.  This information can be found at http://gis.esri.com/intldist/contactint.cfm.  

For other questions or comments, you may contact ESRI headquarters by e-mail, telephone, or fax or write to us.
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.0.1279
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Data_Quality_Information:
Completeness_Report:
After processing, the data set is checked for drawing display and file sizes compared with source materials.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Conforms to the horizontal positional accuracy of the Shuttle Radar Topography Mission DTEDr Level 1 (3-arc second) Data.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
The SRTM vertical datum is mean sea level and is based on the WGS84 Earth Gravitational Model (EGM 96) geoid. The elevation values of the SRTM data (excluding void filled areas) are based on first reflective return, which means that the elevation value may represent bare earth, vegetation, or man-made features. The absolute height accuracy of the source SRTM data (excluding void filled areas) and prior to compression is "better than" 16 meters (at a 90% confidence level).

In order to distribute the elevation data on a single (dual layer) DVD9 it was necessary to compress the SRTM data using lossy JPEG2000 compression. The compression quality setting (5) introduced a vertical bias to the data. Based on a test of the Western United States against the original data values this equates to a RMS error of 2.15 (excluding void filled areas). The minimum difference was 0 meters and the maximum difference was +/- 30 meters.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey Center for Earth Resource Observation and Science (EROS)
Originator: National Aeronautics and Space Administration (NASA)
Originator: National Geospatial-Intelligence Agency (NGA)
Title:
Shuttle Radar Topography Mission DTEDr Level 1 (3-arc second) Data
Geospatial_Data_Presentation_Form: raster digital data
Publication_Information:
Publication_Place: Sioux Falls, South Dakota, USA
Publisher: U.S. Geological Survey Center for Earth Resource Observation and Science (EROS)
Other_Citation_Details:
SRTM is a cooperative project between NASA and NGA. Acknowledgement: Data available from USGS/EROS, Sioux Falls, South Dakota. Questions concerning the use or redistribution of USGS/EROS data should be directed to: USGS/EROS Customer Services Mundt Federal Building, Sioux Falls, SD 57198; Toll Free: 800-252-4547; Telephone: 605-594-6151; Facsimile: 605-594-6589; Email: custserv@usgs.gov
Online_Linkage: http://edcsns17.cr.usgs.gov/srtmdted/
Type_of_Source_Media: DVD-ROM
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 200002
Source_Currentness_Reference:
ground condition
Source_Citation_Abbreviation:
USGS/EROS SRTM DTED
Source_Contribution:
Attribute and geospatial data
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey, EROS Data Center Distributed Active Archive Center (EDC DAAC)
Originator: ESRI
Publication_Date: 20050401
Title:
Global Digital Elevation Model (GTOPO30)
Edition: 2005
Geospatial_Data_Presentation_Form: raster digital data
Series_Information:
Series_Name: ESRIr Data & Maps
Issue_Identification: 2005
Publication_Information:
Publication_Place: Redlands, California, USA
Publisher: ESRI
Online_Linkage: http://edc.usgs.gov/products/elevation/gtopo30/gtopo30.html
Online_Linkage: http://www.esri.com
Type_of_Source_Media: DVD-ROM
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 20050401
Source_Currentness_Reference:
publication date
Source_Citation_Abbreviation:
ESRI Data & Maps 2005
Source_Contribution:
Attribute and geospatial data
Process_Step:
Process_Description:
SRTM DTED is a uniform matrix of elevation values indexed to specific points on the ground. The horizontal datum is the World Geodetic System 1984 (WGS84) and the vertical datum is mean sea level as determined by the WGS84 Earth Gravitational Model (EGM 96) geoid. The elevation data are with respect to the reflective surface, which may be vegetation, man-made features or bare earth. DTED Level 2 elevation values are spaced one arc second apart between 0 degrees and 50 degrees latitude, and spaced one arc second apart in latitude and two arc seconds apart in longitude between 50 degrees and 60 degrees latitude. SRTM DTED Level 1 values are derived from the SRTM DTEDr 2 values such that the DTED 1 values are identical to the DTED 2 values at coincident points. However, the SRTM DTED 1 values are spaced 3 arc seconds apart between 0 degrees and 50 degrees latitude, and spaced 3 arc seconds apart in latitude and 6 arc seconds apart in longitude between 50 degrees and 60 degrees latitude.

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 meters or the relief is greater than 15 meters. The data are processed in one degree by one degree "cells". The edges of cell are matched with the edges of adjacent cells to assure continuity.

In addition to voids due to shadows and layover and poor reflective properties of the Earth's surface, there are occasional floating islands of data, unregistered vertically, due to phase unwrapping errors. On the whole, the SRTM DTED absolute height accuracy is significantly better than the 16 meters (90 % confidence) specification for the mission and the data are 95% complete over the collection area.
Source_Produced_Citation_Abbreviation:
USGS/EROS SRTM DTED
Process_Step:
Process_Description:
The following steps were performed by ESRI: Ordered and received the Shuttle Radar Topography Mission DTEDr Level 1 (3-arc second) elevation data on thirteen DVDs (14,277 DTEDr cells) from the U.S. Geological Survey Center for Earth Resource Observation and Science (EROS).
 
Converted each one degree by one degree elevation DTED cell from DTED format to ESRI Grid format. Created a NoData ESRI Grid from each elevation ESRI Grid; this was used to identify which elevation ESRI Grids required void fill-ins. Within certain elevation ESRI Grids that contained voids, some voids existed in the water/land "interface" (i.e. a void that spatially spanned across water and land). The assumed water areas within this type of void were manually identified and the elevation ESRI Grid pixels were set to a constant elevation value that was appropriate for the area. 
 
Filled all voids within the one degree by one degree elevation ESRI Grids. The primary method used to fill voids was the Delta Surface Fill (DSF) method (see the article "Filling SRTM Voids: The Delta Surface Fill Method" by Greg Grohman, George Kroenung and John Strebeck in the March 2006 issue of "Photogrammetric Engineering & Remote Sensing"). The GTOPO30 elevation dataset was used as the fill-in source. How the DSF method differs from other interpolation methods is that with the DSF method the voids are not filled by interpolating through the voids in the elevation, but rather interpolating through the voids within a delta surface, which is the difference between the surface requiring fill (SRTM) and the fill-in source (GTOPO30). The interpolated surface is used to adjust the GTOPO30 fill-in source, which values are then used to fill-in the voids within the SRTM elevation surface. In situations where there were no GTOPO30 pixels in the area of a void, the DSF method was unable to fill these voids. In these cases a secondary method was used to the fill the voids. This involved interpolating through the voids in the elevation values in the output surface from the DSF method.
 
Mosaicked all SRTM elevation ESRI Grids (void-filled and those that did not require fill-in) into a single ArcSDE 9.1 raster dataset. NOTE: There were six ESRI Grids where the extent exceeded the -180 longitude; these ESRI Grids were clipped at the -180 longitude prior to mosaicking. The process of mosaicking created NoData areas in the elevation raster dataset in the area of two inland water bodies (elevation not 0 meters). Created and loaded constant elevation ESRI Grids into the ArcSDE elevation raster dataset for the following areas (constant elevation noted): Lake Superior (179 meters) and Caspian Sea (-29 meters).
 
The SRTM data in DTED Level 1 format did not include data for the cell E012N24 (South West Libya). In order to fill this area with elevation data, the GTOPO30 dataset was processed in the following manner: Resampled to match SRTM elevation ESRI Grid cellsize; Smoothed using a 9 by 9 rectangular focalmean function; created a delta ESRI Grid by subtracting the resampled and smoothed GTOPO30 ESRI Grid from an ESRI Grid containing the five rows and columns worth of SRTM data surrounding the E012N24 cell; adjusted the resampled and smoothed GTOPO30 ESRI Grid based on the statistical mean of the delta ESRI Grid; clipped the adjusted GTOPO30 ESRI Grid to match the missing extent of elevation data; converted the adjusted GTOPO30 ESRI Grid from floating point to integer; and loaded the resultant ESRI Grid into the ArcSDE 9.1 elevation raster dataset. Calculated raster statistics on the ArcSDE 9.1 elevation raster dataset.
 
Extracted data from the ArcSDE 9.1 elevation raster dataset into the six ESRI Grids that represent the final delivery extents. For each of these elevation ESRI Grids (except for the South East ESRI Grid), set the NoData pixels to have a value of 0 (these pixels are in the areas formed by the mosaicking of the SRTM elevation ESRI Grids and are located in the ocean). The South East ESRI Grid contained islands that were located along the 180 longitude, but because of the differing cell alignment above/below 50 degrees north/south latitude within the original DTED data, the mosaicked data had the last column populated with NoData. For this South East ESRI Grid set all NoData pixels to 0 except for the last column; for the last column used the focalmean function to add back land values.
 
Converted the six elevation ESRI Grids to 16-bit signed integer JPEG 2000 raster datasets using a compression quality of 5. Calculated raster statistics for the elevation JPEG 2000 raster datasets. Created ArcGISr layer files (.lyr).
Source_Used_Citation_Abbreviation:
USGS/EROS SRTM DTED
Source_Used_Citation_Abbreviation:
ESRI Data & Maps 2005
Process_Date: 20060726
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Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 74401
Column_Count: 119999
Vertical_Count: 1
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Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.000000
Longitude_Resolution: 0.000000
Geographic_Coordinate_Units: Decimal degrees
Planar:
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 0.000833
Ordinate_Resolution: 0.000833
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: WGS84 Earth Gravitational Model (EGM 96)
Altitude_Distance_Units: meters
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: ESRI; ESRI International Distributors
Contact_Address:
Address_Type: mailing and physical address
Address:
380 New York Street
City: Redlands
State_or_Province: California
Postal_Code: 92373-8100
Country: USA
Contact_Voice_Telephone: 800-447-9778
Contact Instructions:
In the United States, contact the ESRI Telebusiness staff at 800-447-9778 for more information about our software and data.

Outside the United States, please direct all inquiries to your local ESRI International Distributor.  This information can be found at http://gis.esri.com/intldist/contactint.cfm.
Resource_Description: Offline Data
Distribution_Liability:
See use constraints.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: JPEG 2000
Format_Specification:
The JP2 file contains the image data. The AUX file contains auxiliary information (optional) (i.e. information from ArcGIS, which the JP2 format cannot store natively). The XML file (*.jp2.xml) contains the metadata describing the data set (optional).
File_Decompression_Technique: JPEG2000
Digital_Transfer_Option:
Offline_Option:
Offline_Media: DVD-ROM
Recording_Capacity:
Recording_Density: 7.95
Recording_Density_Units: GB (gigabytes)
Recording_Format: UDF (Universal Disc Format)
Fees: Software purchase price
Ordering_Instructions:
ESRI Data & Maps is available only as part of ESRIr software.
Technical_Prerequisites:
To use this data requires software that supports JPEG 2000 files.
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Metadata_Reference_Information:
Metadata_Date: 20060915
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: ESRI
Contact_Person: Data Team
Contact_Address:
Address_Type: mailing and physical address
Address:
380 New York Street
City: Redlands
State_or_Province: California
Postal_Code: 92373-8100
Country: USA
Contact_Voice_Telephone: 909-793-2853
Contact_Facsimile_Telephone: 909-793-5953
Contact_Electronic_Mail_Address: info@esri.com
Hours_of_Service: 7:00 a.m.-5:30 p.m. Pacific time, Monday-Friday
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: http://www.esri.com/metadata/esriprof80.html
Profile_Name: ESRI Metadata Profile
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