High Accuracy Elevation Data - truck

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: Greg Desmond

Publication_Date: 200710

Title: High Accuracy Elevation Data - truck

Geospatial_Data_Presentation_Form: text files, shapefiles

Online_Linkage: <http://sofia.usgs.gov/exchange/desmond/desmondelev.html>

Description:

Abstract:

The High Accuracy Elevation Data Project collected elevation data (meters) on a 400 meter topographic grid with a vertical accuracy of +/- 15 centimeters to define the topography in South Florida. The data are referenced to the horizontal datum North American Datum 1983 (NAD 83) and the vertical datum North American Vertical Datum 1988 (NAVD 88). The High Accuracy Elevation Data Project began with a pilot study in FY 1995 to determine if the then state-of-the-art GPS technology could be used to perform a topographic survey that would meet the vertical accuracy requirements of the hydrologic modeling community. The initial testing platform was from a truck and met the accuracy requirements. Data were collected in areas near Homestead, Florida. The data are available for the areas shown on the USGS High Accuracy Elevation Data graphic at <http://sofia.usgs.gov/exchange/desmond/desmondelev.html>.

Purpose:

These data are from topographic surveys to collect and provide elevation data to parameterize hydrologic and ecological numerical simulation models that were being developed for ecosystem restoration activities. Surveying services were also rendered to provide vertical reference points for numerous water level gauges.

Modeling of sheet flow and water surface levels in the wetlands of South Florida is very sensitive to changes in elevation due to the expansive and extremely low relief terrain. Hydrologists have determined minimum vertical accuracy requirements for the elevation data for use as input to hydrologic models. As a result, elevation data with a vertical accuracy specification of +/-15 centimeters (cm) relative to the North American Vertical Datum of 1988 (NAVD88) were collected in critical areas using state-of-the-art differential global positioning system (GPS) technology and data processing techniques.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 1995

Ending_Date: 1996

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -80.625

East_Bounding_Coordinate: -80.25

North_Bounding_Coordinate: 25.625

South_Bounding_Coordinate: 25.375

Keywords:

Theme:

Theme_Keyword_Thesaurus: none

Theme_Keyword: High accuracy elevation data

Theme_Keyword: mapping

Theme_Keyword: digital elevation data

Theme_Keyword: DEM

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category

Theme_Keyword: elevation

Theme_Keyword: 006

Place:

Place_Keyword_Thesaurus:

Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, DC, National Institute of Standards and Technology

Place_Keyword: United States

Place_Keyword: US

Place:

Place_Keyword_Thesaurus:

U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, DC, NIST

Place_Keyword: Florida

Place_Keyword: FL

Place:

Place_Keyword_Thesaurus:

Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, FIPS 6-3, Washington, DC, National Institute of Standards and Technology

Place_Keyword: Miami-Dade County

Place:

Place_Keyword_Thesaurus: USGS Geographic Names Information System

Place_Keyword: Goulds

Place_Keyword: Perrine

Place_Keyword: Grossman Hammock

Place_Keyword: Royal Palm Ranger Station

Place:

Place_Keyword_Thesaurus: none

Place_Keyword: South East Coast

Access_Constraints: none

Use_Constraints:

None. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Bob Glover

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing address

Address: 521 National Center

City: Reston

State_or_Province: VA

Postal_Code: 20192

Country: USA

Contact_Voice_Telephone: 703 648-5056

Contact_Electronic_Mail_Address: rglover@usgs.gov

Browse_Graphic:

Browse_Graphic_File_Name: <http://sofia.usgs.gov/exchange/desmond/desmondelev.html>

Browse_Graphic_File_Description: USGS High Accuracy Elevation Data

Browse_Graphic_File_Type: GIF

Browse_Graphic:

Browse_Graphic_File_Name: <http://sofia.usgs.gov/exchange/desmond/atlas/>

Browse_Graphic_File_Description:

USGS HAED Electronic Atlas (view data by USGS 24K topographic quads)

Browse_Graphic_File_Type: GIF

Data_Set_Credit:

Data collection done by Charles Henkle, Gordon Shupe, Bob Glover, Ed Cyran, and Greg Desmond of the USGS and contractors. Other project personnel include Vince Caruso, Gary Freeman, and Susan Price.

Native_Data_Set_Environment:

compressed ESRI shapefile (.zip) and comma-separated value file (.csv)

Data_Quality_Information:

Logical_Consistency_Report:

Grossman Hammock and Royal Palm Ranger Station are included in both the helicopter AHF & airboat and truck datasets

Completeness_Report:

All verified and accepted data points are included in the files for each area

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Horizontal positions are established by GPS observations and are referenced to the North American Datum of 1983 (NAD83). The desired horizontal accuracy is +/- 15 centimeters. This level of accuracy is consistent with GPS differential techniques which use two stations - a high-quality dual-frequency GPS receiver base station and a roving GPS station. The density and accuracy of a given GPS data observation varies from a few meters to a few centimeters according to the Position Dilution of Precision (PDOP) in the study area. Generally if the PDOP is observed to be excessive, data collection is discontinued or the data are discarded. The PDOP is an indicator of the positional accuracy of the GPS that be can derived from the current GPS satellite geometry, which varies continuously. Generally the smaller the PDOP number, the higher the data quality. The PDOP is a permanent part of the recorded data and is also included in the post processing procedures during reduction of the GPS observations to NAD 83. Where possible, the GPS base station has an ellipsoid height to an accuracy of two centimeters relative to the Continuously Operating Reference Stations (CORS) or the High Accuracy Reference Network (HARN), both operated by the National Geodetic Survey (NGS).

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

For all elevation data the vertical accuracy specification is +/- 15 centimeters and is referenced to NAVD 1988.

This elevation data is intended primarily for use in hydrological modeling. It is collected as high accuracy, "bare earth" ground elevation. That is, the data are restricted to ground elevations only. "Bare earth" in the Everglades swamp environment is generally considered to be the layer of "muck" which will support a one pound weight on a bearing surface of approximately 5.3 square inches (2.6 inch circle). In non-swamp areas it is actual bare ground.

Lineage:

Process_Step:

Process_Description:

The process for creating digital elevation files consisted of the following steps:

1. Collection of GPS XYZ points in map area 3 during the pilot study started in FY 1995.

2. The GPS data were transformed from NAD83 geographic X, Y coordinates and NAVD88 elevation Z valuse to NAD83 UTM X, Y and NAVD88 Z coordinates via "Corpscon for Windows" from the U.S. Army Corps of Engineers. <http://crunch.tec.army.mil/software/corpscon/corpscon.html>

3. The coordinate data were imported into a geographic information system to create multiple geospatial data formats.

4. The ascii text file containing 1925 data records was aggregated and reformatted using custom shell scripts.

5. The shapefile-associated .dbf file was opened in MS Excel and saved as the comma-separated value file which also is available for download

Process_Date: 200708

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Susan D. Price

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing address

Address: 521 National Center

City: Reston

State_or_Province: VA

Postal_Code: 20192

Country: USA

Contact_Voice_Telephone: 703 648 6692

Contact_Electronic_Mail_Address: sprice@usgs.gov

Spatial_Data_Organization_Information:

Indirect_Spatial_Reference: south east coast of Florida

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Entity point

Point_and_Vector_Object_Count: 1925

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: Universal Transverse Mercator

Universal_Transverse_Mercator:

UTM_Zone_Number: 17

Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9996

Longitude_of_Central_Meridian: -81

Latitude_of_Projection_Origin: 0

False_Easting: 500000

False_Northing: 0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: Coordinate Pair

Coordinate_Representation:

Abscissa_Resolution: 400

Ordinate_Resolution: 400

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137

Denominator_of_Flattening_Ratio: 298.257

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: North American Vertical Datum of 1988

Altitude_Resolution: .01

Altitude_Distance_Units: meters

Altitude_Encoding_Method:

Explicit elevation coordinate included with horizontal coordinates

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: ELEV_M

Entity_Type_Definition: ground surface elevation in meters

Entity_Type_Definition_Source: USGS

Detailed_Description:

Entity_Type:

Entity_Type_Label: X_UTM

Entity_Type_Definition: UTM X coordinate in meters for the data collection point

Entity_Type_Definition_Source: USGS

Detailed_Description:

Entity_Type:

Entity_Type_Label: Y_UTM

Entity_Type_Definition: UTM Y coordinate in meters for the data collection point

Entity_Type_Definition_Source: USGS

Detailed_Description:

Entity_Type:

Entity_Type_Label: QUAD_NAME

Entity_Type_Definition:

The name of the USGS 1:24, 000-scale topographic quadrangle in which the point falls

Entity_Type_Definition_Source: USGS

Detailed_Description:

Entity_Type:

Entity_Type_Label: SUR_METHOD

Entity_Type_Definition: type of surveying method - truck

Entity_Type_Definition_Source: USGS

Distribution_Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Heather S.Henkel

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing address

Address: 600 Fourth St. South

City: St. Petersburg

State_or_Province: FL

Postal_Code: 33701

Country: USA

Contact_Voice_Telephone: 727 803-8747 ext 3028

Contact_Facsimile_Telephone: 727 803-2030

Contact_Electronic_Mail_Address: hhenkel@usgs.gov

Resource_Description: Truck

Distribution_Liability: No warrantees are implied or explicit for the data

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: ASCII

Format_Version_Date: 1985

Format_Specification: .csv

Format_Information_Content: comma-separated values for elevations in map area 3

Transfer_Size: 0.08

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name: <http://sofia.usgs.gov/exchange/desmond/desmondelev.html>

Access_Instructions: Files may be downloaded from the SOFIA website

Digital_Form:

Digital_Transfer_Information:

Format_Name: zip

Format_Version_Number: unknown

Format_Specification: shp.zip

Format_Information_Content:

ArcGIS shapefile and associated files for the elevations collected by truck

File_Decompression_Technique: file must be unzipped before use

Transfer_Size: 0.051

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name: <http://sofia.usgs.gov/exchange/desmond/desmondelev.html>

Access_Instructions: Data may be downloaded from the SOFIA website

Fees: none

Metadata_Reference_Information:

Metadata_Date: 20071024

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Heather Henkel

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing and physical address

Address: 600 Fourth Street South

City: St. Petersburg

State_or_Province: FL

Postal_Code: 33701

Country: USA

Contact_Voice_Telephone: 727 803-8747 ext 3028

Contact_Facsimile_Telephone: 727 803-2030

Contact_Electronic_Mail_Address: sofia-metadata@usgs.gov

Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

U.S. Department of the Interior, U.S. Geological Survey
Comments and suggestions? Contact: Heather Henkel - Webmaster
Generated by mp version 2.8.18 on Wed Oct 24 14:54:29 2007