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High Accuracy Elevation Data - truck

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Metadata:


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: <https://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 <https://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: <https://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: <https://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: <https://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: <https://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

This page is <https://sofia.usgs.gov/metadata/sflwww/HAED_truck.html>

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