Identification_Information: Citation: Citation_Information: Originator: Greg Desmond Publication_Date: 200710 Title: High Accuracy Elevation Data Collection Project Geospatial_Data_Presentation_Form: text files, shapefiles Online_Linkage: http://sofia.usgs.gov/projects/elev_data/ 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. In some areas, the surveying was accomplished using airboats. Because access was a logistical problem with airboats, the USGS developed a helicopter-based instrument known as the Airborne Height Finder (AHF). All subsequent data collection used the AHF. Data were collected from the Loxahatchee National Wildlife Refuge, south through the Water Conservation Areas (1A, 2A, 2B, 3A, and 3B), Big Cypress National Park, the Everglades National Park, to the Florida Bay. Data were also collected in the Lake Okeechobee littoral zone. 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. The work was performed for Everglades ecosystem restoration purposes. The project started in 1995 and concluded in 2007. Purpose: This project performed regional 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 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: 2007 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -81.625 East_Bounding_Coordinate: -80.125 North_Bounding_Coordinate: 27.33 South_Bounding_Coordinate: 25 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: Broward County Place_Keyword: Collier County Place_Keyword: Miami-Dade County Place_Keyword: Monroe County Place_Keyword: Palm Beach County Place_Keyword: Glades County Place_Keyword: Hendry County Place_Keyword: Okeechobee County Place: Place_Keyword_Thesaurus: none Place_Keyword: Central Everglades Place_Keyword: South East Coast Place_Keyword: SW Big Cypress Place_Keyword: Cooper City SW Place_Keyword: Coral Springs NE Place_Keyword: East of Deem City Place_Keyword: East of Lone Palm Head Place_Keyword: Hialeah SW Place_Keyword: Lake Ingraham East Place_Keyword: Lake Ingraham West Place_Keyword: Loxahatchee NW Place_Keyword: Loxahatchee SE Place_Keyword: Loxahatchee SW Place_Keyword: North of Fiftymile Bend Place_Keyword: North of Fortymile Bend Place_Keyword: Royal Palm Ranger Station SE Place_Keyword: South of Coopertown Place_Keyword: South of Deem City Place_Keyword: West of Big Lake Place_Keyword: West of Deem City Place_Keyword: West of Pennsuco Place_Keyword: Whitewater Bay East Place_Keyword: Whitewater Bay West Place_Keyword: Greater Lake Okeechobee Place_Keyword: Cooper City NE Place_Keyword: Monroe Station NE Place_Keyword: North of Lone Palm Head Place_Keyword: South Miami NW Place_Keyword: West of Horseshoe Head Place_Keyword: North of Deem City Place_Keyword: Okeechobee NW Place_Keyword: Okeechobee SE Place_Keyword: Okeechobee SW Place_Keyword: Brighton SE Place_Keyword: Clewiston North Place_Keyword: Clewiston South Place_Keyword: Water Conservation Area 1 Place_Keyword: Water Conservation Area 2 Place_Keyword: Water Conservation Area 3 Place_Keyword: WCA1 Place_Keyword: WCA2 Place_Keyword: WCA3 Place: Place_Keyword_Thesaurus: USGS Geographic Names Information System Place_Keyword: Andytown Place_Keyword: Big Boy Lake Place_Keyword: Big Lostmans Bay Place_Keyword: Black Hammock Place_Keyword: Blackwater Sound Place_Keyword: Chekika Island Place_Keyword: Chokoloskee Place_Keyword: Coopertown Place_Keyword: Custard Apple Hammock Place_Keyword: Fiftymile Bend Place_Keyword: Flamingo Place_Keyword: Fortymile Bend Place_Keyword: Gator Hook Swamp Place_Keyword: Glades Place_Keyword: Goulds Place_Keyword: Grossman Hammock Place_Keyword: Harney River Place_Keyword: Homestead Place_Keyword: Horseshoe Head Place_Keyword: Indian Camp Creek Place_Keyword: Joe Bay Place_Keyword: Long Island Place_Keyword: Long Pine Key Place_Keyword: Lostmans River Ranger Station Place_Keyword: Lostmans Trail Place_Keyword: Madeira Bay Place_Keyword: Mahogany Hammock Place_Keyword: Melaleuka Head Place_Keyword: Monroe Station Place_Keyword: Ochopee Place_Keyword: Pa-Hay-Okee Lookout Tower Place_Keyword: Panther Mound Place_Keyword: Pavillion Key Place_Keyword: Pennsuco Place_Keyword: Royal Palm Ranger Station Place_Keyword: Shark Point Place_Keyword: Tarpon Bay Place_Keyword: Taylor Slough Place_Keyword: West Lake Place_Keyword: Shark River Island Place_Keyword: Shark Valley Lookout Tower Place_Keyword: Big Lake Place_Keyword: Gator Lake Place_Keyword: Greenacres City Place_Keyword: Lone Palm Head Place_Keyword: Loxahatchee Place_Keyword: University Park Place_Keyword: Okeechobee Place_Keyword: Lakeport Place_Keyword: Fisheating Bay Place_Keyword: Cochrans Pass Place_Keyword: Moore Haven Place_Keyword: Lake Harbor Place_Keyword: Belle Glade Place_Keyword: Pahokee Place_Keyword: California Slough Place_Keyword: Deem City Place_Keyword: Everglades City Place_Keyword: Plover Key Place_Keyword: Sandy Key Place_Keyword: Weavers Station Place_Keyword: West Dixie Bend Place_Keyword: Perrine Place_Keyword: Loxahatchee National Wildlife Refuge Place_Keyword: Big Cypress National Preserve Place_Keyword: Everglades National Park Place_Keyword: Florida Bay Place_Keyword: Alligator Bay 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: map showing areas of USGS High Accuracy Elevation Data collection 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), comma-separated value file (.csv), and compressed .csv as needed (.zip) Data_Quality_Information: Logical_Consistency_Report: not available 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 and around the Greater Everglades Region from the Loxahatchee National Wildlife Refuge, south through the Water Conservation Areas (1A, 2A, 2B, 3A, and 3B), Big Cypress National Preserve, the Everglades National Park, to the Florida Bay, and Lake Okeechobee Littoral Zone, and environs using multiple collection platforms: truck, airboat and helicopter-based Airborne Height Finder (AHF) developed by the USGS. 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. Multiple formats of the data were posted to the SOFIA website. 5. This process was repeated for each quad-based file of data collected by the surveyors during the 12 year life of the project. 6. The ASCII text files containing more than 62,000 data records were aggregated and reformatted using custom shell scripts. These data were imported into ArcGIS (version 9.1) to create the three shapefiles (Okee_v06.shp, HAED_v01.shp, Truck_v14.shp) available for download. 7. The associated .dbf files were opened in MS Excel and saved as the comma-separated values files which also are 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 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: 62185 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: VEG_FS Entity_Type_Definition: The vegetation observed by the surveyor at the data collection point - collection started in 2003 art the request of scientists. Vegetation types include Alligator Hole, Broadleaf Emergent, Cattail, Cypress, Floating Emergent, Hardwood, Lygodium, Melaleuca, Open Water, Palmetto, Pine, Sawgrass, Shrub, Slough, Tree Island, Wet Prairie, Wet Prairie/Slough, and Willow Shrub Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: SUR_METHOD Entity_Type_Definition: type of surveying method Entity_Type_Definition_Source: USGS Attribute: Attribute_Label: AHF Attribute_Definition: Airborne Height Finder - a helicopter-based instrument used to access data points Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: AHF Attribute: Attribute_Label: AIRBOAT Attribute_Definition: data collected using an airboat to access the data points Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: AIRBOAT Attribute: Attribute_Label: TRUCK Attribute_Definition: data collected using a truck to access the data points Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: TRUCK Detailed_Description: Entity_Type: Entity_Type_Label: SUR_INFO Entity_Type_Definition: Characters 1-5 are the file name used by the surveyor during data collection. Characters 6-8 are the Julian date of the data collection. Characters 9-10 are the year the data were collected. Character 11 is a blank space. Characters 12-19 represent the date the data were released for publication and archive after the data have been collected, processed, edited, quality controlled, and approved for release. Character 20 is "Y" which means the data can be released. This is not the date the data were collected. During the 12 year lifetime of the project, data points were released as individual files (see SUR_FILE attribute) to match the published USGS 7.5-minute topographic quadrangle footprint. If new data were added to the quadrangle, the revision date was modified for ALL points in the quadrangle to reflect the latest revision date. At the completion of data collection, the individual quad-based files were aggregated to create the larger files now available for download. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: SUR_FILE Entity_Type_Definition: file name used by the surveyor for internal data management purposes 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: Elevation Data Distribution_Liability: No warrantees are implied or explicit for the data Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ASCII Format_Version_Number: 1985 Format_Specification: csv Format_Information_Content: comma-separated values for elevations in each map area Transfer_Size: 4.5 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: csv.zip Format_Information_Content: comma-separated values for elevations in map area 2 File_Decompression_Technique: file must be unzipped before use Transfer_Size: 0.7 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://sofia.usgs.gov/exchange/desmond/desmondelev.html Access_Instructions: File 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 shapefiles and associated files for each map area File_Decompression_Technique: file must be unzipped before use Transfer_Size: 1.7 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 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