DEM, Upper St. Johns River Basin North

Metadata:

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

Identification_Information:

Citation:

Citation_Information:

Originator: U.S. Geological Survey

Publication_Date: 201009

Publication_Time: Unknown

Title: DEM, Upper St. Johns River Basin North

Geospatial_Data_Presentation_Form: SDE raster digital data

Online_Linkage:

Server=earth; Service=esri_sde; User=gislib; Version=SDE.DEFAULT

Description:

Abstract:

The USGS SJRMWD Project covers 563 square miles in Brevard, Orange, and Osceola Counties in Florida. Dewberry produced hydro flattened DEMs for 628 tiles (5000 ft x 5000 ft) covering this area. The hydro flattened DEMs were created with a 10 ft cell size and are created from the class 2, ground, LiDAR points and 3D breaklines that were collected to project specifications. This raster is a mosaic of the 628 tiles with elevation values in feet.* Important note: The SJRWMD processed this dataset to have vertical units of feet and the SJRWMD's standard UTM spatial reference. See Process Steps for additional information.

Purpose:

The hydro flattened Digital Elevation Models (DEMs) provide a bare earth elevation surface that depicts the ground surface with flattened inland water features. These DEMs are not hydro enforced or hydro conditioned. These DEMs are created to the USGS National Geospatial Program Base LiDAR pecifications, version 12.

Supplemental_Information:

A complete description of this dataset is available in the Final Project Report submitted to the USGS.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20100415

Ending_Date: 20100426

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -81.129371

East_Bounding_Coordinate: -80.704804

North_Bounding_Coordinate: 28.790504

South_Bounding_Coordinate: 28.087704

Keywords:

Theme:

Theme_Keyword_Thesaurus: None

Theme_Keyword: DTM

Theme_Keyword: Elevation

Theme_Keyword: Lidar

Theme_Keyword: LAS

Theme_Keyword: DEM

Theme_Keyword: Hydro Flattened

Theme_Keyword: Breaklines

Place:

Place_Keyword_Thesaurus: None

Place_Keyword: Florida

Place_Keyword: St. Johns River Water Management District

Place_Keyword: Orange County

Place_Keyword: Osceola County

Place_Keyword: Brevard County

Access_Constraints: None

Use_Constraints:

This data was produced for the USGS according to specific project requirements. This information is provided "as is". Further documentation of this data can be obtained by contacting: USGS/NGTOC, 1400 Independence Road, Rolla, MO 65401. Telephone (573) 308-3579.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: USGS

Contact_Position: USGS NGTOC

Contact_Address:

Address_Type: mailing and physical address

Address: 1400 Independence Road

City: Rolla

State_or_Province: MO

Postal_Code: 65401

Country: USA

Contact_Voice_Telephone: (573) 308-3579

Contact_Electronic_Mail_Address: jmurphey@usgs.gov

Native_Data_Set_Environment:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3500

Data_Quality_Information:

Logical_Consistency_Report: Data covers the tile scheme provided for the project area.

Completeness_Report:

A visual qualitative assessment was performed to ensure data completeness and full tiles. No void or missing data exists.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

The DEMs are derived from the source LiDAR and 3D breaklines created from the LiDAR. Horizontal accuracy is not performed on the DEMs or breaklines. Lidar source compiled to meet 3.5 foot horizontal accuracy.

Quantitative_Horizontal_Positional_Accuracy_Assessment:

Horizontal_Positional_Accuracy_Value: 3.5 feet

Horizontal_Positional_Accuracy_Explanation:

The DEMs are derived from the source LiDAR and 3D breaklines created from the LiDAR. Horizontal accuracy is not performed on the DEMs, breaklines, or LiDAR. LiDAR vendors perform calibrations on the LiDAR sensor and compare data to adjoing flight lines to ensure LiDAR meets the 3.5 ft horizontal accuracy standard at the 95% confidence level. Please see the final project report delivered to the USGS for more details.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

The DEMs are derived from the source LiDAR and 3D breaklines created from the LiDAR. Vertical accuracy is not tested on the DEMs.
The vertical accuracy of the LiDAR was tested by Dewberry with 60 independent survey checkpoints. The survey checkpoints were evenly distributed throughout the project area and can be categorized into three different landcover types according to the following breakdown:
bare earth and low grass: 20 checkpoints vegetation: 35 checkpoints urban: 5 checkpoints
Bare earth and low grass checkpoints were used to compute the Fundamental Vertical Accuracy (FVA). Project specifications required a FVA of 1.00 ft (30 cm) based on a RMSEz (0.50 ft/15 cm) x 1.9600. All checkpoints were used to compute the Consolidated Vertical Accuracy (CVA). Project specifications required a CVA of 1.00 ft (30 cm) based on the 95th percentile.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 0.56 feet

Vertical_Positional_Accuracy_Explanation:

The DEMs are derived from the source LiDAR and 3D breaklines created from the LiDAR. Vertical accuracy is not tested on the DEMs.
Based on the vertical accuracy testing conducted by Dewberry, using NSSDA and FEMA methodology, vertical accuracy at the 95% confidence level (called Accuracyz) is computed by the formula RMSEz x 1.9600. The dataset for the USGS SJRWMD project satisfies the criteria: Lidar dataset tested 0.56 ft vertical accuracy at 95% confidence level in open terrain, based on open terrain RMSEz (0.29 ft) x 1.9600.
Based on the vertical accuracy testing conducted by Dewberry, using NDEP and ASPRS methodology, consolidated vertical accuracy at the 95% confidence level is computed using the 95th percentile method. The dataset for the USGS SJRWMD project satisfies the criteria: Lidar dataset tested 0.76 ft vertical accuracy at 95% confidence level in all land cover categories combined.

Lineage:

Process_Step:

Process_Description:

Terrapoint used their Optech ALTM 3100EA LiDAR sensor to collect the data for the USGS SJRWMD project. This sensor was located within a Piper Navaho aircraft.
Nine flight missions were required to obtain data over the entire project area. Flightlines were flown in a North-South orientation to optimize flying time in regards to the project layout. A combination of Sokkia GSR 2600 and NovAtel DL-4+ dual-frequency GPS receivers were used to support the airborne operations of this survey and to establish the GPS control network. Terrapoint used four existing published survey monuments were used to control all flight missions and kinematic and static ground surveys.
Airborne GPS kinematic data was processed on-site using GrafNav kinematic On-The-Fly (OTF) software. Flights were flown with a minimum of 6 satellites in view (13o above the horizon) and with a PDOP of better than 3. Distances from base station to aircraft were kept to a maximum of 24km. For all flights, the GPS data can be classified as excellent, with GPS residuals of 3-5 cm average or better but no larger than 10 cm being recorded.
The initial step of calibration is to verify availability and status of all needed GPS and Laser data against field notes and compile any data if not complete. Subsequently the mission points are output using Optech's Dashmap, initially with default values from Optech or the last mission calibrated for system. The initial point generation for each mission calibration is verified within Microstation/Terrascan for calibration errors. If a calibration error greater than specification is observed within the mission, the roll pitch and scanner scale corrections that need to be applied are calculated. The missions with the new calibration values are regenerated and validated internally once again to ensure quality. All missions are validated against the adjoining missions for relative vertical biases and collected GPS kinematic validation points for absolute vertical accuracy purposes. On a project level, a supplementary coverage check is carried out, to ensure no data voids unreported by Field Operations are present.

Source_Used_Citation_Abbreviation: Airborne Global Positioning System Data

Source_Used_Citation_Abbreviation: Inertial Measurement Unit

Process_Date: 201004

Source_Produced_Citation_Abbreviation: Calibrated LiDAR Point Cloud LAS 1.2 format

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Terrapoint USA

Contact_Address:

Address_Type: mailing and physical address

Address: 251216 Grogan's Park Drive

City: The Woodlands

State_or_Province: Texas

Postal_Code: 77380

Country: USA

Contact_Voice_Telephone: 1-877-999-7687

Contact_Facsimile_Telephone: 1-281-296-0869

Hours_of_Service: Monday to Friday, 8 - 5, CST

Process_Step:

Process_Description:

Dewberry utilizes a variety of software suites for inventory management, classification, and data processing. All LiDAR related processes begin by importing the data into the GeoCue task management software. GeoCue allows the data to retain its delivered tiling scheme (5000 ft by 5000 ft). The tiled data is then opened in Terrascan where Dewberry uses proprietary ground classification routines to remove any non-ground points and generate an accurate ground surface. The ground routine consists of three main parameters (building size, iteration angle, and iteration distance); by adjusting these parameters and running several iterations of this routine an initial ground surface is developed. The building size parameter sets a roaming window size. Each tile is loaded with neighboring points from adjacent tiles and the routine classifies the data section by section based on this roaming window size. The second most important parameter is the maximum terrain angle, which sets the highest allowed terrain angle within the model. Once the ground routine has been completed a manual quality control routine is done using hillshades, cross-sections, and profiles within the Terrasolid software suite. After this QC step, a peer review and supervisor manual inspection is completed on a percentage of the classified tiles based on the project size and variability of the terrain. After the ground classification corrections were completed, the dataset was processed through a water classification routine that utilizes breaklines compiled by Dewberry to automatically classify hydrographic features. The water classification routine selects ground points within the breakline polygons and automatically classifies them as class 9, water. During this water classification routine, points which are in close proximity (2 ft) to the hydrographic features are moved to class 10, an ignored ground. In addition to classes 1, 2, 9, and 10, St. Johns allows for a Class 7, noise points. This class was only used if needed when points could manually be identified as low/high points. The fully classified dataset is then processed through Dewberry's comprehensive quality control program.
The data was classified as follows: Class 1 = Unclassified. This class includes vegetation, buildings, noise etc. Class 2 = Ground Class 7= Noise Class 9 = Water Class 10= Ignored Ground
The LAS header information was verified to contain the following: Class (Integer) GPS Week Time (0.0001 seconds) Easting (0.01 foot) Northing (0.01 foot) Elevation (0.01 foot) Echo Number (Integer 1 to 4) Echo (Integer 1 to 4) Intensity (8 bit integer) Flight Line (Integer) Scan Angle (Integer degree)

Source_Used_Citation_Abbreviation: Calibrated LiDAR Point Cloud LAS 1.2 format

Process_Date: 201008

Source_Produced_Citation_Abbreviation: Final LiDAR datasets with USGS-ARRA classifications

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Keith Patterson

Contact_Organization: Dewberry - Geospatial Services Group

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 1000 N. Ashley Drive, Suite 801

City: Tampa

State_or_Province: FL

Postal_Code: 33602

Country: USA

Contact_Voice_Telephone: 813.225.1325

Contact_Facsimile_Telephone: 813.225.1385

Contact_Electronic_Mail_Address: kpatterson@dewberry.com

Hours_of_Service: 8:00 - 5:00 EST

Process_Step:

Process_Description:

Dewberry used GeoCue software to develop raster stereo models from the LiDAR intensity. The raster resolution was 1ft.

Source_Used_Citation_Abbreviation: Final LiDAR datasets with USGS-ARRA classifications

Process_Date: 201006

Source_Produced_Citation_Abbreviation: Lidar Intensity Stereopairs

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Keith Patterson

Contact_Organization: Dewberry - Geospatial Services Group

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 1000 N. Ashley Drive, Suite 801

City: Tampa

State_or_Province: FL

Postal_Code: 33602

Country: USA

Contact_Voice_Telephone: 813.225.1325

Contact_Facsimile_Telephone: 813.225.1385

Contact_Electronic_Mail_Address: kpatterson@dewberry.com

Hours_of_Service: 8:00 - 5:00 EST

Process_Step:

Process_Description:

LiDAR intensity stereopairs were viewed in 3-D stereo using Socet Set for ArcGIS softcopy photogrammetric software. The breaklines are collected directly into an ArcGIS file geodatabase to ensure correct topology. The LiDARgrammetry was performed under the direct supervision of an ASPRS Certified Photogrammetrist. The breaklines were stereo-compiled in accordance with the Data Dictionary.
Both Inland Lakes and Ponds and Inland Streams and Rivers were collected according to specifications for the USGS SJRWMD Project.

Source_Used_Citation_Abbreviation: Lidar Intensity Stereopairs

Process_Date: 201007

Source_Produced_Citation_Abbreviation: 3D breaklines

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Keith Patterson

Contact_Organization: Dewberry - Geospatial Services Group

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 1000 N. Ashley Drive, Suite 801

City: Tampa

State_or_Province: FL

Postal_Code: 33602

Country: USA

Contact_Voice_Telephone: 813.225.1325

Contact_Facsimile_Telephone: 813.225.1385

Contact_Electronic_Mail_Address: kpatterson@dewberry.com

Hours_of_Service: 8:00 - 5:00 EST

Process_Step:

Process_Description:

Class 2, ground, LiDAR points are exported from the LAS files into an Arc Geodatabase (GDB) in multipoint format. The 3D breaklines, Inland Lakes and Ponds and Inland Streams and Rivers, are imported into the same GDB. An ESRI Terrain is generated from these inputs. The surface type of each input is as follows:
Ground Multipoint: Masspoints Inland Lakes and Ponds: Hard Replace Inland Streams and Rivers: Hard Line

Source_Used_Citation_Abbreviation: Lidar Ground Points, Class 2

Source_Used_Citation_Abbreviation: 3D Breaklines

Process_Date: 201008

Source_Produced_Citation_Abbreviation: ESRI Terrain

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Keith Patterson

Contact_Organization: Dewberry - Geospatial Services Group

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 1000 N. Ashley Drive, Suite 801

City: Tampa

State_or_Province: FL

Postal_Code: 33602

Country: USA

Contact_Voice_Telephone: 813.225.1325

Contact_Facsimile_Telephone: 813.225.1385

Contact_Electronic_Mail_Address: kpatterson@dewberry.com

Hours_of_Service: 8:00 - 5:00 EST

Process_Step:

Process_Description:

The ESRI Terrain is converted to rasters. The rasters are created to pre-defined extents so that multiple rasters are created over the project area. Creating multiple rasters rather than one large raster over a large project area makes the data more maneageable to work with. The rasters are created with 50 ft of overlap. This allows us to ensure seamless coverage and edge-matching in the final tiled product. These rasters were created with a 10 foot cell size. USGS specifications state final DEMs must be no greater than 10 feet or 3 meters. The final DEM cell size must be evenly divided into the final tile grid for correct pixel alignment and edge-matching. As the tile grid is 5000 ft x 5000 ft, a cell size of 10 ft was used for the final DEMs.

Source_Used_Citation_Abbreviation: ESRI Terrain

Process_Date: 201008

Source_Produced_Citation_Abbreviation: Non-Tiled Hydro Flattened DEMs

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Keith Patterson

Contact_Organization: Dewberry - Geospatial Services Group

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 1000 N. Ashley Drive, Suite 801

City: Tampa

State_or_Province: FL

Postal_Code: 33602

Country: USA

Contact_Voice_Telephone: 813.225.1325

Contact_Facsimile_Telephone: 813.225.1385

Contact_Electronic_Mail_Address: kpatterson@dewberry.com

Hours_of_Service: 8:00 - 5:00 EST

Process_Step:

Process_Description:

The DEMs that are created over large areas are reviewed in ArcGIS with hillshades. Hillshades allow the analyst to view the DEMs in 3D and to more efficiently locate and identify potential issues. The first review is done on the area DEMs as this increases the efficiency of any corrections that may be performed. Performing corrections on area DEMs allows the analyst to perform corrections on multiple tiles at once and helps prevent errors from occurring along individual tile seamlines. Analysts review the area DEMs for incorrect water elevations and artifacts that are introduced during the raster creation process.

Source_Used_Citation_Abbreviation: Non-Tiled Hydro Flattened DEMs

Process_Date: 201008

Source_Produced_Citation_Abbreviation: Corrected and Final Non-Tiled Hydro Flattened DEMs

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Keith Patterson

Contact_Organization: Dewberry - Geospatial Services Group

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 1000 N. Ashley Drive, Suite 801

City: Tampa

State_or_Province: FL

Postal_Code: 33602

Country: USA

Contact_Voice_Telephone: 813.225.1325

Contact_Facsimile_Telephone: 813.225.1385

Contact_Electronic_Mail_Address: kpatterson@dewberry.com

Hours_of_Service: 8:00 - 5:00 EST

Process_Step:

Process_Description:

The corrected and final area DEMs are clipped to individual tiles. Dewberry uses a proprietary tool that clips the area DEMs to each tile located within the final Tile Grid, names the clipped DEM to the Tile Grid Cell name, and verifies that final extents are correct. All individual tiles are loaded into Global Mapper for the last review. During this last review, an analsyt checks to ensure full, complete coverage, no issues along tile boundaries, tiles seamlessly edge-match, and that there are no remaining processing artifacts in the dataset.

Source_Used_Citation_Abbreviation: Corrected and Final Non-Tiled Hydro Flattened DEMs

Process_Date: 201008

Source_Produced_Citation_Abbreviation: Final Tiled Hydro Flattened DEMs

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Keith Patterson

Contact_Organization: Dewberry - Geospatial Services Group

Contact_Position: Project Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 1000 N. Ashley Drive, Suite 801

City: Tampa

State_or_Province: FL

Postal_Code: 33602

Country: USA

Contact_Voice_Telephone: 813.225.1325

Contact_Facsimile_Telephone: 813.225.1385

Contact_Electronic_Mail_Address: kpatterson@dewberry.com

Hours_of_Service: 8:00 - 5:00 EST

Process_Step:

Process_Description:

The raster 's elevation values were converted from meters to feet by multiplying the value of each cell by 3.28083333333

Process_Date: 20101015

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: SJRWMD

Process_Step:

Process_Description:

The raster was projected/transformed from geographic coordinates (latitude/longitude) NAD 1983 to UTM zone 17N HARN meters. Bilinear interpolation was used and the cell size set to 3 meters (an approximation of 1/9 arc-second).

Process_Date: 20101015

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: SJRWMD

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Pixel

Row_Count: 25941

Column_Count: 13812

Vertical_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: row and column

Coordinate_Representation:

Abscissa_Resolution: 3.000000

Ordinate_Resolution: 3.000000

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: D_North_American_1983_HARN

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257222

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: North American Vertical Datum of 1988

Altitude_Distance_Units: feet

Altitude_Encoding_Method:

Explicit elevation coordinate included with horizontal coordinates

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: USGS

Contact_Position: USGS NGTOC

Contact_Address:

Address_Type: mailing and physical address

Address: 1400 Independence Road

City: Rolla

State_or_Province: MO

Postal_Code: 65401

Country: USA

Contact_Voice_Telephone: (573) 308-3579

Contact_Electronic_Mail_Address: jmurphey@usgs.gov

Resource_Description: Downloadable Data

Distribution_Liability:

This data was produced for the USGS according to specific project requirements. This information is provided "as is". Further documentation of this data can be obtained by contacting: USGS/NGTOC, 1400 Independence Road, Rolla, MO 65401. Telephone (573) 308-3579.

Metadata_Reference_Information:

Metadata_Date: 20101015

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: USGS

Contact_Person: REQUIRED: The person responsible for the metadata information.

Contact_Position: USGS NGTOC

Contact_Address:

Address_Type: mailing and physical address

Address: 1400 Independence Road

City: Rolla

State_or_Province: MO

Postal_Code: 65401

Country: USA

Contact_Voice_Telephone: (573) 308-3579

Contact_Electronic_Mail_Address: jmurphey@usgs.gov

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time