St Johns River Water Management 1.0 Meter LiDAR Survey Bare Earth DEM Tiles

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Digital Aerial Solutions. LLC.

Publication_Date: 20120629

Title:

St Johns River Water Management 1.0 Meter LiDAR Survey Bare Earth DEM Tiles

Geospatial_Data_Presentation_Form: remote-sensing image

Publication_Information:

Publication_Place: Tampa, FL

Publisher: Digital Aerial Solutions. LLC.

Larger_Work_Citation:

Citation_Information:

Originator: Digital Aerial Solutions. LLC.

Publication_Date: Unpublished Material

Publication_Time: Unknown

Title:

St Johns River Water Management LiDAR Survey Bare Earth DEM Tiles

Geospatial_Data_Presentation_Form: remote-sensing image

Description:

Abstract:

The Light Detection and Ranging (LiDAR) dataset is a survey of the St Johns River Water Management LiDAR Survey project area in north-central Florida and encompasses 800 square miles. The LiDAR point cloud was flown at a nominal post spacing of 1.0 meters for unobscured areas. The LiDAR data and derivative products produced are in compliance with the U.S. Geological Survey National Geospatial Program Guidelines and Base Specifications, Version 13-ILMF 2010. The flight lines were acquired by Digital Aerial Solutions, LLC. between April 2, 2012 and April 11, 2012. Derivative products from the aerial acquisition include: Raw point cloud data in LAS v1.2, classified point cloud data in LAS v1.2, bare earth surface tiles (raster DEM ESRI float GRID format), bare earth surface DEMs mosaic, control points, project report, and FGDC compliant XML metadata.

Purpose: Undetermined

Time_Period_of_Content:

Time_Period_Information:

Multiple_Dates/Times:

Single_Date/Time:

Calendar_Date: 20120402

Single_Date/Time:

Calendar_Date: 20120411

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: Unknown

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -83.281184

East_Bounding_Coordinate: -82.877849

North_Bounding_Coordinate: 30.382894

South_Bounding_Coordinate: 29.814971

Keywords:

Theme:

Theme_Keyword_Thesaurus: Digital Elevation Model

Theme_Keyword: elevation

Place:

Place_Keyword_Thesaurus: Site Location

Place_Keyword:

FY12 St Johns River Water Management 1.0 Meter LiDAR Survey area

Place:

Place_Keyword_Thesaurus: State

Place_Keyword: Florida

Place:

Place_Keyword_Thesaurus: Country

Place_Keyword: United States

Stratum:

Stratum_Keyword_Thesaurus: none

Stratum_Keyword: None

Temporal:

Temporal_Keyword_Thesaurus: none

Temporal_Keyword: Spring

Temporal_Keyword: 2012

Access_Constraints: None

Use_Constraints:

The data depicts the elevations at time of survey and are accurate only for that time. Exercise professional judgment in using this data.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Digital Aerial Solutions. LLC.

Contact_Address:

Address_Type: mailing and physical address

Address: 8409 Laurel Fair Circle Ste: 100

City: Tampa

State_or_Province: Florida

Postal_Code: 33610

Country: USA

Contact_Voice_Telephone: (813) 628-0788

Contact_Electronic_Mail_Address: mjordan@digitalaerial.com

Hours_of_Service: 8:00 - 5:00

Data_Set_Credit: Digital Aerial Solutions. LLC.

Security_Information:

Security_Classification_System: Unclassified

Security_Classification: Unclassified

Security_Handling_Description: Information Unclassified

Native_Data_Set_Environment:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

There is not a systematic method of testing when testing horizontal accuracy in LiDAR. The horizontal accuracy is checked by collecting building corners during the survey. Lines are then digitized representing the building outline and the differences are measure from each individual survey point to the corner of the building outline. Stats are calculated to ensure horizontal tolerances are met. These measurements resulted in an RMSE of .42 meters and equals a .73 meter horizontal accuracy at the 95 % confidence level.

Logical_Consistency_Report:

The GPS survey was tied into the Trimble VRS Now Network located in Florida. The Trimble VRS Now network is a network of continuously operating GPS reference stations that provides Real Time Kinematic (RTK) capabilities within a Real Time Network (RTN). This allows corrections to be applied to the points as they are being collected, eliminating the need for an adjustment. Several existing control monuments listed in the NSRS database were used as checks within the Trimble VRS Now Network. This confirmed network accuracies were being met during the field survey as well as providing a redundancy check on the Trimble VRSnetwork. The Specified local network accuracy of 5cm at the 95% confidence level was met or exceeded. Data analysis was accomplished by comparing ground truth checkpoints with LIDAR points from the edited data set, which were within 3.3 feet horizontally from the ground truth points. Based on the number of returns and the density of points in this project, it was not necessary to compare to anything further away than 3.3 feet horizontally from the ground truth points. Note that the edited LIDAR points are simply a subset of the raw LIDAR points. The points that fell above the ground surface on vegetation canopies, buildings, or other obstructions were removed from the data set. Comparisons were also made between the survey points and the LIDAR derived terrain surface. These comparisons provide an additional verification of the LIDAR data against the survey data.

Completeness_Report:

Ground Truth data was collected of the three major land cover classes dispersed within the area of interest. 20 points were collected in each of the three predominate vegetation classes low vegetation, medium vegetation, and high vegetation, points collected in high vegetation were collected with a Total Station. Pair of points was surveyed using the Trimble VRS network once completed the total station is used to collect the high vegetation ground class. A Topcon 7000 total station was used to collect all the shots collected in the high vegetation class, due to the limited GPS signal when working in and around tree canopy.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

There is not a systematic method of testing when testing horizontal accuracy in LiDAR. However this is tested during calibration of the sensor and is rechecked during the comparing of parallel and perpendicular flight lines. Additionally the horizontal accuracy is checked by collecting building corners during the survey. Lines are then digitized representing the building outline and the differences are measure from each individual survey point to the corner of the building outline. Stats are calculated to ensure horizontal tolerances are met. These measurements resulted in an RMSE of .42 meters and equals a .73 meter horizontal accuracy at the 95 % confidence level. Accuracy defined by NSSDA at the 95 % confidence level would be multiplier by 1.7308 times the RMSE.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

Data over well-defined surfaces has been tested to meet an 0.60 ft Fundamental Vertical Accuracy (FVA) at 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines. Outliers or systematic errors identified through spatial analysis and analyzed mean were eliminated from the set of observations. These errors could not be corrected through standardized adjustment or caused by a misinterpretations of terrain surface. These eliminated observations are as followed LC2-206(Urban), LC3-205 (TallWeeds), LC3207(TallWeeds), LC3-210(TallWeeds), LC4-206(Brushland), LC4-207(Brushland), LC5-206(Forested), LC5-207(Forested)..

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: RMSEZ of TIN = 0.20 ft FVA of TIN = 0.41 ft

Vertical_Positional_Accuracy_Explanation:

REMSE Z of LiDAR Point Cloud Tin tested at 0.20ft. fundamental vertical accuracy (FVA) of LiDAR Point cloud TIN tested at 0.41 ft . Tested against the TIN.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: RMSEz of DEM = 0.22 ft FVA of DEM = 0.44 ft

Vertical_Positional_Accuracy_Explanation:

RMSEz of DEM tested 0.22 ft FVA of the DEM tested 0.44 ft at 95% confidence level. Tested against the DEM.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: SVA = 0.43 ft

Vertical_Positional_Accuracy_Explanation:

Tested 0.43 ft. supplemental vertical accuracy (SVA) at the 95th percentile in Urban catagories. Tested against the DEM.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: SVA = 0.72 ft

Vertical_Positional_Accuracy_Explanation:

Tested 0.72. ft supplemental vertical accuracy (SVA) at the 95th percentile in Tall weeds catagories. Tested against the DEM.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: SVA = 0.59 ft

Vertical_Positional_Accuracy_Explanation:

Tested 0.59 ft supplemental vertical accuracy (SVA) at the 95th percentile in Brush Land catagories. Tested against the DEM.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: SVA = 0.86 ft

Vertical_Positional_Accuracy_Explanation:

Tested 0.86 ft.supplemental vertical accuracy (SVA) at the 95th percentile in Forested catagories. Tested against the DEM.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: CVA 0.63 ft

Vertical_Positional_Accuracy_Explanation:

Tested 0.63 ft consolidated vertical accuracy (CVA) at the 95th percentile in all categories of data. Tested against the DEM.

Lineage:

Process_Step:

Process_Description:

The ABGPS, inertial measurement unit (IMU), and raw scans are collected during the LiDAR aerial survey. The ABGPS monitors the xyz position of the sensor and the IMU monitors the orientation. During the aerial survey, laser pulses reflected from features on the ground surface are detected by the receiver optics and collected by the data logger. GPS locations are based on data collected by receivers on the aircraft and base stations on the ground. The ground base stations are placed no more than 40 km radius from the flight survey area.

Source_Used_Citation_Abbreviation: Leica ALS 60 serial number 137

Source_Used_Citation_Abbreviation: Airborne Global Positioning System

Source_Used_Citation_Abbreviation: Inertial Measuring Unit

Source_Used_Citation_Abbreviation: Global Positioning System

Process_Date: 20120416

Source_Produced_Citation_Abbreviation: LiDAR Scan Files

Source_Produced_Citation_Abbreviation: LiDAR Scans, GPS data

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Digital Aerial Solutions

Contact_Address:

Address_Type: mailing and physical address

Address: 8409 Laurel Fair Cir

City: Tampa

State_or_Province: FL

Postal_Code: 33610

Country: USA

Contact_Voice_Telephone: 813 628 0788

Contact_Electronic_Mail_Address: jhelton@digitalaerial.com

Hours_of_Service: 8-5 CST

Process_Step:

Process_Description:

The ABGPS, IMU, and raw scans are integrated using proprietary software developed by Leica and delivered with the Leica System. The resultant file is in a LAS binary file format. The LAS version 1.2 file format can be easily transferred from one file format to another. It is a binary file format that maintains information specific to the LiDAR data (return number, intensity value, xyz, etc.). The resultant points are produced in the NAD83/2007 HARN State Plane Florida North Coordinate System, with units in U.S. Survey Feet and referenced to the NAVD88 datum. The LiDAR mass points were processed in American Society for Photogrammetry and Remote Sensing LAS 1.2 format. The header file for each dataset is complete as defined by the LAS 1.2 specification. The datasets were divided into a 1500 m by 1500 m tiling scheme, based on the US National Grid. The tiles are contiguous, do not overlap, and are suitable for seamless topographic data mosaics that include no "no data" areas. The names of the tiles include numeric column and row designations and all files utilize the LAS file extension

Source_Used_Citation_Abbreviation: Airborne Global Positioning System data

Source_Used_Citation_Abbreviation: Inertial Measurement Unit

Source_Used_Citation_Abbreviation: LiDAR scans

Process_Date: 20120629

Source_Produced_Citation_Abbreviation: LiDAR Point Cloud data sets LAS 1.2 file format

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Digital Aerial Solutions

Contact_Address:

Address_Type: mailing and physical address

Address: 8409 Laurel Fair Cir

City: Tampa

State_or_Province: FL

Postal_Code: 33610

Country: USA

Contact_Voice_Telephone: (813 628 0788

Contact_Electronic_Mail_Address: jhelton@digitalaerial.com

Hours_of_Service: 8-5 CST

Process_Step:

Process_Description:

The unedited data are classified to facilitate the application of the appropriate feature extraction filters. A combination of proprietary filters are applied as appropriate for the production of bare earth digital elevation models (DEMs). Interactive editing methods are applied to those areas where it is inappropriate or impossible to use the feature extraction filters, based upon the design criteria and/or limitations of the relevant filters. These same feature extraction filters are used to produce elevation height surfaces.

Source_Used_Citation_Abbreviation: LAS 1.2 Format

Process_Date: 20120622

Source_Produced_Citation_Abbreviation: Filtered data LiDAR datasets

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Digital Aerial Solutions

Contact_Address:

Address_Type: mailing and physical address

Address: 8409 Laurel Fair Cir

City: Tampa

State_or_Province: FL

Postal_Code: 33610

Country: USA

Contact_Voice_Telephone: 813 628 0788

Contact_Electronic_Mail_Address: jhelton@digitalaerial.com

Hours_of_Service: 8-5 CST

Process_Step:

Process_Description:

Filtered and edited data are subjected to rigorous QA/QC, A series of quantitative and visual procedures are employed to validate the accuracy and consistency of the filtered and edited data. Ground control is established by DAS and GPS-derived ground control points (GCPs) in various areas of dominant and prescribed land cover. These points are coded according to land cover, surface material, and ground control suitability. A suitable number of points are selected for calculation of a statistically significant accuracy assessment, as per the requirements of the National Standard for Spatial Data Accuracy. A spatial proximity analysis is used to select edited LiDAR data points within a specified distance of the relevant GCPs. A search radius decision rule is applied with consideration of terrain complexity, cumulative error, and adequate sample size. Accuracy validation and evaluation is accomplished using proprietary software to apply relevant statistical routines for calculation of Root Mean Square Error (RMSE) and the National Standard for Spatial Data Accuracy (NSSDA), according to Federal Geographic Data Committee (FGDC) specifications.

Source_Used_Citation_Abbreviation: Filtered LiDAR 1.2 data

Process_Date: 20120629

Source_Produced_Citation_Abbreviation: Quality verified bare earth data set

Source_Produced_Citation_Abbreviation: 3-D hydrologic breaklines

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Digital Aerial Solutions

Contact_Address:

Address_Type: mailing and physical address

Address: 813 628 0788

City: Tampa

State_or_Province: FL

Postal_Code: 33610

Country: USA

Contact_Voice_Telephone: 813 628 0788

Contact_Electronic_Mail_Address: jhelton@digitalaerial.com

Hours_of_Service: 8-5 CST

Process_Step:

Process_Description:

The Bare Earth DEM was extracted from the raw LIDAR products and attributed with the bare earth elevation for each cell of the DEM. Bare Earth DEMs do not include buildings, vegetation, bridges or overpass structures in the bare earth model. Where abutments were clearly delineated, this transition occurred at the junction of the bridge and abutment. Where this junction was not clear, the extractor used their best estimate to delineate the separation of ground from elevated bridge surface. In the case of bridges over water bodies, if the abutment was not visible, the junction was biased to the prevailing stream bank so as not to impede the flow of water in a hydrographic model. Bare earth surface includes the top of water bodies not underwater terrain, if visible.

Source_Used_Citation_Abbreviation: Bare Earth LiDAR Returns

Process_Date: 20120629

Source_Produced_Citation_Abbreviation: 1 meter Bare-Earth DEM

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Digital Aerial Solutions

Contact_Address:

Address_Type: mailing and physical address

Address: 8409 Laurel Fair Cir

City: Tampa

State_or_Province: FL

Postal_Code: 33610

Country: USA

Contact_Voice_Telephone: 813 628 0788

Contact_Electronic_Mail_Address: jhelton@digitalaerial.com

Hours_of_Service: 8-5 CST

Cloud_Cover: 0

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Pixel

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Florida State Plane East

Lambert_Conformal_Conic:

Standard_Parallel: 29.583333

Standard_Parallel: 30.750000

Longitude_of_Central_Meridian: -84.500000

Latitude_of_Projection_Origin: 29.000000

False_Easting: 1968500.000000

False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: row and column

Coordinate_Representation:

Abscissa_Resolution: 0.000328

Ordinate_Resolution: 0.000328

Planar_Distance_Units: US Survey Feet

Geodetic_Model:

Horizontal_Datum_Name: North American Datum 1983/2007 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_Resolution: 0.001000

Altitude_Distance_Units: US Survey Feet

Altitude_Encoding_Method:

Explicit elevation coordinate included with horizontal coordinates

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: 32-bit ESRI float grid format bare earth tiles

Entity_Type_Definition: 32-bit Floating Point ESRI GRID format

Entity_Type_Definition_Source: ESRI

Overview_Description:

Entity_and_Attribute_Overview:

The Light Detection and Ranging (LiDAR) dataset is a survey of the FY12 St Johns River Water Management LiDAR Survey project area in north-central Florida and encompasses 800 square miles. The LiDAR point cloud was flown at a nominal post spacing of 1.0 meters for unobscured areas. The LiDAR data and derivative products produced are in compliance with the U.S. Geological Survey National Geospatial Program Guidelines and Base Specifications, Version 13-ILMF 2010. The flight lines were acquired by Digital Aerial Solutions, LLC. between April 02, 2012 and April 11, 2012. Derivative products from the aerial acquisition include: Raw point cloud data in LAS v1.2, classified point cloud data in LAS v1.2, bare earth surface tiles (raster DEM ESRI float GRID format), bare earth surface DEMs mosaic (raster DEM MrSID format), control points, project report, and FGDC compliant XML metadata.

Entity_and_Attribute_Detail_Citation:

The Light Detection and Ranging (LiDAR) dataset is a survey of the FY12 St Johns River Water Management LiDAR Survey project area in north-central Florida and encompasses 800 square miles. The LiDAR point cloud was flown at a nominal post spacing of 1.0 meters for unobscured areas. The LiDAR data and derivative products produced are in compliance with the U.S. Geological Survey National Geospatial Program Guidelines and Base Specifications, Version 13-ILMF 2010. The flight lines were acquired by Digital Aerial Solutions, LLC. between April 02, 2012 and April 11, 2012. Derivative products from the aerial acquisition include: Raw point cloud data in LAS v1.2, classified point cloud data in LAS v1.2, bare earth surface tiles (raster DEM ESRI float GRID format), bare earth surface DEMs mosaic (raster DEM MrSID format), control points, project report, and FGDC compliant XML metadata.

Metadata_Reference_Information:

Metadata_Date: 20121113

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Joshua Helton

Contact_Organization: Digital Aerial Solutions. LLC.

Contact_Position: LiDAR Manager

Contact_Address:

Address_Type: mailing and physical address

Address: 8409 Laurel Fair Circle Ste:100

City: Tampa

State_or_Province: Florida

Postal_Code: 33610

Country: USA

Contact_Voice_Telephone: (813) 628-0788

Contact_Facsimile_Telephone: (813) 628-0777

Contact_Electronic_Mail_Address: jhelton@digitalaerial.com

Hours_of_Service: 8:00 - 5:00 EST

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Access_Constraints: To be determined by client

Metadata_Use_Constraints: none

Metadata_Security_Information:

Metadata_Security_Classification_System: Geography

Metadata_Security_Classification: Unclassified

Metadata_Security_Handling_Description: Information Unclassified