Northwest NJ 2018 LiDAR Point Cloud (Compressed Files)


Identification Information:
Citation:
Citation Information:
Publication Date: 20190102
Title: Northwest NJ 2018 LiDAR Point Cloud (Compressed Files)
Geospatial Data Presentation Form: document
Description:
Abstract: Product: These lidar data are processed Classified LAS v1.4 files, formatted to 2,843 individual 5,000 ft x 5,000 ft tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: 6 counties, New Jersey, covering approximately 2,358 square miles. Dataset Description: Sussex, Passaic, Warren, Morris, Hunterdon, Somerset county, New Jersey 2018 Lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.3. The data was developed based on a horizontal projection/datum of NAD83 (2011), State Plane New Jersey, feet and vertical datum of NAVD88 (GEOID12B), feet. Lidar data was delivered as processed Classified LASv1.4 files, formatted to 2,843 individual 5,000 ft x 5,000 ft tiles, as tiled intensity imagery, and as tiled bare-earth DEMs; all tiled to the same 5,000 ft x 5,000 ft schema. Ground Conditions: Lidar was collected in early 2017 and 2018, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, The Sanborn Map Company, Inc. established a total of 30 ground control points that were used to calibrate the lidar to known ground locations established throughout the project area. An additional 140 independent accuracy check points, 79 in Open Terrain/Bare-Earth and Urban landcovers (79 NVA points), 61 in Grass, Brush and Trees categories (61 VVA points), were used to assess the vertical accuracy of the data. These check points were not used to calibrate or post process the data.
Purpose: To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare-earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 2 ft cell size. These raw lidar point cloud data were used to create classified lidar LAS files, intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.
Supplemental Information: USGS Contract: G16PC00051 CONTRACTOR: The Sanborn Map Company, Inc SUBCONTRACTOR: Keystone Aerial Surveys, Inc., Lidar data were acquired by Sanborn and Keystone. All follow-on processing was completed by the prime contractor.
Time Period of Content:
Time Period Information:
Range of Dates/Times:
Beginning Date: 20170415
Ending Date: 20190102
Currentness Reference: ground condition
Status:
Progress: Complete
Maintenance and Update Frequency: None planned
Spatial Domain:
Bounding Coordinates:
West Bounding Coordinate: -75.2064717766
East Bounding Coordinate: -74.0891615268
North Bounding Coordinate: 41.3594282505
South Bounding Coordinate: 40.3376257080
Keywords:
Theme:
Theme Keyword Thesaurus: None
Theme Keyword: Model
Theme Keyword: LAS Point Cloud
Theme Keyword: Remote Sensing
Theme Keyword: Elevation Data
Theme Keyword: Lidar
Theme:
Theme Keyword Thesaurus: ISO 19115 Topic Categories
Theme Keyword: elevation
Place:
Place Keyword Thesaurus: None
Place Keyword: New Jersey
Place Keyword: Sussex County
Place Keyword: Passaic County
Place Keyword: Warren County
Place Keyword: Morris County
Place Keyword: Hunderton County
Place Keyword: Somerset County
Access Constraints: No restrictions apply to these data.
Use Constraints: None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.
Point of Contact:
Contact Information:
Contact Organization Primary:
Contact Organization: Sanborn Map Company, Inc.
Contact Address:
Address Type: mailing and physical
Address: 1935 Jamboree Drive
Address: Suite 100
City: Colorado Springs
State or Province: CO
Postal Code: 80920
Country: US
Contact Voice Telephone: (866)726-2676
Data Quality Information:
Logical Consistency Report: Data covers the AOI specified for this project.
Completeness Report: These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.
Positional Accuracy:
Vertical Positional Accuracy:
Vertical Positional Accuracy Report: The project specifications require that only Non-Vegetated Vertical Accuracy (NVA) be computed for raw lidar point cloud swath files. The required accuracy (ACCz) is: 19.6 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 10 cm in the “bare earth” and "urban" land cover classes. The NVA was tested with 79 checkpoints located in open terrain/bare earth and urban (non-vegetated) areas. These check points were not used in the calibration or post processing of the lidar point cloud data. The check points were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the lidar surface were then compared to the elevation values of the surveyed control points. AccuracyZ has been tested to meet 19.6 cm or better Non-Vegetated Vertical Accuracy 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)/ASRPS Guidelines.
Quantitative Vertical Positional Accuracy Assessment:
Vertical Positional Accuracy Value: 0.508
Vertical Positional Accuracy Explanation: Tested 0.508 feet NVA at a 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA). The NVA of the raw lidar point cloud swath files was calculated against TINs derived from the final calibrated and controlled swath data using 79 independent check points located in Open Terrain/Bare Earth and Urban land cover classes.
Lineage:
Source Information:
Source Citation:
Citation Information:
Publication Date: 20190102
Title: Ground Control for New Jersey 6 County lidar project
Source Scale Denominator: 50
Type of Source Media: onLine
Source Time Period of Content:
Time Period Information:
Single Date/Time:
Calendar Date: 20180428
Source Currentness Reference: ground condition
Source Citation Abbreviation: Ground Control for New Jersey 6 County lidar project
Source Contribution: This data source was used (along with airborne GNSS/IMU data) to georeference the lidar point cloud data.
Process Step:
Process Description:
The following steps describe the Raw Data Processing and Calibration process: 1) Technicians processed the raw data to LAS format flight lines using the ABGNSS/IMU solution. 2) Technicians use TerraSolid TerraMatch to calculate initial calibration adjustment angles by mission and/or block. This is accomplished by identifying ground and above ground feature observations between flight-lines and calculating the offsets. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable. 3) Once the angle calculation was completed the adjusted settings were applied to all of the flight-lines of the mission and/or block and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze how well flight-line overlaps match and adjusted as necessary until the results met the project specifications. 4) The technicians checked and corrected the vertical misalignment of all flight-lines and also the matching between data and ground truth. The relative accuracy was less than or equal to 6 cm RMSEz within individual swaths and less than or equal to 8 cm RMSDz or within swath overlap (between adjacent swaths). 5) The technicians ran a final vertical accuracy check of the calibrated point cloud against the surveyed check points after the z correction to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required Accuracy) was met. Point classification was performed according to USGS Lidar Base Specification 1.2, and breaklines were collected for water features. Bare earth DEMs were exported from the classified point cloud using collected breaklines for hydroflattening.
Process Date: 20180101
Process Contact:
Contact Information:
Contact Organization Primary:
Contact Organization: Sanborn Map Company, Inc.
Contact Person: Shawn Benham
Contact Address:
Address Type: mailing and physical
Address: 1935 Jamboree Drive
Address: Suite 100
City: Colorado Springs
State or Province: CO
Postal Code: 80920
Country: US
Contact Voice Telephone: (719)502-1296
Contact Facsimile Telephone: (719)528-5090
Contact Electronic Mail Address: sbenham@sanborn.com
Hours: Monday - Friday 8 a.m. to 5 p.m. (Mountain Time)
Contact Instructions: If unable to reach the contact by telephone, please send an email. You should get a response within 24 hours.
Process Step:
Process Description:
LAS Point Classification: The point classification is performed as described below. The bare-earth surface is manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface is edited and QC'd, it is then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS Class 2) lidar data inside of the Lake Pond and River Pond hydro flattening breaklines were then classified to water (ASPRS Class 9) using LP360 functionality. A buffer of 2 feet was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 10). All Lake Pond Island and River Stream Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight-line data to approved classes by USGS. The overlap data was classified using standard LAS overlap bit. These classes were created through automated processes only and were not verified for classification accuracy. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper is used as a final check of the bare-earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for the Classified Point Cloud Data. LAStools, LP360 and TerraScan software was used to perform statistical analysis of the classes in the LAS files, on a per tile level to verify classification metrics and full LAS header information.
Process Date: 20190102
Spatial Data Organization Information:
Direct Spatial Reference Method: Vector
Distribution Information:
Distributor:
Contact Information:
Contact Person Primary:
Contact Person: NJ Office of Information Technology, Office of GIS (NJOGIS)
Contact Address:
Address Type: mailing
Address: PO Box 212
City: Trenton
State or Province: NJ
Postal Code: 08625-0212
Country: US
Contact Voice Telephone: use email
Contact Electronic Mail Address: njgin@oit.nj.gov
Distribution Liability: None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.
Standard Order Process:
Digital Form:
Digital Transfer Information:
Format Name: LAZ file
Format Version Number: 1.4
Digital Transfer Option:
Online Option:
Computer Contact Information:
Network Address:
Network Resource Name: https://njgin.nj.gov/njgin/edata/elevation/index.html
Fees: 0.00
Available Time Period:
Time Period Information:
Single Date/Time:
Calendar Date: 20191002
Metadata Reference Information:
Metadata Date: 20190926
Metadata Contact:
Contact Information:
Contact Organization Primary:
Contact Organization: Sanborn Map Company, Inc.
Contact Address:
Address Type: mailing and physical
Address: 1935 Jamboree Drive
Address: Suite 100
City: Colorado Springs
State or Province: CO
Postal Code: 80920
Country: US
Contact Voice Telephone: (866)726-2676
Metadata Standard Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata Standard Version: FGDC-STD-001-1998
Metadata Time Convention: local time