2015 DVRPC Lidar: Delaware Valley - 5A, PA

Geographic Extent: This data set is part of a larger collection of the Delaware Valley, covering approximately 3260 square miles over the Philadelphia Metro area, comprised of of 8 contiguous counties located in the states of Pennsylvania and New Jersey. This data set was a re-flight, flown on November 25, 2015, after the initial collection of the larger data set in April 2015. This area was re-flown due to weather and leaf pop. This data set covers an area in Delaware, Montgomery, and Philadelphia Counties, PA.

Dataset Description: Delaware Valley 2015 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 1.2. The data was developed based on a horizontal projection/datum of UTM Zone 18, NAD83 (2011), meters and vertical datum of NAVD1988 (GEOID12A), meters. LiDAR data was delivered in RAW flight line swath format, processed to create Classified LAS 1.4 Files formatted to 25 individual 1500 meter X 1500 meter tiles for the pilot (3752 individual 1500 meter X 1500 meter tiles for the entire project area), Bare Earth DEMs tiled to the same 1500 meter X 1500 meter tile schema, and Breaklines in Esri shapefile format.

Ground Conditions: LiDAR was collected in spring of 2015, while no snow was on the ground and rivers were at or below normal levels. The re-flight area was collected in November 2015. In order to post process the LiDAR data to meet task order specifications, Quantum Spatial established a total of 155 Land Cover control points that were used to calibrate the LIDAR to known ground locations established throughout the Delaware Valley project area (75 calibration control points).

The NOAA Office for Coastal Management (OCM) downloaded this data set from this USGS site:

ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_LPC_DE_DelawareValleyHD_5A_2015_LAS_2017

These files were processed to the Data Access Viewer (DAV) and https. The total number of laz files downloaded and processed was 167.

The breaklines were also downloaded and are available for download at the link provided in the URL section of this metadata record. Please note that this product has not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.

Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Breaklines and Raster. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 1-meter cell size. These raw lidar point cloud data were used to create classified lidar LAS files, 3D breaklines, and hydro-flattened DEMs as necessary.

USGS Contract: G10PC00026 Task Order Number: G15PD00316

CONTRACTOR: Quantum Spatial

Lidar data were acquired and calibrated by Quantum Spatial.

All follow-on processing was completed by the prime contractor.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Lidar Specification v1.2",

"ldrsens" : "ALS80-HP-8239",

"ldrmaxnr" : "4",

"ldrnps" : "0.34",

"ldrdens" : "8.05",

"ldranps" : "0.34",

"ldradens" : "8.05",

"ldrfltht" : "1541",

"ldrfltsp" : "150",

"ldrscana" : "18.0",

"ldrscanr" : "40.5",

"ldrpulsr" : "695.80",

"ldrpulsd" : "4",

"ldrpulsw" : "0.40",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1023.50",

"ldrswato" : "19.68",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldrinfo31E" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS80-HP-8239",

"ldrmaxnr" : "4",

"ldrnps" : "0.34",

"ldrdens" : "8.00",

"ldranps" : "0.34",

"ldradens" : "8.00",

"ldrfltht" : "1580",

"ldrfltsp" : "150",

"ldrscana" : "18.0",

"ldrscanr" : "40.5",

"ldrpulsr" : "693.60",

"ldrpulsd" : "4",

"ldrpulsw" : "0.40",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1026.75",

"ldrswato" : "19.43",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldrinfoCKZ" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS80-HP-8239",

"ldrmaxnr" : "4",

"ldrnps" : "0.34",

"ldrdens" : "7.65",

"ldranps" : "0.34",

"ldradens" : "7.65",

"ldrfltht" : "1599",

"ldrfltsp" : "150",

"ldrscana" : "14.5",

"ldrscanr" : "26.0",

"ldrpulsr" : "532.40",

"ldrpulsd" : "4",

"ldrpulsw" : "0.40",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "814.65",

"ldrswato" : "24.91",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldrinfoLOM" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS80-HP-8239",

"ldrmaxnr" : "4",

"ldrnps" : "0.34",

"ldrdens" : "7.85",

"ldranps" : "0.34",

"ldradens" : "7.85",

"ldrfltht" : "1774",

"ldrfltsp" : "150",

"ldrscana" : "14.5",

"ldrscanr" : "51.0",

"ldrpulsr" : "623.20",

"ldrpulsd" : "4",

"ldrpulsw" : "0.46",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "931.02",

"ldrswato" : "23.10",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldrinfoOQN" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS80-HP-8239",

"ldrmaxnr" : "4",

"ldrnps" : "0.34",

"ldrdens" : "7.70",

"ldranps" : "0.34",

"ldradens" : "7.70",

"ldrfltht" : "1765",

"ldrfltsp" : "150",

"ldrscana" : "14.8",

"ldrscanr" : "51.0",

"ldrpulsr" : "622.40",

"ldrpulsd" : "4",

"ldrpulsw" : "0.46",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "947.80",

"ldrswato" : "22.76",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldrinfo_downtown" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS80-HP-8239",

"ldrmaxnr" : "4",

"ldrnps" : "0.34",

"ldrdens" : "7.79",

"ldranps" : "0.34",

"ldradens" : "7.79",

"ldrfltht" : "1555",

"ldrfltsp" : "150",

"ldrscana" : "14.0",

"ldrscanr" : "57.0",

"ldrpulsr" : "528.80",

"ldrpulsd" : "4",

"ldrpulsw" : "0.40",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "792.86",

"ldrswato" : "24.57",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldrinfoVAY" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS80-HP-8239",

"ldrmaxnr" : "4",

"ldrnps" : "0.34",

"ldrdens" : "8.00",

"ldranps" : "0.34",

"ldradens" : "8.00",

"ldrfltht" : "1546",

"ldrfltsp" : "150",

"ldrscana" : "18.0",

"ldrscanr" : "40.5",

"ldrpulsr" : "693.60",

"ldrpulsd" : "4",

"ldrpulsw" : "0.40",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1026.75",

"ldrswato" : "19.69",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldrinfoN87" : {

"ldrspec" : "USGS-NGP Base Specification v1.2",

"ldrsens" : "ALS80-HP-8239",

"ldrmaxnr" : "4",

"ldrnps" : "0.34",

"ldrdens" : "7.95",

"ldranps" : "0.34",

"ldradens" : "7.95",

"ldrfltht" : "1356",

"ldrfltsp" : "150",

"ldrscana" : "17.5",

"ldrscanr" : "47.5",

"ldrpulsr" : "591.00",

"ldrpulsd" : "4",

"ldrpulsw" : "0.35",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "876.53",

"ldrswato" : "21.65",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldraccur" : {

"ldrchacc" : "0.196",

"rawnva" : "0.082",

"rawnvan" : "87",

"clsnva" : "0.080",

"clsnvan" : "87",

"clsvva" : "0.265",

"clsvvan" : "68"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points were identified in these files using the standard LAS Withheld bit",

"lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit",

"lasintr" : "11-bit",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed but unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare earth ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low noise"

},

"lasclass" : {

"clascode" : "8",

"clasitem" : "Model Key Point"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored Ground"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High noise"

}

}}

Any conclusions drawn from the analysis of this information are not the responsibility of DVRPC, USGS, NOAA, the Office for Coastal Management or its partners.

Data is available online for bulk and custom downloads.

None

Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations.

MicroStation Version 8; TerraScan Version 15; TerraModeler Version 15; GeoCue Version 2014.1.21.1; ESRI ArcGIS 10.2; Global Mapper 16; Leica Cloud Pro 1.2; Windows 7 Operating System

\\psihq_nx3200\Projects\26236_DVRPC_LiDAR\ 24.1 GB and

\\Matrix\LIDAR\26236_DVRPC\ 5.09 TB

The specifications require that only Nonvegetated Vertical Accuracy (NVA) be computed for raw lidar point cloud swath files. The vertical accuracy was tested with 155 independent survey located in open terrain. These check points were not used in the calibration or post processing of the lidar point cloud data. The survey check points were distributed throughout the project. Specifications for this project require that the NVA be 19.6 cm or better AccuracyZ at 95 percent confidence level. 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. The RMSE was computed to be 0.041 meters. AccuracyZ has been tested to meet 19.6 cm NVA at 95 percent confidence level using (RMSEz * 1.9600) as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

These raw 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 Nonvegetated Vertical Accuracy specifications.

Data cover the entire area specified for this project.

Data is backed up to tape and to cloud storage.