2015-2016 USGS/FEMA Lidar: Connecticut River Watershed, NH

Geographic Extent: Connecticut River Watershed (4,437 sq mi), Winnipesaukee River Watershed (796 sq mi), and portions of the White Mountain National Forest (WMNF) in New Hampshire (181 sq mi), covering approximately 5,233 total square miles.

Dataset Description: The Connecticut River Watershed 2015 project called for the planning, acquisition, processing and derivative products of LIDAR data to be collected at an aggregate nominal pulse spacing (NPS) of 0.7 meters the Connecticut and Winnipesaukee River Watershed areas of interest, and 0.58 meters NPS for the White Mountain National Forest project area. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2 as well as the National Enhanced Elevation Assessment (NEEA) for QL2/QL2+ data for the WMNF area. The data was developed based on a horizontal projection/datum of NAD83 (2011) State Plane New Hampshire, US survey feet and vertical datum of NAVD88 (Geoid 12B), US survey feet. Lidar data for all three areas of interest was delivered in RAW LAS 1.4 flightline swath format, and processed to create Classified LAS 1.4 Files formatted to 6,464 individual 5,000-foot x 5,000-foot tiles.

After approval of the initial dataset was received from the USGS, the additional deliverables was produced for the White Mountain National Forest project area. This dataset includes tiled classified LAS data (first and last return) in LAS 1.4 and comma-delimited ASCII formats and 2.5-foot bare-earth raster DEMs in Esri grid format. Tiles names follow the naming schema implemented in previous WMNF task orders.

Data were subsequently reprocessed to Entwine Point Tile (EPT) format in web mercator projection with vertical meters. The EPT form of the data is used by the NOAA Digital Coast Data Access Viewer, which this metadata record is supporting. Additional processing steps may have been done by the Data Access Viewer and will be recorded in the lineage section.

Ground Conditions: LiDAR collection began in Fall 2015, 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, Quantum Spatial established 155 calibration control points in order to calibrate the LIDAR to known ground locations established throughout the project area. The accuracy of the data was checked with 135 NVA points and 117 VVA points (252 total QC checkpoints).

Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create breaklines, raster DEMs, and intensity images.

The purpose of these lidar data was to produce high accuracy 3D hydro-flattened digital elevation models (DEM) and intensity images with a 2.5-foot cell size.

These raw lidar point cloud data were used to create classified lidar LAS files, 3D breaklines, hydro-flattened DEMs, and intensity images as necessary.

USGS Contract: G10PC00026 Task Order Number: G15PD00886

CONTRACTOR: Quantum Spatial

Lidar data calibrated by Quantum Spatial, Inc. with data acquired by QSI, Woolpert, Inc., and PAR.

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

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.69",

"ldrdens" : "2.12",

"ldranps" : "0.69",

"ldradens" : "2.12",

"ldrfltht" : "2075",

"ldrfltsp" : "160",

"ldrscana" : "40.0",

"ldrscanr" : "40.7",

"ldrpulsr" : "264.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.47",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1510.48",

"ldrswato" : "13.11",

"ldrgeoid" : "g2012bu0.bin"

},

"ldrinfo_Concord" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.69",

"ldrdens" : "2.12",

"ldranps" : "0.69",

"ldradens" : "2.12",

"ldrfltht" : "2075",

"ldrfltsp" : "160",

"ldrscana" : "40.0",

"ldrscanr" : "40.7",

"ldrpulsr" : "264.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.47",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1510.48",

"ldrswato" : "12.70",

"ldrgeoid" : "g2012bu0.bin"

},

"ldrinfo_Keene" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.69",

"ldrdens" : "2.12",

"ldranps" : "0.69",

"ldradens" : "2.12",

"ldrfltht" : "2075",

"ldrfltsp" : "160",

"ldrscana" : "40.0",

"ldrscanr" : "40.7",

"ldrpulsr" : "264.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.47",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1510.48",

"ldrswato" : "13.23",

"ldrgeoid" : "g2012bu0.bin"

},

"ldrinfo_Lebanon" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.69",

"ldrdens" : "2.12",

"ldranps" : "0.69",

"ldradens" : "2.12",

"ldrfltht" : "2075",

"ldrfltsp" : "160",

"ldrscana" : "40.0",

"ldrscanr" : "40.7",

"ldrpulsr" : "264.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.47",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1510.48",

"ldrswato" : "13.25",

"ldrgeoid" : "g2012bu0.bin"

},

"ldrinfo_Pittsburg" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.69",

"ldrdens" : "2.12",

"ldranps" : "0.69",

"ldradens" : "2.12",

"ldrfltht" : "2075",

"ldrfltsp" : "160",

"ldrscana" : "40.0",

"ldrscanr" : "40.7",

"ldrpulsr" : "264.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.47",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1510.48",

"ldrswato" : "13.54",

"ldrgeoid" : "g2012bu0.bin"

},

"ldrinfo_StJohnsburyNorth" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.69",

"ldrdens" : "2.12",

"ldranps" : "0.69",

"ldradens" : "2.12",

"ldrfltht" : "2075",

"ldrfltsp" : "160",

"ldrscana" : "40.0",

"ldrscanr" : "40.7",

"ldrpulsr" : "264.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.47",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1510.48",

"ldrswato" : "12.68",

"ldrgeoid" : "g2012bu0.bin"

},

"ldrinfo_StJohnsburySouth" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.69",

"ldrdens" : "2.12",

"ldranps" : "0.69",

"ldradens" : "2.12",

"ldrfltht" : "2075",

"ldrfltsp" : "160",

"ldrscana" : "40.0",

"ldrscanr" : "40.7",

"ldrpulsr" : "264.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.47",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1510.48",

"ldrswato" : "12.17",

"ldrgeoid" : "g2012bu0.bin"

},

"ldrinfo_Winnepesaukee" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.69",

"ldrdens" : "2.12",

"ldranps" : "0.69",

"ldradens" : "2.12",

"ldrfltht" : "2075",

"ldrfltsp" : "160",

"ldrscana" : "40.0",

"ldrscanr" : "40.7",

"ldrpulsr" : "264.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.47",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1510.48",

"ldrswato" : "12.82",

"ldrgeoid" : "g2012bu0.bin"

},

"ldrinfo_WMNF" : {

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

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.56",

"ldrdens" : "3.21",

"ldranps" : "0.56",

"ldradens" : "3.21",

"ldrfltht" : "160",

"ldrfltsp" : "160",

"ldrscana" : "28.0",

"ldrscanr" : "49.6",

"ldrpulsr" : "273.0",

"ldrpulsd" : "4",

"ldrpulsw" : "0.047",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1034.71",

"ldrswato" : "19.98",

"ldrgeoid" : "g2012bu0.bin"

},

"ldraccur" : {

"ldrchacc" : "0.196",

"rawnva" : "0.093",

"rawnvan" : "133",

"clsnva" : "0.092",

"clsnvan" : "134",

"clsvva" : "0.284",

"clsvvan" : "116"

},

"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" : "16",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare-earth ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low noise"

},

"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 NOAA, the Office for Coastal Management or its partners

Data is available online for bulk or 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 2014.1.21.4; ESRI ArcGIS 10.3; Global Mapper 16; Leica Cloud Pro 1.2; Windows 7 Operating System

\\PSIHQ_NX3200\Projects\Projects\26818_CT_River_Watershed_Winnipesaukee 597 GB and \\matrix\matrix\LIDAR\26818_CT_River 11.9 TB

Quantitative values: 0.093 m, 0.092 m, and 0.284 m.

Tests that produced these values:

The raw NVA was tested using 133 independent survey points located in open terrain. The surveyed checkpoints were distributed throughout the project area and surveyed using GNSS procedures and methodologies that provide reliable and consistent results to meet the project's accuracy requirements. Please see the "Survey Accuracy Requirements" and "Field Methodology" sections in the Survey Report for more information. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the unclassified lidar surface were then compared to the elevation values of the surveyed control. The RMSEz was computed to be 0.047 meters and AccuracyZ to be 0.093 meters. This meets the required AccuracyZ value of 0.196 meters raw 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.

The NVA was tested using 134 independent survey points located in open terrain. The surveyed checkpoints were distributed throughout the project area and surveyed using GNSS procedures and methodologies that provide reliable and consistent results to meet the project's accuracy requirements. Please see the "Survey Accuracy Requirements" and "Field Methodology" sections in the Survey Report for more information. Elevations from the DEM surface were measured for the x,y location of each check point. Elevations interpolated from the DEM surface were then compared to the elevation values of the surveyed control. The RMSEz was computed to be 0.047 meters and AccuracyZ to be 0.092 meters. This meets the required AccuracyZ value of 0.196 meters 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.

The VVA was tested using 116 independent survey points located in vegetated terrain. The surveyed checkpoints were distributed throughout the project area and surveyed using GNSS procedures and methodologies that provide reliable and consistent results to meet the project's accuracy requirements. Please see the "Survey Accuracy Requirements" and "Field Methodology" sections in the Survey Report for more information. Elevations from the DEM surface were measured for the x,y location of each check point. Elevations interpolated from the DEM surface were then compared to the elevation values of the surveyed control. The VVA was computed to be 0.284 meters. This meets the required value of 0.294 meters VVA at 95th percentile level using the 95th percentile of the absolute value of all vertical errors in all combined vegetation classes 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 cloud storage.