2015 NYS ITS Lidar: Madison and Ostego Counties, NY

This data set consists of LiDAR Point Cloud data that covers approximately 1,844 square miles in Madison and Ostego Counties in New York. Each classified LAS tile contains LiDAR point information, which has been calibrated, controlled, and classified.

Ground Conditions: water at normal levels; no unusual inundation; no snow; leaf off

How the Withheld Points are Identified: There were no Withheld (ignore) points identified in the files using the standard LAS Withheld bit.

Class Code:1

Class Item: Undetermined/Unclassified

Class Code:2

Class Item: Ground

Class Code:7

Class Item:Low Point (Noise)

Class Code:9

Class Item:Water

Class Code:10

Class Item:Ignore Ground

Class Code:17

Class Item:Bridge Deck

Class Code:18

Class Item:High Noise

Points with extreme elevations (negative values, or positive values well above the expected maximum) are present in this dataset. These points are classified as low or high noise in classified point cloud tiles.

This metadata record supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

The State of New York has contracted Axis GeoSpatial, LLC to obtain professional services related to the collection of Light Detection and Ranging (LiDAR) data between December 2015 and March 2016. The purpose of these lidar data was to produce high accuracy 3D Digital Elevation Model (DEM) with a 1.0 meter cell size. The raw lidar point cloud data were used to create classified lidar LAS files, and Bare Earth DEMs as necessary.

All Lidar data was acquired, calibrated, and used in the creation of Lidar derived products by Axis GeoSpatial, LLC.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

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

"ldrsens" : "Trimble Harrier 68i; Optech Gemini",

"ldrmaxnr" : "7; 7",

"ldrnps" : ".69; .68",

"ldrdens" : "2.07; 2.18",

"ldranps" : ".69; .68",

"ldradens" : "2.07; 2.18",

"ldrfltht" : "718; 700",

"ldrfltsp" : "120-125; 150-160",

"ldrscana" : "60; 15.6",

"ldrscanr" : "90.7; 60.8",

"ldrpulsr" : "200; 70",

"ldrpulsd" : "4, 4",

"ldrpulsw" : ".44; .67",

"ldrwavel" : "1047; 1047",

"ldrmpia" : "1; 1",

"ldrbmdiv" : ".5; .25",

"ldrswatw" : "1020.76; 390.36",

"ldrswato" : "30; 30",

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

},

"ldraccur" : {

"ldrchacc" : "0.196",

"rawnva" : "0.058",

"rawnvan" : "373",

"clsnva" : "0.046",

"clsnvan" : "373",

"clsvva" : "0.073",

"clsvvan" : "381"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withhled (ignore) points were identified in the 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" : "Undetermined/Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Ignored Ground (near a breakline)"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Deck"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

}

}}

Overall Project Metadata

The data represented is the result of data collection and processing per contract specifications and indicates the general existing conditions at the time of data collection. As such, it is only valid for its intended use, content, time, and accuracy specifications. The user is responsible for the results of any application of the data for other than its intended purpose.

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 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.

Inpho-5.5.1; Terrascan 2015 015.006; Terramatch 2015 015.009; Terramodeler 2015 015.002; Windows 7 Operating System

Horizontal error in lidar derived elevation data is largely a function of positional error as derived from the Global Navigation Satellite System (GNSS), attitude (angular orientation) error (as derived from the INS) and flying altitude; and can be estimated based on these parameters. As described in Section 7.5 of the ASPRS Positional Accuracy Standards for Digital Geospatial Data the horizontal errors in lidar data are largely a function of GNSS positional error, INS angular error, and flying altitude. Therefore lidar data collected with GNSS error of 0.05m and the IMU error of 0.005 degrees at an altitude of 549 m; the expected radial horizontal positional error will be RMSEr = 9.92 cm

Vertical Accuracy of the point cloud and bare-earth lidar data was assessed and reported in accordance with the ASPRS Positional Accuracy Standards for Digital Geospatial Data. Seven hundred sixty-one (761) surveyed points were measured for the purpose of assessing the accuracy of the New York AOI data, but 4 of the NVA points were on bridges and were eliminated. This left seven hundred fifty-seven (757) points (376 NVA, 381 VVA) for vertical accuracy assessment.

This data set was tested on 376 NVA checkpoints to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10.0 (cm) RMSEz Vertical Accuracy Class. Actual NVA accuracy of the bare-earth was found to be RMSEz = 0.047 m, equating to +/- 0.092 m at 95% confidence level.

This data set was tested on 381 VVA checkpoints to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 10.0 (cm) RMSEz Vertical Accuracy Class. Actual VVA accuracy was found to be RMSEz = 0.073 m, equating to +/- 0.143 m at 95% confidence level.

The raw LAS data files included 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 Fundamental Vertical Accuracy specifications.Void areas (i.e., areas outside the project boundary but within the tiling scheme) are coded using a unique NODATA value. This value is identified in the appropriate location within the file header.

All LiDAR data and LiDAR Derived data covers the entire 1,844 square mile Area of Interest with in New York. All LiDAR Point Cloud tiles show no edge artifacts or mismatches from tile to tile. Void areas (i.e. areas outside the project boundary but within the tiling scheme) are coded using a unique NODATA value. This value is identified in the appropriate location within the file header. Data cover the entire area specified for this project.

Data is backed up to tape and to cloud storage.

The NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tile (EPT) file hosted on Amazon Web Services (AWS) into the Digital Coast Data Access Viewer (DAV). The DAV accesses the point cloud as it resides on AWS under the usgs-lidar-public-container.