2011 - 2012 New York State Department of Environmental Conservation (NYSDEC) Lidar: Coastal New York (Long Island and along the Hudson River)

Light Detection and Ranging (LiDAR) data is remotely sensed high-resolution elevation data collected by an airborne collection

platform. This LiDAR dataset is a survey of areas of coastal New York, including Long Island, eastern Westchester, and the tidal

extents of the Hudson River. The project area consists of approximately 950 square miles. The project design of the LiDAR

data acquisition was developed to support a nominal post spacing of 1.0 meter or better (1.0 meter GSD). The LiDAR data vertical

accuracy is in compliance with the National Standard for Spatial Data Accuracy (NSSDA) RMSE estimation of elevation data in support

of 1 ft. contour mapping products. GMR Aerial Surveys Inc. d/b/a Photo Science, Inc. acquired 740 flight lines in 63 lifts

between November 2011 and April 2012, while no snow was on the ground, rivers were at or below normal levels, no strong onshore winds,

high waves, floods, or other anomalous weather conditions. Specified areas of the project were collected at a tide stage where

water levels are at least 1-foot below mean sea level (MSL). This collection was a joint effort by the NOAA Office for Coastal Management (OCM) and the New York State Department of Environmental Conservation. The data collection was performed with three

Cessna 206 single engine aircrafts, utilizing Optech Gemini sensors; collecting multiple return x, y, and z as well as intensity data.

The data were classified as Unclassified (1), Ground (2), Low Point (Noise) (7), Water (9), Breakline Edge (10), Withheld (11),

Tidal Water (14), Overlap Default (17), and Overlap Ground (18), Overlap Water (25), and Overlap Tidal Water (30). Upon receipt,

the NOAA Office for Coastal Management (OCM), for data storage and Digital Coast provisioning purposes, converted these classifications

to the following:

1 - Unclassified

2 - Ground

7 - Low Point (Noise)

9 - Water

NOAA tide gauges were used as the basis for flight planning the tidally coordinated areas. The Stevens Institute NY Harbor

Observation and Prediction System (NYHOPS) data were used to confirm accuracy of NOAA predicted tides in Hudson. Some areas were

collected using tidal restraints as listed below:

Tidal Wetlands and tributary mouths selected for tidal coordination at Mean Sea Level (MSL) minus 1 foot were:

Rondout Creek Outlet; Vanderburg Cove, Moodna Creek, Constitution Marsh, Iona Marsh, Annsville Creek, Croton River

Outlet, Marlboro Marsh, Manitou Marsh, Fishkill Creek Outlet, and Wappingers Creek Outlet. The Upper Hudson area from North

of Goose Island was also collected to the same specification.

Tidal Wetlands and tributary mouths selected for tidal coordination at Mean Sea Level (MSL) were Haverstraw at Minisceongo Creek

and Piermont Marsh.

On Long Island the following areas were collected at MSL:

1) the northern shore of Nassau and Suffolk counties from approximately Glen Cove on the western boundary to Nissequogue on

the eastern boundary

2) the Peconic Bay from Riverhead on the western boundary to the east end of Shelter Island and Accabonac Harbor on the eastern

boundary

3) western Great South Bay.

The remainder of the project area had no tidal restrictions for collection. LAS tiles indicate if they are tidally coordinated or not.

If tidal coordination only covers part of the tile the tile will be labeled tidally coordinated (i.e.MSL-1).

In order to post process the LiDAR data to meet task order specifications, Photo Science, Inc. established a total of 81 control

points that were used to calibrate the LiDAR to known ground locations established throughout the New York project area.

Trimble R8-3 GNSS receivers were used to complete the collection. Real Time Kinematic (RTK) survey methodology was

typically performed using the New York State Spatial Reference Network (NYSNet), a CORS/Real Time GPS Network.

Additionally, control values from various other projects completed by Photo Science in and around the project area, were used as

supplemental control points to assist in the calibration of the LiDAR dataset.

The dataset was developed based on a horizontal projection/datum of UTM NAD83 (NSRS2007), UTM Zone 18, meters and

vertical datum of NAVD1988 (GEOID09), meters. Upon receipt, for data storage and Digital Coast provisioning purposes, the NOAA

Office for Coastal Management converted the data to GRS80 Ellipsoid (GEOID09) heights, to geographic (NAD83, NSRS2007) coordinates,

and from las format to laz format.

LiDAR data were collected in RAW flightline swath format, processed to create Classified LAS 1.2 files formatted to 2093

individual 750m x 750m tiles, Hydro Flattening Breaklines in ESRI shapefile format, 1.0 meter gridded Tidal Water ERDAS IMAGINE (.img)

files formatted to 670 individual 3000m x 3000m tiles, and 1.0 meter gridded V-Datum ERDAS IMAGINE (.img) files formatted to the same

3000m x3000m tile schema. LiDAR data were originally delivered to NOAA/Dewberry for quality control validation under Delivery Lots 1 and 2.

The lineage (data quality), positional, content (completeness), attribution, logical consistency, and accuracies of all digital

elevation data produced conform to the specifications stipulated in NOAA Task Order EA133C11CQ0009 - T011.

The project was developed by the National Oceanic and Atmospheric Administration's (NOAA) Office for Coastal Management in

partnership with the New York State Department of Environmental Conservation (NYSDEC) to collect and deliver topographic elevation

point data derived from multiple return light detection and ranging (LiDAR) measurements for areas of coastal New York

including Long Island, eastern Westchester, and the tidal extents of the Hudson River. Data are intended for use in coastal management

decision making, including applications such as detailed mapping of areas at risk of sea level rise according to projections developed by

NYS and the remapping of Coastal Erosion Hazard Areas.

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.

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Lifts were flown out of specific airports at which base stations were set up and, sometimes, specific tide stations were used, creating another break in areas.

1B1 contained 46 flight lines and was flown on January 9, 2012 and January 11, 2012 with Optech SN247 in N2448G.

20N contained 39 flight lines and was flown on February 19-20, 2012 with Optech SN247 in N2448G.

ALB contained 31 flight lines and was flown on January 7, 2012 and January 9, 2012 with Optech SN247 in N2448G.

FRG-NOAA contained 144 flight lines flown on February 2-6, 2012; February 9, 2012; February 13-14, 2012 with Optech SN247 in N2448G.

GON contained 15 flight lines flown on November 26, 2011 with Optech SN240 in N9471R.

HTO contained 92 flight lines flown on January 15-16, 2012; January 18, 2012; and January 20, 2012 with Optech SN247 in N2448G.

HWV contained 110 flight lines flown on January 25, 2012; January 28, 2012; January 30-31, 2012 with Optech SN247 in N2448G.

POU contained 94 flight lines flown on December 12-14, 2012; and December 16, 2012 with Optech SN240 in N9471R.

SWF-NOAA contained 32 flight lines flown on December 18-19, 2011 with Optech SN240 in N9471R.

HPN contained 37 flight lines flown on April 6-7, 2012 with Optech SN246 in N7266Z.

1B1-TID-HUDSON contained 5 flight lines and was flown on February 20, 2012 with Optech SN247 in N2448G.

HPN-TID-CROTON contained 5 flight lines flown on February 19, 2012 with Optech SN247 in N2448G.

HPN-TID-HARVEST contained 6 flight lines flown on February 19, 2012 with Optech SN247 in N2448G.

HPN-TID-PIERMON contained 4 flight lines flown on February 18, 2012 with Optech SN247 in N2448G

SWF-TID-IONA-MA contained 9 flight lines flown February 17, 2012 with Optech SN247 in N2448G.

SWF-TID-MARL-WA contained 5 flight lines flown February 17, 2012 with Optech SN247 in N2448G.

SWF-TID-MOOD-FI contained 7 flight lines flown February 17, 2012 with Optech SN247 in N2448G.

A footprint of this data set may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1408/supplemental/2011_2012_NYSDEC_Lidar_Long_Island_and_Hudson_River.kmz

The Lidar Quality Assurance (QA) Report for the Hudson River area of this data set may be viewed at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1408/supplemental/Coastal_NY_Priority1_Dewberry_QA_Report.pdf

The Lidar Quality Assurance (QA) Report for the Long Island area of this data set may be viewed at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid18/1408/supplemental/Coastal_NY_Priority2_Dewberry_QA_Report.pdf

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

This data can be obtained on-line at the following URL:

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=1408

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1. The NYS DEC / NOAA asks to be credited in derived products.

2. Any documentation provided is an integral part of the data set. Failure to use the documentation in conjunction with the digital

data constitutes misuse of the data.

3. Although every effort has been made to ensure the accuracy of information, errors may be reflected in the data supplied. The user

must be aware of data conditions and bear responsibility for the appropriate use of the information with respect to possible errors,

original map scale, collection methodology, currency of data, and other conditions.

4. Users should be aware that temporal changes may have occurred since this data set was collected and that 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 12; TerraModeler Version 12; GeoCue Version 2011.1.20.4 (64-bit);

ESRI ArcGIS 10.0; Global Mapper 13; Optech DashMAP 5.2000

The project area required LiDAR to be collected on 1.0 meter GSD or better and processed to meet a bare earth vertical accuracy of 15.0 centimeters

RMSEz or better.

Data collected to meet 50 cm RMSE.

Deliverables were tested by Photo Science for both vertical and horizontal accuracy. All data is seamless from one tile to the next,

no gaps or no data areas. Although collected on a tile-by-tile basis, breaklines are merged together to produce a single deliverable dataset.

Checks are done to ensure that the data is seamless from one tile to the next before being combined and that breaklines meeting the project

requirements have been collected across the entire project area. The vertical unit of the data file is in decimal meters with

2-decimal point precision. Combining the breaklines with LiDAR data to create other deliverables is another check of the data.

The reported RMSEz value was determined using the calibration control points, and not the Blind Control. The calibration control

points are the same points that were used to remove any bias in the dataset before bare earth editing.

The listed RMSEz value shown below was calculated from the ground (ASPRS Class 2) data in the final Classified LAS file.

; Quantitative Value: 0.09 meters, Test that produced the value: RMSE in meters, as calculated from Classified LAS files

Datasets contain complete coverage of project area and tiles.

Raw Flightlines, Classified LAS files, Breaklines, and Raster DEMs were tested by Photo Science for both vertical and horizontal accuracy.

Although collected on a tile-by-tile basis, breaklines are merged together to produce a single deliverable dataset. Checks are done to ensure that

the data is seamless from one tile to the next before being combined and that breaklines meeting the project requirements have been collected

across the entire project area. Combining the breaklines with LiDAR data to create other deliverables is another check of the data.

All data are seamless from one tile to the next, no gaps or no data areas.