Short Citation:
OCM Partners, 2020: 2013-2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New York City), https://www.fisheries.noaa.gov/inport/item/49891.

Item Identification

Title: 2013-2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New York City)
Short Name: ny2014_usgs_cmgp_sandy_nyc_m4920_metadata
Status: Completed
Publication Date: 2015-07-10
Abstract:

TASK NAME: USGS New York CMGP Sandy Lidar 0.7 Meter NPS LIDAR

lidar Data Acquisition and Processing Production Task

USGS Contract No. G10PC00057

Task Order No. G14PD00797

Woolpert Order No. 073666

CONTRACTOR: Woolpert, Inc.

This data set is comprised of lidar point cloud data, raster DEM, hydrologic 3-d breaklines, raster intensity, survey control, project tile index, and project data extent. This task order requires lidar data to be acquired over several areas in New York State to include the entire counties of Bronx, Kings, New York, Richmond, and Queens. Governors, Hoffman, and Swinburne Islands are part of the New York area of interest (AOI), and will be acquired as part of this task order. The total area of the New York Sandy Lidar AOI is approximately 304 square miles. Woolpert acquired lidar data of New York City as part of a task order for the NGA. The flight plan for the New York City NGA Lidar task order was developed with 11 additional cross flights over the Manhattan Metropolitan area to minimize data shadowing and data voids in the lidar dataset caused by tall buildings. The lidar data for the NGA task order was acquired between August 5, 2013 and August 15, 2013. USGS requested use of this data from the NGA, in order to reduce the duplication of lidar data acquisition effort on the New York CMGP Sandy Lidar task order. The NGA approved the use of this lidar data for the USGS task order.Following the approval by NGA, Woolpert was able to utilize the cross flights acquired as part of the NGA task order to minimize data shadowing and data voids caused by tall buildings in the USGS New York CMGP Sandy Lidar task order AOI. The cross flights used in the New York CMGP Sandy 0.7M NPS Lidar Processing task order from the NGA New York City task order were flown on August 6, 2013. The lidar data acquisition parameters for this mission are detailed in the lidar processing report for this task order. The lidar data will be acquired and processed under the requirements identified in this task order. lidar data is a remotely sensed high resolution elevation data collected by an airborne platform. The lidar sensor uses a combination of laser range finding, GPS positioning, and inertial measurement technologies. The lidar systems collect data point clouds that are used to produce highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures, and vegetation. The task required the LiDAR data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. The final products include classified LAS, one (1) meter pixel raster DEMs of the bare-earth surface in ERDAS IMG Format, and 8-bit intensity images. Each LAS file contains lidar point information, which has been calibrated, controlled, and classified. Additional deliverables include hydrologic breakline data, control data, tile index, lidar processing and survey reports in PDF format, FGDC metadata files for each data deliverable in .xml format, and LAS swath data. Collected swath files that were that were larger than 2GB were provided in multiple sub-swath files, each less than 2GB. Ground conditions: Water at normal levels; no unusual inundation; no snow; leaf off. The tide window requirements for the lidar data acquisition; Tidally impacted waters within the AOI are expected to be acquired at Predicted MLW +- 2 hours exclusive of neap tide.; The bare earth DEMs along the coast may have a variance in the water heights due to temporal differences during the lidar data acquisition and will be represented in DEM as a seam-like anomaly.; One coastal elevation was applied to entire project area. Due to differing acquisition dates and thus differing tide levels there will be areas in the DEM exhibiting what appears to be "digging" water features. Sometimes as much as approximately 1 meter. This was done to ensure that no coastal hydro feature was "floating" above ground surface. This coastal elevation will also affect connected river features wherein a sudden increase in flow will be observed in the DEM to accommodate the coastal elevation value; During Hydrologic breakline collection, Woolpert excluded obvious above-water piers or pier-like structures from the breakline placement. Some features extend beyond the apparent coastline and are constructed in a manner that can be considered an extension of the ground. These features were treated as ground during classification and subsequent hydrologic delineation. In all cases, professional practice was applied to delineate what appeared to be the coast based on data from multiple sources; Due to the many substructures and the complexity of the urban environment, interpolation and apparent "divots" (caused by tinning) may be evident in the surface of the bare earth DEM. In all cases, professional practice was applied to best represent the topography.

NOAA OCM has not received any finalized DEMs for this project and do not expect to, therefore any request for these should be directed to USGS' National Map or a contact at Woolpert directly (as listed below).

Purpose:

The lidar data will be acquired and processed under the requirements identified in this task order. This data will assist in the evaluation of storm damage and erosion of the local environment as part of USGS' Hurricane Sandy response.

Notes:

10535

Supplemental Information:

A footprint of this data set may be viewed in Google Earth at: https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/4920/supplemental/ny2014_usgs_cmgp_sandy_nyc_m4920.kmz

A map showing the Nominal Point Spacing for each area of the project may be viewed here:

https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/4920/supplemental/ny2014_usgs_cmgp_sandy_nyc_m4920_lidarreport.pdf.

Keywords

Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category elevation
None Elevation
None LiDAR
None Model
None Remote Sensing
None Topography/Bathymetry

Spatial Keywords

Thesaurus Keyword
None New York
None New York City
None US

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: As Needed
Data Presentation Form: las
Entity Attribute Overview:

LiDAR points in LAS format (ASPRS Classes 1,2,7,9,10,17,18)

Entity Attribute Detail Citation:

none

Distribution Liability:

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

Support Roles

Data Steward

CC ID: 682117
Date Effective From: 2015-07-10
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 682119
Date Effective From: 2015-07-10
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 682120
Date Effective From: 2015-07-10
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 682118
Date Effective From: 2015-07-10
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 682133
W° Bound: -74.258875
E° Bound: -73.69909
N° Bound: 40.9177328
S° Bound: 40.4953623

Extent Group 1 / Time Frame 1

CC ID: 682122
Time Frame Type: Discrete
Start: 2013-08-06

Extent Group 1 / Time Frame 2

CC ID: 682123
Time Frame Type: Discrete
Start: 2014-03-21

Extent Group 1 / Time Frame 3

CC ID: 682124
Time Frame Type: Discrete
Start: 2014-03-22

Extent Group 1 / Time Frame 4

CC ID: 682125
Time Frame Type: Discrete
Start: 2014-03-23

Extent Group 1 / Time Frame 5

CC ID: 682126
Time Frame Type: Discrete
Start: 2014-03-26

Extent Group 1 / Time Frame 6

CC ID: 682127
Time Frame Type: Discrete
Start: 2014-03-27

Extent Group 1 / Time Frame 7

CC ID: 682128
Time Frame Type: Discrete
Start: 2014-03-31

Extent Group 1 / Time Frame 8

CC ID: 682129
Time Frame Type: Discrete
Start: 2014-04-01

Extent Group 1 / Time Frame 9

CC ID: 682130
Time Frame Type: Discrete
Start: 2014-04-06

Extent Group 1 / Time Frame 10

CC ID: 682131
Time Frame Type: Discrete
Start: 2014-04-19

Extent Group 1 / Time Frame 11

CC ID: 682132
Time Frame Type: Discrete
Start: 2014-04-21

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Access Information

Security Class: Unclassified
Data Access Procedure:

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

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4920;

Data Access Constraints:

None

Data Use Constraints:

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. These data depict the heights at the time of the survey and are only accurate for that time.

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.

Distribution Information

Distribution 1

CC ID: 741924
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4920
Distributor:
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

Distribution 2

CC ID: 741925
Download URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/4920
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 741927
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 741928
URL: https://coast.noaa.gov
URL Type:
Online Resource

URL 3

CC ID: 741929
URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/4920/supplemental/ny2014_usgs_cmgp_sandy_nyc_m4920.kmz
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic shows the lidar coverage for the 2014 lidar acquisition for New York City.

URL 4

CC ID: 795135
URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/4920/supplemental/Lidar_Rpt_NYSandy_Lidar_October_2014.pdf
Name: Project report
URL Type:
Online Resource
File Resource Format: pdf

URL 5

CC ID: 795136
URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12b/data/4920/supplemental/NY_CMGP_Sandy_Lidar_Survey_Control_Report_final.pdf
Name: Survey report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Survey report, including pictures of ground control and validation survey locations.

Activity Log

Activity Log 1

CC ID: 682144
Activity Date/Time: 2017-03-20
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 682143
Activity Date/Time: 2017-11-14
Description:

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 718471
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 741926
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Data Quality

Horizontal Positional Accuracy:

Compiled to meet 0.42 meters horizontal accuracy at 95 percent confidence level.; Quantitative Value: 0.42 meters, Test that produced the value: lidar system specifications are available in the project report

Vertical Positional Accuracy:

LAS data covering the USGS New York CMGP Sandy Lidar 0.7 Meter NPS Lidar Task Order was compared to independent survey control points to determine the FVA of the LAS Swath and of the Bare-Earth DEM. In addition, this LAS data was compared to independent supplemental points from categories: Bare Earth Open Terrain, and Urban. LAS Swath Fundamental Vertical Accuracy (FVA) Tested 0.113 meters fundamental vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using 0.058 meters (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines. Bare-Earth DEM Fundamental Vertical Accuracy (FVA) Tested 0.121 meters fundamental vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using 0.062 meters (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.; Quantitative Value: 0.113 meters, Test that produced the value: LAS Swath Fundamental Vertical Accuracy (FVA) Tested 0.113 meters fundamental vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the TIN.; Quantitative Value: 0.121 meters, Test that produced the value: Bare-Earth DEM Fundamental Vertical Accuracy (FVA) Tested 0.121 meters fundamental vertical accuracy at a 95 percent confidence level, derived according to NSSDA, in open terrain using (RMSEz) x 1.96000 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the DEM.; Quantitative Value: 0.116 meters, Test that produced the value: Urban Land Cover Classification Supplemental Vertical Accuracy (SVA) Tested 0.116 meters supplemental vertical accuracy at the 95th percentile in the Urban supplemental class reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the DEM. Urban Errors larger than 95th percentile include:

Point 3010, Easting 607295.08, Northing 4510823.43, Z-Error 0.120 meters

Point 3013, Easting 600685.99, Northing 4502554.14, Z-Error 0.130 meters

; Quantitative Value: 0.116 meters, Test that produced the value: Consolidated Vertical Accuracy (CVA) Tested 0.116 meters consolidated vertical accuracy at the 95th percentile level; reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines and tested against the DEM. CVA is based on the 95th percentile error in all land cover categories combined.

Point 2008, Easting 600936.95, Northing 4524448.32, Z-Error 0.120 meters

Point 3010, Easting 607295.08, Northing 4510823.43, Z-Error 0.120 meters

Point 3013, Easting 600685.99, Northing 4502554.14, Z-Error 0.130 meters

Completeness Report:

The lidar data is visually inspected for completeness to ensure that are no void areas or missing data.

Conceptual Consistency:

All formatted data cover the entire area specified for this project and are validated using a combination of commercial lidar processing software, GIS software, and proprietary programs to ensure proper formatting and loading prior to delivery.

Lineage

Process Steps

Process Step 1

CC ID: 682103
Description:

Using two Leica ALS70 (lidar) systems on board a Cessna 404 and Cessna 310 aircraft, lidar data, at a nominal pulse spacing (NPS) of 0.7 meters, was collected for this task order (approximately 304 square miles). AGL = 7500 feet - Aircraft Speed = 150 Knots, Field of View (Full) = 32 degrees, Pulse Rate = 239 kHz, Scan Rate = 41.6 Hz, with an average side lap of 25%. Multiple returns were recorded for each laser pulse along with an intensity value for each return. This acquisition was part of a larger effort designed to capture one other USGS task order AOI in New Jersey. For the New York portion of the collection, ten (10) missions were flown between March 21, 2014 and April 21, 2014. Six (6) Global Navigation Satellite System (GNSS) Base Stations were used in support of the lidar data acquisition. Specific information regarding latitude, longitude, and ellipsoid height to the L1 phase center is included in the lidar processing report. As a supplement to the USGS task order collection, Woolpert acquired lidar data of New York City as part of a 2013 task order for the NGA. This was acquired using a Leica ALS70 (lidar) system on board a Cessna 404 and produced lidar data, at a nominal pulse spacing (NPS) of 0.91 meters. AGL = 7500 feet - Aircraft Speed = 150 Knots, Field of View (Full) = 40 degrees, Pulse Rate = 239 kHz, Scan Rate = 36.9 Hz, with an average side lap of 30%. For the NGA task order portion of the collection One (1) mission was used. This mission was flown on August 6, 2013. One (1) Global Navigation Satellite System (GNSS) Base Station was used in support of the lidar data acquisition. Specific information regarding latitude, longitude, and ellipsoid height to the L1 phase center is included in the lidar processing report. Multiple returns were recorded for each laser pulse along with an intensity value for each return. The flight plan for the New York City NGA Lidar task order was developed with 11 additional cross flights over the Manhattan Metropolitan area to minimize data shadowing and data voids in the lidar dataset caused by tall buildings. USGS requested use of this data from the NGA in order to reduce the duplication of lidar data acquisition effort on the New York CMGP Sandy Lidar task order.

Process Date/Time: 2014-03-22 00:00:00

Process Step 2

CC ID: 682104
Description:

The NGA approved the use of this lidar data for the USGS task order. Following the approval by NGA, Woolpert was able to utilize the cross flights acquired as part of the NGA task order to minimize data shadowing and data voids caused by tall buildings in the USGS New York CMGP Sandy Lidar task order AOI. The lidar data acquisition parameters for this mission are detailed in the lidar processing report for this task order. For all acquired lidar data as part of entire USGS New York City task order, the geoid used to reduce satellite derived elevations to orthometric heights was GEOID12A. Data for the task order is referenced to the UTM Zone 18N, North American Datum of 1983 (2011), and NAVD88, in meters. Once the data acquisition and GPS processing phases are complete, the lidar data was processed immediately to verify the coverage had no voids. The GPS and IMU data was post processed using differential and Kalman filter algorithms to derive a best estimate of trajectory. The quality of the solution was verified to be consistent with the accuracy requirements of the project. The SBET was used to reduce the lidar slant range measurements to a raw reflective surface for each flight line. The coverage was classified to extract a bare earth digital elevation model (DEM) and separate last returns. The ALS70 calibration and system performance is verified on a periodic basis using Woolpert's calibration range. The calibration range consists of a large building and runway. The edges of the building and control points along the runway have been located using conventional survey methods. Inertial measurement unit (IMU) misalignment angles and horizontal accuracy are calculated by comparing the position of the building edges between opposing flight lines. The scanner scale factor and vertical accuracy is calculated through comparison of lidar data against control points along the runway. Field calibration is performed on all flight lines to refine the IMU misalignment angles. IMU misalignment angles are calculated from the relative displacement of features within the overlap region of adjacent (and opposing) flight lines. The raw lidar data is reduced using the refined misalignment angles.

Process Date/Time: 2014-03-22 00:00:00

Process Step 3

CC ID: 682105
Description:

Ground control and QAQC control point survey was performed by Woolpert surveyors, to support the USGS New York CMGP Sandy Lidar 0.7 Meter NPS LIDAR project. All surveys were performed in such a way as to achieve ground control that supports lidar data at 9.25 cm RMSE accuracy and satisfy a local network accuracy of 5 cm at a 95% confidence level. All ground control survey field activities took place from 12/03/2013 thru 05/07/14. Woolpert collected control data for data processing as supplemental QAQC points. The supplemental QAQC points were collected to be used in independent accuracy testing. The survey was performed using two (2) Trimble Navigation R8 Model 3 GNSS Dual Frequency GPS receivers with a Trimble TDL-450 radio as dual base stations in conjunction with simultaneous data collected across two (2) Continuously Operating Reference Stations (CORS) GPS receivers. Additionally, Woolpert utilized a Trimble Navigation R8 Model 3 GNSS dual-frequency GPS receiver and a TSC2 data collector as a rover. Woolpert surveyors,utilizing Real-Time Kinematic GPS techniques, made observations using 1-second epoch rates and observations of 60 to 180 seconds. Each station was occupied twice to insure necessary horizontal and vertical accuracies. All GPS ground control observations were processed using Trimble Navigation's Trimble Business Center. All horizontal GPS control was based on UTM Zone 18N, NAD83(2011) expressed in meters. The vertical datum used for this project was based on the North American Vertical Datum of 1988 (NAVD88), GEOID12A, also expressed in meters.

Process Date/Time: 2013-12-03 00:00:00

Process Step 4

CC ID: 682106
Description:

The individual flight lines were inspected to ensure the systematic and residual errors have been identified and removed. Then, the flight lines were compared to adjacent flight lines for any mismatches to obtain a homogeneous coverage throughout the project area. The point cloud underwent a classification process to determine bare-earth points and non-ground points utilizing "first and only" as well as "last of many" lidar returns. This process determined Default (Class 1), Ground (Class 2), Noise (Class 7), Water (Class 9), Ignored Ground (Class 10), Overlap Default (Class 17) and Overlap Ground (Class 18). The bare-earth (Class 2 - Ground) lidar points underwent a manual QA/QC step to verify the quality of the DEM as well as a peer-based QC review. This included a review of the DEM surface to remove artifacts and ensure topographic quality. Classification of water (class 9) and ignored ground (class 10) was completed via the use of the hydrologic breaklines collected for the hydro-flattening phase. The overlap classes were determined by first identifying the overlapping areas and reclassifying the LAS data by offset from a corridor. This allows the returns located on the edge of the swath to be removed from the bare earth coverage in an effort to produce a more uniform data density. The returns determined to be overlap are then further classified to produce overlap default (class 17) and overlap ground (class 18). The surveyed ground control points are used to make vertical adjustments to the data set and to perform the accuracy checks and statistical analysis of the lidar dataset. Supervisory QC monitoring of work in progress and completed editing ensured consistency of classification character and adherence to project requirements across the entire project area. The resulting deliverables for this task order consist of classified LAS file in LAS 1.2 format, Raw Swath LAS files in LAS 1.2 format, 1 meter pixel size DEM files in ERDAS IMG format, 1 meter pixel size 8-bit Intensity files in GeoTIFF format, and Hydrologic Breakline data in ESRI shape file format.

Process Date/Time: 2014-03-22 00:00:00

Process Step 5

CC ID: 682107
Description:

The individual flight lines were inspected to ensure the systematic and residual errors have been identified and removed. Then, the flight lines were compared to adjacent flight lines for any mismatches to obtain a homogeneous coverage throughout the project area. The point cloud underwent a classification process to determine bare-earth points and non-ground points utilizing "first and only" as well as "last of many" lidar returns. This process determined Default (Class 1), Ground (Class 2), Noise (Class 7), Water (Class 9), Ignored Ground (Class 10), Overlap Default (Class 17) and Overlap Ground (Class 18). The bare-earth (Class 2 - Ground) lidar points underwent a manual QA/QC step to verify the quality of the DEM as well as a peer-based QC review. This included a review of the DEM surface to remove artifacts and ensure topographic quality. Classification of water (class 9) and ignored ground (class 10) was completed via the use of the hydrologic breaklines collected for the hydro-flattening phase. The overlap classes were determined by first identifying the overlapping areas and reclassifying the LAS data by offset from a corridor. This allows the returns located on the edge of the swath to be removed from the bare earth coverage in an effort to produce a more uniform data density. The returns determined to be overlap are then further classified to produce overlap default (class 17) and overlap ground (class 18). The surveyed ground control points are used to make vertical adjustments to the data set and to perform the accuracy checks and statistical analysis of the lidar dataset. Supervisory QC monitoring of work in progress and completed editing ensured consistency of classification character and adherence to project requirements across the entire project area. The hydrologic breaklines were produced according to USGS version 1.0 specifications. The compilation procedure included use of lidar intensity, bare earth surface model, point cloud data, open source imagery in an effort to manually compile hydrologic features in a 2-d environment. Following the compilation phase, a separate process was used to adjust the breakline data to best match the water level at the time of the lidar collection. Any ponds and/or lakes were adjusted to be at or just below the bank and to be at a constant elevation. Any streams were adjusted to be at or just below the bank and to be monotonic. Manual QAQC and peer-based QC review was performed on all delineated data to ensure horizontal placement quality and on all adjusted data to ensure vertical placement quality. The final hydrologic breakline product was delivered in ESRI shape file format and was also used in the processing of the DEM deliverable.

Process Date/Time: 2014-03-22 00:00:00

Process Step 6

CC ID: 682108
Description:

Tile Size: 1,500m x 1,500m. The tile file name was derived from the southwest corner of each tile. The tiles are named based on the US National Grid. Project data extent was provided by USGS and subsequently buffered by 100 meters and provided in shape file format. Project deliverables were clipped to the 100 meter data extent.

Process Date/Time: 2014-03-22 00:00:00

Process Step 7

CC ID: 682109
Description:

The NOAA Office for Coastal Management (OCM) received the topographic files in classified LAS format from USGS' ftp site (ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/USGS_Lidar_Point_Cloud_NY_CMPG_2013_LAS_2015/). The data were received in UTM Zone 18N NAD83(2011) coordinates (meters) and vertically referenced to NAVD88 using the Geoid12a model in meters. OCM performed the following processing for data storage and Digital Coast provisioning purposes:

1. LAS files were compressed to LAZ format with laszip.

2. Duplicate points were removed using LAStools' lasduplicate.

3. The LAZ files were transformed to geographic (decimal degrees), ellipsoidal coordinates (meters). The transform to ellipsoidal coordinates was done by reversing the application of the GEOID12a model from a previous processing step.

4. Points that fell well outside the project bounds were eliminated. Many of these points had impossible coordinates. Files affected included 18TWL940255.laz, 18TXL075120.laz, and 18TWL880060.laz. File 18TWL940255.laz had no points left after eliminating out of bounds points and was deleted.

Process Date/Time: 2018-10-31 00:00:00
Process Contact: Office for Coastal Management (OCM)

Catalog Details

Catalog Item ID: 49891
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:23+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2019-07-02 15:17+0000
Metadata Record Published: 2018-03-13
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2019-03-14