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Short Citation:
OCM Partners, 2023: 2005 FEMA BE Lidar: Ulster County (NY),

Item Identification

Title: 2005 FEMA BE Lidar: Ulster County (NY)
Short Name: ny2005_fema_ulster_be_m5056_metadata
Status: Completed
Publication Date: 2014-08-10

Terrain data, as defined in FEMA Guidelines and Specifications, Appendix N: Data Capture Standards, describe the digital topographic data that were used to create the elevation data representing the terrain environment of a watershed and/or floodplain. Terrain data requirements allow for flexibility in the types of information provided as sources used to produce final terrain deliverables. Once this type of data is provided, FEMA will be able to account for the origins of the flood study elevation data.

NOAA OCM received a delivery from the FEMA Engineering Library which included a point shapefile filled with bare-earth points for the 2005 collection of Ulster County. Within this project was a .ASC DTM file which covered a larger area than the footprint of the shapefile. Ultimately, the smaller footprint was assumed to be validated bare-earth points and processed for public download through the Digital Coast. Final deliverables date to 2007 and cannot be assumed to meet later standards and specifications. Although data review suggests a DEM/DTM product would suffice as the vertical accuracy was tested thoroughly. Be advised that only portions of Ulster County were delivered and OCM is uncertain if more verified and classified data exist.


Terrain data is used to represent the topography of a watershed and/or floodplain environment and to extract useful information for hydraulic and hydrologic models. (Source: FEMA Guidelines and Specs, Appendix N)



Supplemental Information:

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


Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
None Land Surface

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: None Planned
Data Presentation Form: las
Entity Attribute Overview:

LiDAR point data in LAS 1.2 format

ASPRS classification scheme (2 = ground)

Entity Attribute Detail Citation:


Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of PAR Government System, Gomez and Sullivan Engineers, FEMA, Ulster County, NYSDEC, NOAA, the Office for Coastal Management or its partners.

Support Roles

Data Steward

CC ID: 681715
Date Effective From: 2014-08-10
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


CC ID: 681717
Date Effective From: 2014-08-10
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Metadata Contact

CC ID: 681718
Date Effective From: 2014-08-10
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202

Point of Contact

CC ID: 681716
Date Effective From: 2014-08-10
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address:
Phone: (843) 740-1202


Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1137949
W° Bound: -74.783
E° Bound: -73.9114
N° Bound: 42.1811
S° Bound: 41.5794

Extent Group 1 / Time Frame 1

CC ID: 1137948
Time Frame Type: Range
Start: 2005-04-18
End: 2005-05-18

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:;

Data Access Constraints:


Data Use Constraints:

Acknowledgement of FEMA would be appreciated in products derived from these data. This digital data is produced for the purposes of updating/creating a DFIRM database.

Distribution Information

Distribution 1

CC ID: 741866
Download URL:
File Name: Customized Download

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

Distribution 2

CC ID: 741867
Download URL:
File Name: Bulk Download

Simple download of data files.



CC ID: 741869
URL Type:
Online Resource


CC ID: 741870
URL Type:
Online Resource


CC ID: 741871
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz

This graphic shows the lidar coverage for the 2005 FEMA project for the Ulster County area.

Activity Log

Activity Log 1

CC ID: 681732
Activity Date/Time: 2016-10-25

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 681731
Activity Date/Time: 2017-11-14

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

Activity Log 3

CC ID: 718461
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 741868
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Data Quality

Horizontal Positional Accuracy:

The horizontal accuracy is within National Map Accuracy Standards for 1:6,000 scale.; Quantitative Value: 3.6 meters, Test that produced the value: Horizontal accuracy should meet standards listed above of at least 11.9 feet.

Vertical Positional Accuracy:

0.165; Quantitative Value: 0.165 meters, Test that produced the value: An independent Check Point Survey was conducted and used as the basis for establishing this accuracy assessment, according to FEMA Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix A: Guidance for Areial Mapping and Surveying.

The RMSEz for Bare Earth was 0.160 meters.

The RMSEz for the Brush class was 0.164 meters.

The RMSEz for the Forested class was 0.149 meters.

The RMSEz for the High Grass class was 0.166 meters.

The RMSEz for the Urban class was 0.196 meters.

The overall mean was -0.02 meters with an RMSEz of 0.165.

Completeness Report:

Data contained in the Terrain package highlight specific issues in elevation datasets. Terrain data are derived datasets that aid automated hydrologic and hydraulic analyses, the flood hazard area boundary delineations, and quality control.

Conceptual Consistency:

The Terrain package includes flow vectors and non-tiled data (SinkBreach, NoData, VoidData, ExternalBoundary, Island). The Terrain data are consistent with the elevation dataset. A comparison of profile plots with the flow vector data confirms that flow vectors are correctly drawn. Flood hazard boundaries do not extend beyond the External Boundary, if it exists. FIRM panels show the flood hazard area delineations where Island data are present.


Process Steps

Process Step 1

CC ID: 1137945

SinkBreach is a linear spatial file representing sink breaches used to hydrologically correct terrain models. A comparison of flow path automatically generated by a GIS software using elevation data and known flow paths from existing maps and/or orthophotos shows sinks that need to be corrected. NoData, VoidArea, ExternalBoundary and Island are polygon spatial files created by reviewing elevation datasets.

Flood*Ware processes were used to generate a surface model that is sampled at the center of each grid cell. For best results, the Bi-Linear Interpolation function should be used to extract elevations, rather than the standard Nearest-Neighbor function.

The Bare-Earth LIDAR returns and vendor-supplied Break Lines are used to construct the un-corrected DEM using a 3rd-order, inverse distance- weighted Bi-Linear Interopolation over a neighborhood consisting of the twelve closest points within 50 meters of the center of the grid cell.

See Watson, D.F. and Philip, G.M., A Refinement of Inverse Distance Weighted Interpolation. Geo-Processing, 2 315-327, 1985. For Detailed and Limited-Detail Studies the surveyed sections are used to constrct a bed elevation geometery to hydraulically correct the elevation model. The cross sectional area, wetted perimeter, stream slope, manning's N, and hydraulic radius are computed using an iterative numerical integration approach. An hydraulic-based approach is applied along flow tubes to interpolate surveyed bed elevations between surveyed sections. This approach uses a conservation of flow approach to vary the hydralulic radius, wetted perimeter, and cross sectional areas according to measured changes in top width and channel slope. The resulting matrix os bed elevation geometry is then applied to the area within the wetted-perimeter to replace the LIDAR returns from the water surface with the bed elevations. See Reed. C.J., Sanders B., and Lopez-Torrijios, R., LIDAR- Minimum Complements for a Hydraulically Correct Elevation Model Copyright 2003, American Society for Photogrammetry and Remote Sensing, Terrain Data- Applications and Visualization Conference Proceedings.

For all study types, including Redelineation, corrections are made to the Elevation Model as dictated by the Hydarulic Model or the fit of an effective study to the terrain. Where voids in the Bare-earth LIDAR require better definition additonal LIDAR is extracted from the All Returns LIDAR and visaully compared to the Elevation Model. When additional points are deemed to be available in the All Returns the Bare-Earth LIDAR is augmented with the All Returns points and the Elevation Model is rebuilt.

Process Date/Time: 2007-03-27 00:00:00

Process Step 2

CC ID: 1137946

The NOAA Office for Coastal Management (OCM) received a point shapefile containing lidar points without attributes as part of a FEMA delivery. The data was received in UTM Zone 18 in meters and were vertically referenced to NAVD88 using the Geoid03 model in meters. OCM performed the following processing for data storage and Digital Coast provisioning purposes:

1. The shapefile was converted to an LAS 1.2 file with LASTools' shp2las.

2. The LAS files were classified as Class 2 - Ground points.

3. The LAS files were converted from orthometric (NAVD88) heights to ellipsoidal heights using the Geoid03 model.

4. The LAS files were converted from UTM coordinates to Geographic Coordinates in decimal degree.

5. The LAS files were reviewed for outliers and removed accordingly.

Process Date/Time: 2016-07-06 00:00:00

Catalog Details

Catalog Item ID: 49881
GUID: gov.noaa.nmfs.inport:49881
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:22+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+0000
Metadata Record Published: 2022-03-16
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-03-16
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-03-16