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OCM Partners, 2024: 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: North Puget Sound Lowlands,

Item Identification

Title: 2005 Puget Sound LiDAR Consortium (PSLC) Topographic LiDAR: North Puget Sound Lowlands
Short Name: wa2005_pslc_northpugetlowlands_m2579_metadata
Status: Completed
Publication Date: 2013-10-29

Terrapoint collected Light Detection and Ranging (LiDAR) data contributing to the Puget Sound Lowlands project of 2005. Arlington, City of Snohomish, Snohomish Floodplains, Lummi-Nooksack, Nooksack North Fork, Marysville, Port Susan and Fisher Slough, Skagit Environmental Bank, Cavanaugh, Sauk South, Sauk South, Sauk-Suiattle, Skagit Bacon, Edmonds, Mt. Lake Terrace and Mukilteo of Central and North Central Washington. This data set covers approximately 5,285 square miles.

The Airborne LiDAR survey was conducted using Terrapoint's 40 kHz ALTMS (Airborne Laser Terrain Mapping System), flying at an optimum height of 3500 ft AGL at 140 knots. The system consists of a 36-degree full angle laser, a Trimble 4700 GPS receiver and a Honeywell H764 IMU unit. This metadata is a collaboration of metadata reports from each of the individual 15 projects. The Puget Sound Lowlands project covers more areas over 2000-2004, these areas were excluded for this project.


The LAS files can be used to create DEMs and also to extract topographic data in software that does not support raster data. Other surface features can also be extracted with custom applications. LiDAR data has a wide range of

uses such as earthquake hazard studies, hydrologic modeling, forestry, coastal engineering, roadway and pipeline engineering, flood plain mapping, wetland studies, geologic studies and a variety of analytical and cartographic




Supplemental Information:

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

Reports explaining collection and quality assurance is available at:

A PSLC shapefile containing the individual projects which were combined for this project is available at:

Individual report collaborations:

project, area (sq mi), date(s) collected, vert. acc (cm), horiz acc. (cm), RMSE (m) - Arlington 10, 2/23/2005-2/26/2005, 25, 60, 0.063 - City of Snohomish, 6, 2/26/2005, 25, 60, 0.075 - Snohomish Floodplains, 118, 2/23/2005-2/26/2005, 0.064 - Lummi-Nooksack, 3,4/20/2005, 25, 60, 0.053 - Nooksack North Fork, 21.5, 3/23/2005, 25, 60, 0.031 - Marysville, 34, 5/15/2005-6/15/2005, 25, 60, 0.063 - Port Susan (PS) and Fisher Slough (FS), 41 (FS 18.5) (PS 22.5), 3/15/2005-4/15/2005, 25, 60, FS 0.076 + PS 0.086 - Skagit Environmental Bank, 1.26, 4/6/2005, 25, 60, 0.092 - Cavanaugh, 62, 4/6/2005-4/10/2005, 25, 60, 0.046 - Sauk North, 42, 4/10/2005-4/19/2005, 25, 60, 0.055 - Sauk South, report not available - Sauk-Suiattle, 8, 4/10/2005-4/19/2005, 25, 60, 0.055 - Skagit Bacon, 13, 4/8/2005-4/10/2005, 25, 60, 0.057 - Edmonds, 11, 2/27/2005, 25, 60, 0.100 - Mt. Lake Terrace, 4, 7/15/2005-9/15/2005, 25, 60, 0.100 - Mukilteo, 16, 2/27/2005, 25, 60, 0.100


Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
None LAZ

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 LAZ format (ASPRS Classes 1,2,7)

Entity Attribute Detail Citation:


Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility

of Terrapoint, PSLC, NOAA, the Office for Coastal Management or its partners.

Data Set Credit: Please credit the Puget Sound LiDAR Consortium (PSLC) for these data. The PSLC is supported by the Puget Sound Regional Council, the National Aeronautical and Space Administration (NASA), the United States Geological Survey (USGS) and numerous partners in local, state, and tribal government.

Support Roles

Data Steward

CC ID: 692302
Date Effective From: 2013-10-29
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: 692304
Date Effective From: 2013-10-29
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: 692305
Date Effective From: 2013-10-29
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: 692303
Date Effective From: 2013-10-29
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: 1134739
W° Bound: -122.78552883
E° Bound: -121.3209672
N° Bound: 48.93129584
S° Bound: 47.77733809

Extent Group 1 / Time Frame 1

CC ID: 1134738
Time Frame Type: Range
Start: 2004-11-11
End: 2005-07-15

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:

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.

Distribution Information

Distribution 1

CC ID: 743306
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: 743307
Download URL:
File Name: Bulk Download

Simple download of data files.



CC ID: 743309
URL Type:
Online Resource


CC ID: 743310
URL Type:
Online Resource


CC ID: 743311
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz

This graphic shows the lidar coverage for the 2005 North Puget Sound Lowlands area of Washington.

Activity Log

Activity Log 1

CC ID: 692325
Activity Date/Time: 2016-05-23

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 692324
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: 718754
Activity Date/Time: 2018-02-08

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 743308
Activity Date/Time: 2018-03-13

Partial upload to move data access links to Distribution Info.

Data Quality


Elevations are recorded in floating-point meters and the vertical datum is ellipsoidal (GEOID03). There are no other attribute tables.

Horizontal Positional Accuracy:

Horizontal positional accuracy for LiDAR is dependent upon

the quality of the GPS/INS solution, sensor calibration and ground conditions at the time of

data capture. The standard system results for horizontal accuracy are less than 1 meter.

; Quantitative Value: 0.60 meters, Test that produced the value:

Reporting highest reported values with uncertainty of likelihood of less than 0.60 m horizontal accuracy

values. 20 - 60 centimeters on all but extremely hilly terrain.

Vertical Positional Accuracy:

Laser point returns were optimized for internal consistency based on independent data from the LiDAR system, IMU, and aircraft. Noise points (e.g. pits and birds) were filtered from the data based on known elevation ranges. This data was then compared to 10,000+ real time kinematic ground survey points collected to verify the vertical and horizontal accuracies of the data set.; Quantitative Value: 0.25 meters, Test that produced the value: Averaged to 25 cm. 10-15 centimeters on Hard Surfaces (roads and buildings), 15-25 centimeters on Soft/Vegetated Surfaces (flat to rolling terrain), 25-40 centimeters on Soft/Vegetated Surfaces (hilly terrain)

Completeness Report:

LiDAR data has been collected and processed for all areas within the project study area.

Conceptual Consistency:

LiDAR flight lines have been examined to ensure that there was at least 50% sidelap, there are no gaps between flightlines, and overlapping flightlines have consistent elevation values.

Shaded relief images have been visually inspected for data errors such as pits, border artifacts, gaps, and shifting. The data was examined at a 1:3500 scale.


Process Steps

Process Step 1

CC ID: 1134734

Point Generation.

The points are generated as Terrascan binary Format using Terrapoint's proprietary Laser Postprocessor Software. This software combines the Raw Laser file and GPS/IMU information to generate a point cloud for each individual flight. All the point cloud files encompassing the project area were then divided into quarter quad tiles. The referencing system of these tiles is based upon the project boundary minimum and maximums. This process is carried out in Terrascan.

The bald earth is subsequently extracted from the raw LiDAR points using Terrascan in a Microstation environment. The automated vegetation removal process takes place by building an iterative surface model. This surface model is generated using three main parameters: Building size, Iteration angle and Iteration distance.

The initial model is based upon low points selected by a roaming window and are assumed to be ground points. The size of this roaming window is determined by the building size parameter. These low points are triangulated and the remaining points are evaluated and subsequently added to the model if they meet the Iteration angle and distance constraints (fig. 1). This process is repeated until no additional points are added within an iteration.

There is also a maximum terrain angle constraint that determines the maximum terrain angle allowed within the model.

Multiple process dates.

Process Step 2

CC ID: 1134735


1. Flight lines and data were reviewed to ensure complete coverage of the study area and positional accuracy of the laser points.

2. Laser point return coordinates were computed using the REALM survey suite and PosPac based on independent data from the LiDAR system, IMU, and aircraft.

3. The raw LiDAR file was assembled into flight lines per return with each point having an associated x, y, and z coordinate.

4. Visual inspection of swath to swath laser point consistencies within the study area were used to perform manual refinements of system alignment.

5. Custom algorithms were designed to evaluate points between adjacent flight lines. Automated system alignment was computed based upon randomly selected swath to swath accuracy measurements that

consider elevation, slope, and intensities. Specifically, refinement in the combination of system pitch, roll and yaw offset parameters optimize internal consistency.

6. Noise (e.g., pits and birds) was filtered using REALM software tools based on known elevation ranges and included the removal of any cycle slips.

7. Using TerraScan and Microstation, ground classifications utilized custom settings appropriate to the study area.

8. The corrected and filtered return points were compared to the RTK ground survey points collected to verify the vertical and horizontal accuracies.

9. Points were broken into processing bins and output areas and output as laser points, TINed and GRIDed surfaces. Bare earth DEMs meet PSLC specifications.

Process Step 3

CC ID: 1134736

The NOAA Office for Coastal Management (OCM) downloaded topographic files in .txt format from PSLC's website. The files contained lidar elevation, intensity, return number, class, scan angle and GPS time

measurements. The data were received in Washington State Plane North Zone 4601, NAD83 coordinates and were vertically referenced to NAVD88 using the Geoid03 model. The vertical units of the data were

feet. OCM performed the following processing for data storage and Digital Coast provisioning purposes:

1. The All-Return ASCII txt files were parsed to convert GPS Week Time to Adjusted Standard GPS Time.

2. The All-Return ASCII files were converted from txt format to las format using LASTools' txt2las tool and reclassified to fit the OCM class list, N=1, G=2, V=1, B=7. Vegetation points were set to "unclassified" due to the uncertainty of all vegetation points falling into one category rather than low, medium or high vegetation.

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

4. The las files' vertical units were converted from feet to meters.

5. The las files were converted from a Projected Coordinate System (WA SP North) to a Geographic Coordinate system (NAD83)

6. The las files' horizontal units were converted from feet to decimal degrees and converted to laz format.

Process Date/Time: 2013-10-01 00:00:00

Catalog Details

Catalog Item ID: 50149
GUID: gov.noaa.nmfs.inport:50149
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:24+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