Short Citation:
Office for Coastal Management, 2021: 2012 NOAA American Samoa Lidar DEM: Islands of Tutuila, Aunu'u, Ofu, Olosega, Ta'u and Rose Atoll, https://www.fisheries.noaa.gov/inport/item/52876.

Item Identification

Title: 2012 NOAA American Samoa Lidar DEM: Islands of Tutuila, Aunu'u, Ofu, Olosega, Ta'u and Rose Atoll
Short Name: 2012 AmSam DEM
Status: Completed
Publication Date: 2013-06
Abstract:

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 American Samoa including the islands of Tutuila, Aunu'u, Ofu, Olosega, Ta'u and Rose Atoll.

The project area consists of approximately 75 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). GMR Aerial Surveys Inc. d/b/a Photo Science, Inc.

acquired 108 flight lines in 7 lifts between June 2012 and July 2012. This collection was for NOAA Office for Coastal Management (OCM).

The data collection was performed with a Beechcraft King Air 90 twin engine aircraft (tail number N87E) utilizing an Optech Gemini

sensor; collecting multiple return x, y, and z as well as intensity data. The data were provided to OCM, classified as:

Unclassified (1), Ground (2), Low Point (Noise) (7), Water (9), Breakline Edge (10), Overlap Unclassified (17) and Overlap Ground (18).

The classifications available for download from the Digital Coast are:

Unclassified (1), Ground (2), Low Point (Noise) 7, Water (9), Removed Ground (breakline edge) (10), and Overlap (12).

The collection conditions were cloud and fog-free between the aircraft and the ground; streams must be within their banks; and

low tide acquisition if at all possible.

Data voids within a single swath were avoided whenever possible. Acceptable void areas are caused by a water body;

areas of low near infrared (NIR) reflectivity such as asphalt or composition roofing and where appropriately filled in by another swath.

Unfortunately, during the LiDAR acquisition there were a few mountain peaks where the clouds never lifted high enough to collect LiDAR.

In order to post process the LiDAR data to meet task order specifications, Photo Science, Inc. established control points that

were used to calibrate the LiDAR to known ground locations established on Tutuila. Please see the survey report for more details on

ground control point collection at:

https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/2490/supplemental/PhotoScience-AmSam_PostFlightAcquisitionReport_FINAL.pdf

The dataset was developed based on a horizontal projection/datum of UTM NAD83 (PACP00), UTM Zone 2, meters. The vertical datum

used during the collection, varied by island. NAVD88 (ASVD02), meters was used for the island of Tutuila (and Aunu'u). NAVD1988

(GEOID09), meters was used for the islands of Ofu, Olosega and Tau. Rose atoll was adjusted from Ellipsoid heights to a mean

low water (MLW) datum.

Purpose:

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

Charleston, SC to collect and deliver topographic elevation point data derived from multiple return light detection

and ranging (LiDAR) measurements for American Samoa including islands of Tutila, Aunu'u, Ofu, Olosega, Ta'u and Rose Atoll.

Data are intended for use in coastal management decision making.

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.

Supplemental Information:

There were seven lifts flown out of Pago Pago International Airport for Tutuila and Aunuu and Fitiuta Airport for Ofu, Olosega,

Tau and Rose Atoll collection.

Base stations were set up at the airports and sensor Serial Number 246 was used for all flights:

June 25, 2012 A

June 25, 2012 B

June 25, 2012 C

June 27, 2012

July 5, 2012 A

July 5, 2012 B

July 5, 2012 C

The Post Flight Aerial Acquisition and Calibration Report may be accessed at:

https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/2490/supplemental/PhotoScience-AmSam_PostFlightAcquisitionReport_FINAL.pdf

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

https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/2490/supplemental/2012_NOAA_American_Samoa_Lidar.kmz

Keywords

Theme Keywords

Thesaurus Keyword
UNCONTROLLED
Global Change Master Directory (GCMD) Science Keywords Earth Science > Land Surface > Topography > Terrain Elevation > Topographical Relief Maps
Global Change Master Directory (GCMD) Science Keywords Earth Science > Oceans > Coastal Processes > Coastal Elevation
ISO 19115 Topic Category elevation
None Bathymetry/Topography
None breaklines
None DEM
None elevation
None LiDAR
None model
None Raster
None remote sensing

Spatial Keywords

Thesaurus Keyword
UNCONTROLLED
Global Change Master Directory (GCMD) Location Keywords Ocean > Pacific Ocean > Central Pacific Ocean > American Samoa
None American Samoa
None Aunu'u
None Ofu
None Olosega
None Rose Atoll
None Ta'u
None Tutuila
None United States

Physical Location

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

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: Unknown
Distribution Liability:

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

Support Roles

Data Steward

CC ID: 757914
Date Effective From: 2013-06
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: 757916
Date Effective From: 2013-06
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: 757917
Date Effective From: 2013-06
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: 757915
Date Effective From: 2013-06
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: 757912
W° Bound: -170.851652
E° Bound: -168.132827
N° Bound: -14.152104
S° Bound: -14.564143

Extent Group 1 / Time Frame 1

CC ID: 757909
Time Frame Type: Discrete
Start: 2012-06-25

Extent Group 1 / Time Frame 2

CC ID: 757910
Time Frame Type: Discrete
Start: 2012-06-27

Extent Group 1 / Time Frame 3

CC ID: 757911
Time Frame Type: Discrete
Start: 2012-07-05

Spatial Information

Spatial Representation

Representations Used

Grid: Yes

Grid Representation 1

CC ID: 757932
Dimension Count: 2
Cell Geometry: Point
Transformation Parameters Available?: Yes

Axis Dimension 1

Dimension Type: Row
Size: 1000
Resolution Type: Length
Resolution: 1.0 Meter

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=8543

This data set is dynamically generated based on user-specified parameters.

;

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.

Distribution Information

Distribution 1

CC ID: 757918
Start Date: 2018-06-27
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8543
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2013-06 - Present)
File Name: Customized Download
Description:

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

Compression: Zip

Distribution 2

CC ID: 757919
Start Date: 2018-06-27
End Date: Present
Download URL: https://coast.noaa.gov/htdata/raster2/elevation/AmSam_DEM_2012_8543
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2013-06 - Present)
File Name: Bulk Download
Description:

Simple download of data files.

File Type: GeoTIFF
Compression: no compression applied

URLs

URL 1

CC ID: 757922
URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/2490/supplemental/2012_NOAA_American_Samoa_Lidar.kmz
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic shows the lidar coverage for the American Samoa lidar.

URL 2

CC ID: 757934
URL: https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/2490/supplemental/PhotoScience-AmSam_PostFlightAcquisitionReport_FINAL.pdf
Name: Acquisition report
URL Type:
Online Resource
File Resource Format: pdf
Description:

Report by PhotoScience covering data acquisition.

Activity Log

Activity Log 1

CC ID: 757924
Activity Date/Time: 2016-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 757923
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: 757925
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 757926
Activity Date/Time: 2018-03-13
Description:

Partial upload to move data access links to Distribution Info.

Technical Environment

Description:

MicroStation Version 8; TerraScan Version 12; TerraModeler Version 12; GeoCue Version 2012;

ESRI ArcGIS 10.1; Global Mapper 14.1; Optech DashMAP 5.2000

Data Quality

Accuracy:

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.

Horizontal Positional Accuracy:

Collected to meet four feet RMSE or better.

Vertical Positional Accuracy:

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 islands control were measured with Ofu and Olosega; Tau; and Tutuila and Aunuu. The RMSE for each island:

Ofu and Olosega RMSE 0.074 m.

Tau RMSE 0.072 m.

Tutuila and Aunuu RMSE 0.067 m.

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

and is an average of the above RMSE values.

; Quantitative Value: 0.071 meters, Test that produced the value: RMSE in meters, as calculated from Classified LAS files

Completeness Report:

Datasets contain complete coverage of project area and tiles.

Conceptual Consistency:

Raw Flightlines, Classified LAS files, Breaklines, and Raster DEMs were tested by Photo Science for vertical 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 whenever possible. Unfortunately, during the LiDAR acquisition there were a few mountain

peaks where the clouds never lifted high enough to collect LiDAR.

Lineage

Process Steps

Process Step 1

CC ID: 757930
Description:

Control Process:

Photo Science, Inc. established control points on Tutuila that were used to calibrate the LiDAR to known ground locations to be used in the post processing of the LiDAR data. The points were located on relatively flat terrain on surfaces that generally consisted of grass, gravel, pavement or bare earth and were in well-defined discrete locations.

Raw Flight Line Process:

Applanix software was used in the post processing of the airborne GPS and inertial data that is critical to the positioning and orientation of the sensor during all flights. POSPac MMS provides the smoothed best estimate of trajectory (SBET) that is necessary for Optech's post processor to develop the point cloud from the LiDAR missions. The point cloud is the mathematical three dimensional collection of all returns from all laser pulses as determined from the aerial mission. At this point this data is ready for analysis, classification, and filtering to generate a bare earth surface model in which the above ground features are

removed from the data set. The point cloud was manipulated within the Optech software; GeoCue, TerraScan, and TerraModeler software was used for the automated data classification, manual cleanup, and bare earth generation from this data. Project specific macros were used to classify the ground and to remove the side overlap between parallel flight lines. All data were manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler.

Classified LAS Process:

All ground (ASPRS Class 2) LiDAR data inside of the Lake Pond and Double Line Drain hydro flattening breaklines were then classified to water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 1 meter was also used around each hydro flattened feature to classify these ground (ASPRS Class 2) points to ignored ground (ASPRS Class 10). All Lake Pond Island and Double Line Drain Island features were checked to ensure that the ground (ASPRS Class 2) were reclassified to the correct classification after the automated classification was completed. A description of each deliverable class can be found below:

Class 1 - Unclassified points; includes non-ground points such as buildings and vegetation.

Class 2 - Ground points

Class 7 - Noise points; includes all high and low noise points that do not represent legitimate features.

Class 9 - Water points

Class 10 - Ignored Ground points; includes all ground points that fall within a 1 meter buffer around any hydro breakline feature.

Classifying these points aids in the hydro flattened DEM creation.

Class 17 - Overlap Unclassified points; Overlap points that represent non-ground features.

Class 18 - Overlap Ground points; Overlap points that represent the ground surface. These points were classified

based on their x,y and z proximity to the Class 2 ground points. No manual cleanup was performed on these points.

All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to class.

Data was then run through additional macros to ensure deliverable classification levels matching the ASPRS LAS Version 1.2 Classification structure. GeoCue functionality was then used to ensure correct LAS Versioning. In-house software was used as a final QA/QC check to provide LAS Analysis of the delivered tiles. QA/QC checks were performed on a per tile level to verify final classification metrics and full LAS header information.

Process Date/Time: 2012-01-01 00:00:00

Process Step 2

CC ID: 757931
Description:

The NOAA Office for Coastal Management (OCM) received the files in ERDAS img format. Files were converted to cloud optimized GeoTiff format using GDAL.

Process Date/Time: 2018-06-13 00:00:00

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2012 NOAA American Samoa Lidar: Islands of Tutuila, Aunu'u, Ofu, Olosega, Ta'u and Rose Atoll

Source point cloud data for these DEMs

Catalog Details

Catalog Item ID: 52876
Metadata Record Created By: Kirk Waters
Metadata Record Created: 2018-06-13 09:40+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2019-07-02 15:17+0000
Metadata Record Published: 2018-06-13
Owner Org: OCM
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2019-06-14