Photo Science, Inc.
Unpublished Material
State of Conneticut UTM Zone 19 (Hydro Breaklines): LIDAR for the North East – ARRA and LiDAR for the North East Part II. (USGS Contract: G10PC00026, ARRA LIDAR Task Order Numbers) USGS Contract: G10PC00026 Task Order Number: G10PD02143 Task Order Numbers: G10PD01027 (ARRA) and G10PD02143 (non-ARRA)
model
The LiDAR for the North East Project, funded in large part by the American Recovery and Reinvestment Act (ARRA) of 2009, as well as, other funding sources was designed to help stimulate the U.S. economy and provide for more accurate floodplain mapping in the North East representing the start of a regional LiDAR collection program that served as a test case for a national elevation program. Lead by the United States Geological Survey's (USGS) National Geospatial Program Office and the State of Maine's Office of GIS with active collaboration and participation by other federal, state and local agencies resulted in LiDAR acquisition and processing of over 8,000 sq. miles of (LiDAR) data of a coastal zone spanning six North Eastern states, including Maine, New Hampshire, Massachusetts, Connecticut, Rhode Island, and New York. USGS's National Geospatial Technical Operations Center (USGS NGTOC) in Rolla, MO provided project management and quality control oversight for the project which consisted of two Task Orders issued to USGS contractor, GMR Aerial Surveys inc. d/b/a Photo Science (contractor), for task order execution through the use of USGS's Geospatial Products and Services Contract (USGS Contract: G10PC00026). Task Order specifications included state/area specific vertical accuracy, nominal post spacing and tide coordinated acquisition requirements.
Specific to the State of Conneticut UTM Zone 19, LiDAR was collected in the Winter and Spring 2011
at a 2 meter or better nominal post spacing (2m GSD) for approximately 141
square miles of Conneticut UTM Zone 19, while no snow was on the ground and rivers were at or below normal levels.
In order to post process the LiDAR data to meet task order specifications,
Photo Science subcontractor, The James W. Sewall Company, established a total of 4 control
points that were used to calibrate the LIDAR to known ground locations established throughout
the Conneticut UTM Zone 19 project area. Additionally, Sewall established twenty (20) quality control
"blind" check points using survey grade, dual frequency GPS receivers throughout the
Conneticut UTM Zone 19 project area and the contractor supplied the coordinate and elevation
data values for each point to USGS to independently validate theses required vertical
accuracies. These points were not used by the Contractors production team duing any
phase of the project. Conneticut UTM Zone 19 data was developed based on a horizontal projection/datum
of UTM NAD83 (2007), UTM Zone 19, meters and vertical datum of NAVD1988 (GEOID09), meters.
LiDAR data was delivered in RAW flightline swath format, processed to create Classified
LAS 1.2 Files formatted to 205 individual 1500m x 1500m tiles, Hydro Flattening Breaklines
in Esri shape file format, and corresponding 2.0 meter gridded Raster DEM Files tiled to
the same 1500m x 1500m schema. LiDAR Data was originally delivered to USGS for quality
control validation under USGS Delivery Lot 8b. The lineage (metadata), positional, content
(completeness), attribution, logical consistency, and accuracies of all digital elevation
data produced conform to the specifications stipulated in USGS Task Orders G10PD01027 (ARRA)
and G10PD02143 (non-ARRA) and the U.S. Geological Survey National Geospatial Program Base
LiDAR Specification, Version 12.
Hydro Flattened breaklines are used to provide consistent elevations to a bare earth surface model. This
allows the user to create ESRI Raster DEM, Triangular Irregular Networks and fully Classified LiDAR LAS files.
20110422
20110426
20110429
20110430
20110501
20110502
20110506
ground condition
Unknown
-71.9429310
-71.7640541
42.0224230
41.3016907
none
model
LiDAR
Hydro Flattened Breaklines
remote sensing
None
CT
US
None
None. However, 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 it's limitations. Acknowledgement of the U.S. Geological Survey would be
appreciated for products derived from these data.
Photo Science, Inc. flew the LiDAR and processed the data. Northrop Grumman/3001 helped with the acquisition of the LiDAR data.
MicroStation Version 8; TerraScan Version 11; Optech DASHMap 5.1000; TerraModeler Version 11;
GeoCue Version 7.0.34.5; ESRI ArcGIS 10.0; QT Modeler v 7.1.0; ALS Post Processor 2.70 Build #15; Global Mapper 13; Windows XP Operating System
Photo Science, Inc.
Unpublished Material
State of Conneticut UTM Zone 19 (Raster DEM): LIDAR for the North East – ARRA and LiDAR for the North East Part II. (USGS Contract: G10PC00026, ARRA LIDAR Task Order Numbers) USGS Contract: G10PC00026 Task Order Number: G10PD02143 Task Order Numbers: G10PD01027 (ARRA) and G10PD02143 (non-ARRA)
model
Photo Science, Inc.
Unpublished Material
State of Conneticut UTM Zone 19 (Classified LAS): LIDAR for the North East – ARRA and LiDAR for the North East Part II. (USGS Contract: G10PC00026, ARRA LIDAR Task Order Numbers) USGS Contract: G10PC00026 Task Order Number: G10PD02143 Task Order Numbers: G10PD01027 (ARRA) and G10PD02143 (non-ARRA)
model
Photo Science, inc.
Unpublished Material
State of Conneticut UTM Zone 19: LIDAR for the North East – ARRA and LiDAR for the North East Part II. (USGS Contract: G10PC00026, ARRA LIDAR Task Order Numbers) USGS Contract: G10PC00026 Task Order Number: G10PD02143 Task Order Numbers: G10PD01027 (ARRA) and G10PD02143 (non-ARRA)
model
The project area required LiDAR to be collected on 2.0 meter GSD
or better and processed to meet a bare earth vertical accuracy of 15.0 centimeters
RMSEz or better.
Breaklines 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 dataset deliverable. 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.
Datasets contain complete coverage of project area.
Breaklines 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 dataset deliverable. 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.
Photo Science, Inc.
2012
LiDAR
digital data
hard drive
20110422
20110426
20110429
20110430
20110501
20110502
20110506
ground condition
LiDAR
LiDAR points were used to produce the deliverables.
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 was manually reviewed and any remaining artifacts removed
using functionality provided by TerraScan and TerraModeler.
Class 2 LiDAR was used to create a bare earth surface model. The surface model was then used
to heads-up digitize 2D breaklines of inland streams and rivers with a 30 meter nominal width and
Inland Ponds and Lakes of 8,000 sq. meters or greater surface area.
Ocean Shoreline and Ocean Island features were collected at appropriate elevations on an overall review of the surface models
to determine the land water breaklines. These features were used to determine the classification within the Classified LAS files.
These features can be used to represent a flat water surface, but were not run through the same project
quality control procedures as the inland water body features. Elevation differences between ocean shoreline
and ocean islands will be found. This is due in large part to the coastal water elevation changes, found between missions, as well as
flightline to flightline.
Elevation values were assigned to all Inland Ponds and Lakes, Inland Pond and Lake Islands,
Inland Stream and River Islands, Ocean Shoreline and Ocean Islands using TerraModeler functionality.
Elevation values were assigned to all Inland streams and rivers using Photo Science proprietary software.
All ground (ASPRS Class 2) LiDAR data inside of the collected inland 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. These points were moved from ground (ASPRS Class 2) to Ignored Ground (ASPRS Class 10).
All ground (ASPRS Class 2) LiDAR data inside of the collected ocean breaklines were then classified to bare water (USGS Class 14)
using TerraScan macro functionality. A buffer of 1 meter was also used around each hydro flattened
feature. These points were moved from ground (ASPRS Class 2) to Ignored Ground (ASPRS Class 10).
The breakline files were then translated to ESRI Shapefile format using ESRI conversion tools.
LiDAR
2012
LiDAR post-processed data
DEM
Hydro Flattening Breaklines
Universal Transverse Mercator
19
0.99960000
-69.00000000
0.00000000
500000.00000000
0.0
coordinate pair
1.0
1.0
meters
North American Datum of 1983
World Geodetic System 1984
6378137.000000000000000000
298.257223563000030000
Breakline Types
Breakline Types are limited to Double Line Drain, Double Line Drain Island, Lake Pond, Lake Pond Island, Ocean Shoreline, and Ocean Island.
Inland streams and rivers with a 30 meter nominal width and Inland Ponds and Lakes of 8,000 square meters or greater surface area were collected and attributed.
Breakline collection methodology is specified within the contract. Names were consistent throughout the dataset.
B_LINE_TY
Breakline types.
Attribution is consistent throughout the dataset and meets contract specifications.
Double Line Drain
An inland stream or river with a 30 meter nominal width.
Photo Science standard breakline naming
Double Line Drain Island
An island within an inland stream or river of 4,000 square meters or greater surface area.
Photo Science standard breakline naming
Lake Pond
An inland ponds or lakes of 8,000 square meters or greater surface area.
Photo Science standard breakline naming
Lake Pond Island
An island within an inland ponds or lakes of 4,000 square meters or greater surface area.
Photo Science standard breakline naming
Ocean Shoreline
Any ocean shoreline feature including bays, inlets, etc.
Photo Science standard breakline naming
Ocean Island
An island located in the ocean of 4,000 square meters or greater surface area.
Photo Science standard breakline naming
Breakline Shapefiles in Polyline ZM format. Shapefiles have a breakline type attribute.
All deliverables meet specifications in contract.
20120329
Photo Science, Inc.
Michael Shillenn
mailing and physical address
523 Wellington Way, Suite 375
Lexington
KY
40503
USA
859-277-8700
mshillenn@photoscience.com
FGDC Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998