U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), Santa Cruz, CA.
2011
Raynier Pier, Port Angeles Harbor, Washington, Bathymetry (Cruise ID: S-6-10-PS)
raster digital data
U.S. Geological Survey Open-File Report
1226
https://pubs.usgs.gov/of/2011/1226/
Between February 22, 2010 and March 3, 2010 the U.S. Geological Survey, Pacific Coastal and Marine
Science Center mapped the bathymetry and acoustic backscatter of the Elwha River Delta, Strait of Juan de
Fuca, Washington State. In addition to the main survey, 3 small surveys of interest to USGS partners were
conducted on February 26, 2010. The first is the area surrounding the abandoned Rayonier Pier site in Port
Angeles Harbor, the second is a former log-storage facility on the southern side of Ediz Hook near the Port
Angeles Coast Guard station. Both of these smaller surveys were conducted during a weather day where sea
conditions were too rough for surveying outside the harbor breakwaters. In addition, several lines of data were
collected on the outer face of Ediz hook as the vessel transited to and from the Elwha river delta to inspect
failure features along the northen edge of Ediz Hook first observed in 2005 during USGS cruise K-1-05-PS.
The surveys were conducted using the research vessel R/V Parke Snavely outfitted with an interferometric
sidescan sonar for swath mapping and Real-Time Kinematic navigation equipment for accurate shallow water
operations.
Preliminary bathymetry and acoustic backscatter for change detection and environmental remediation.
The URL for USGS field activity S-6-10-PS is <http://walrus.wr.usgs.gov/infobank/s/s610ps/html/s-6-10-ps.meta.html>
The URL for USGS field activity K-1-05-PS is <http://walrus.wr.usgs.gov/infobank/k/k105ps/html/k-1-05-ps.meta.html>
20100226
20100226
ground condition
as needed
-123.41599070482
-123.39375982089
48.122646567556
48.114965764809
ISO 19115 Topic Category
geoscientificinformation
oceans
Geographic Names Information System (GNIS)
USA
State of Washington
Strait of Juan de Fuca
Port Angeles Harbor
Pacific Ocean
If physical samples or materials are available, constraints on their on-site access are described in "WR CMG
Sample Distribution Policy" at URL:
http://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html
Not suitable for navigation.
Read and fully comprehend the metadata prior to data use.
Acknowledge the U.S. Geological Survey (USGS), the Originator, when using the data set as a source. Any
use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the
U.S. Government.
Share data products developed using the source data set with the Originator.
Data should not be used beyond the limits of the source scale.
This information is not intended for navigational purposes.
The data set is NOT a survey document and should not be utilized as such. Some USGS information
accessed through this means may be preliminary in nature and presented without the approval of the Director
of the USGS.
This information is provided with the understanding that it is not guaranteed to be correct or complete and
conclusions drawn from such information are the responsibility of the user.
USGS Pacific Coastal and Marine Science Center
David P Finlayson
Geologist
physical address
U.S. Geological Survey
400 Natural Bridges Drive
Santa Cruz
CA
95060
USA
(831) 427-4757
(831) 427-4748
dfinlayson@usgs.gov
This bathymetric data has not been independently verified for accuracy.
All bathymetric values are derived from the same instruments and processing workflow.
The Rayonier Pier survey area was a secondary target of opportunity. On 26 February 2010 weather
conditions were too rough for surveying outside Port Angeles harbor and so two alternate survey locations
within the harbor instead.
The Rayonier Pier was not ideally situated relative to the GPS basestation to the west and a few lines were
compromised due to loss of RTK lock. Also, time constraints limited the number of passes the boat was able
to make over the study area. Taken together, the weather, the lower-quality navigation and the relatively large
line spacing did result in higher-than-normal artifacts in the dataset including an along-track "rail" along the
nadir of each trackline and on the eastern side of the pier, scalloping artifacts due to uncompensated pitch
and roll---presumably a result of the choppy conditions. In spite of these problems, the data showed
remarkable details of hundreds of sunken logs ( particularly in the backscatter), submerged pipelines and
evidence of dredging alongside of the pier
Uncertainty in the horizontal position of each sounding is a function of the total uncertainty propagated through
each of the following component instruments: 1) base station GPS, 2) vessel GPS, 3) intertial
motion unit (IMU), 4) water sound velocity model, and 5) beam spreading in the water column. Assuming no
systematic errors in the measurement instruments themselves, beam spreading is the dominate source
of positional uncertainty. The 1-degree sonar beam of the SWATHplus-M results in horizontal uncertainty ranging
from 0.10 m at 10 m slant range, to about 0.45 m at 50 m slant range.
After filtering the data to remove obvious outliers, the standard deviation of the remaining sounding elevations
was calculated for each 1 m x 1 m cell (each containing 28 soundings on average) in CARIS. The mean
standard deviation for all cells in the survey is 0.10 m and 95% of the cells in the data set have a
standard deviation of less than 0.35 m.
Sonar Data Collection
The bathymetric surveys were conducted using a 234.5 kHz SEA (Systems Engineering & Assessment Ltd)
SWATHplus-M phase-differencing sidescan sonar. The sonar was pole-mounted on the 34-foot USGS
mapping vessel R/V Parke Snavely, and affixed to a hull brace. Real-time kinematic (RTK) GPS position data
were passed through a CodaOctopus F180 intertial measurement unit (IMU) to the sonar hardware and data
collection software. Sonar heads, GPS antennae, and the IMU were surveyed in place to a common reference
frame with a Geodimeter 640 Total Station. The R/V Snavely was outfitted with three networked workstations
and a navigation computer for use by the captain and survey crew for data collection and initial processing.
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Geodetic Control
Geodetic control for the survey was established using a shore based Global Positioning System (GPS) base
station broadcasting Real Time Kinematic (RTK) corrections to the survey vessel via UHF radio link. The base
station was located at the base of Ediz Hook. The base station was programmed using the WGS84 (G1150)
reference frame with an Epoch of 2010.1548. Average Opus Solution coordinates for the station are:
Reference Frame: WGS84 (G1150)
Epoch: 2010.1548
Latitude: N 48° 08 06.01943
Longitude: W 123° 28 06.90674
Ellipsoid Height: -11.355m
The average values for the derived OPUS solution for MILL are:
Reference Frame: ITRF00 [same as WGS84 (G1150)]
Epoch: 2010.1548
Latitude: N 48° 08 06.01936
Longitude: W 123° 28 06.90685
Ellipsoid Height: -11.351m
The differences to be added to the RTK broadcast locations are:
Latitude: -0.00007
Longitude: +0.00011
Ellipsoid Height: +0.004m
Using UTM coordinates as a comparison:
The base station was programmed using the following coordinates:
Reference Frame: NAD83, UTM zone 10
Epoch: 2002.0000
Northing: 5331411.376m
Easting: 465138.251m
Ellipsoid Height: -11.042m
Orthometric Height: 9.155m (based Geoid09)
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Vessel Position and Attitude
The R/V Snavely was equipped with a CodaOctopus F180 attitude and positioning system for the duration of
the survey. The F180 is running F190 firmware, and receives real-time kinematic (RTK) corrections directly.
The RTK GPS data (2 cm error ellipse) are combined with the inertial motion measurements directly within the
F190 hardware so that high-precision position and attitude corrections are fed in real-time to the sonar
acquisition equipment. The WGS84 (G1150) Epoch 2010.1548 3-dimensional reference frame was used for
all data acquisition.
20100222
Sound Velocity Measurements
Sound velocity measurements were collected continuously with an Applied Micro Systems Micro SV deployed
on the transducer frame for real-time sound velocity adjustments at the transducer-water interface. The Micro
SV is accurate to +/- 0.03 m/s. In addition, sound velocity profiles (SVP) were collected with an Applied Micro
Systems, SvPlus 3472. This instrument provides time-of-flight sound-velocity measurements by using invar rods
with a sound-velocity accuracy of ±0.06 m/s, pressure measured by a semiconductor bridge strain gauge to an
accuracy of 0.15 percent (Full Scale) and temperature measured by thermistor to an accuracy of 0.05 degrees
Celsius (Applied Microsystems Ltd., 2005).
2010022
Sonar Sounding Processing
GPS data and measurements of vessel motion are combined in the F180 hardware to produce a
high-precision vessel attitude packet. This packet is transmitted to the Swath Processor acquisition
software in real-time and combined with instantaneous sound velocity measurements at the transducer
head before each ping. Up to 20 pings per second are transmitted with each ping consisting of 2048 samples
per side (port and starboard). The returned samples are projected to the seafloor using a ray-tracing algorithm
working with the previously measured sound velocity profiles in SEA Swath Processor (version 3.05.18.04). A
series of statistical filters are applied to the raw samples that isolate the seafloor returns from other
uninteresting targets in the water column. Finally, the processed data is stored line-by-line in both raw (.sxr)
and processed (.sxp) trackline files. Processed (.sxp) files were further processed with sxpegn (build 151) by
David Finlayson (USGS) to remove erroneous data from the files and make valid gain-normalized amplitude
data for processing backscatter data.
2010022
Digital Elevation Model Production
The digital elevation model (DEM) produced in this work is solely derived from the bathymetric data collected
by the USGS during field activity S-6-10-PS. CARIS HIPS and SIPS (version 7.0.2 Service Pack 2) was used
to clean and bin the raw bathymetry. Processed .sxp files were imported to CARIS, and field sheets were
created within CARIS to encompass the survey area.
Survey lines were filtered to remove adjacent line data from nadir gaps. A CARIS Swath Angle BASE
(Bathymetric with Associated Statistical Error) surface was created at 1 m resolution and the subset editor
was used to clean artifacts and other unwanted soundings. The binned data were exported as an ASCII table
along with calculations of the bin standard deviation (of all soundings within the 1 m x 1 m cell spacing) and the
sounding density.
Finally, the ASCII data were gridded in Surfer at 1-m resolution using the IDW algorithm with a 3 m search
radius and a smoothing parameter set to 0.25 (the smoothing parameter here accounts for the horizontal
uncertainty in the sounding position). This process filled small gaps in the surface and provided some minor
smoothing through the statistical noise inherent to interferometric bathymetry. This surface was converted to
ESRI ASCII grid format using Surfer's conversion tools.
20110320
raster
grid cell
1660
846
Universal Transverse Mercator
10
0.9996
-123
0.0
500000
0.0
row and column
1.0
1.0
meters
World Geodetic System 1984 (G1150)
WGS 84
6378137
298.257
World Geodetic System 1984 (G1150)
0.01
meters
Attribute values
Altitude
Altitude (elevation) above the WGS84 (G1150) ellipsoid in meters. Values are positive up.
USGS
U.S. Geological Survey, Pacific Coastal and Marine Science Center (PCMSC)
David P Finlayson
mailing and physical address
U.S. Geological Survey
400 Natural Bridges Drive
Santa Cruz
CA
95060-5792
US
831-427-4757
831-427-4748
dfinlayson@usgs.gov
Downloadable Data
This information is not intended for navigational purposes.
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by
the U.S. Government.
Please recognize the U.S. Geological Survey (USGS) as the source of this information. Physical materials
are under controlled on-site access. Some USGS information accessed through this means may be
preliminary in nature and presented without the approval of the Director of the USGS. This information is
provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from
such information are the responsibility of the user.
ESRI ASCII Grid
1.0
The ASCII file consists of header information containing a set of keywords, followed by cell values in row-major
order. The file format is:
>
><NCOLS xxx>
><NROWS xxx>
><XLLCENTER xxx | XLLCORNER xxx>
><YLLCENTER xxx | YLLCORNER xxx>
><CELLSIZE xxx>
>{NODATA_VALUE xxx}
>row 1
>row 2
>.
>.
>.
>row n
>
where xxx is a number, and the keyword nodata_value is optional and defaults to -9999. Row 1 of the data is
at the top of the grid, row 2 is just under row 1 and so on. The nodata_value is the value in the ASCII file to be
assigned to those cells whose true value is unknown. In the grid they will be assigned the keyword NODATA.
Cell values are be delimited by spaces. No carriage returns are necessary at the end of each row in the grid
(although they are included in this case). The number of columns in the header is used to determine when a
new row begins. The number of cell values is equal to the number of rows times the number of columns.
381 MB
https://pubs.usgs.gov/of/2011/1226/
No cost
20110411
Pacific Coastal and Marine Science Center (PCMSC), US Geological Survey
mailing address
U.S. Geological Survey
400 Natural Bridges Drive
Santa Cruz
California
95060
USA
8314274757
dfinlayson@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998