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https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords |
GCMD Keyword Forum Page |
Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 22. Greenbelt,
MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard
Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA).
URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords |
information |
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https://www.afsc.noaa.gov |
Website |
Website for this organization |
information |
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https://www.fisheries.noaa.gov/inport/item/28076 |
Full Metadata Record |
View the complete metadata record on InPort for more information about this dataset. |
information |
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https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/afsc/dmp/pdf/28076.pdf |
NOAA Data Management Plan (DMP) |
NOAA Data Management Plan for this record on InPort. |
information |
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2009-06-03T00:00:00 |
Multibeam bathymetry and backscatter data collection was performed using Kongsberg
SIS data acquisition software. The file naming convention was inherent to SIS and
ensured that individual survey lines had unique names based on time of collection.
SIS software generated ?.all? files which in addition to bathymetry and backscatter,
contained positional and attitude information, both surface and full profile sound
velocity, and vessel offset and alignment calibration values. All raw data files were
stored on the acquisition computer?s hard drive for the duration of the survey. Multibeam
bathymetry data were also logged by QPS QINSy acquisition software for the EM 710.
These files included navigation, attitude, and heading data from the Pos MV as well
as the secondary positioning data from the CNAV The POS M/V was set up to log Pos
Pac data for both PPK and true heave to use in post processing if deemed necessary.
SVP data were acquired with Sippican WinMark 21Sound velocity profiler software as
binary .rdf files and exported in ascii .edf file format. The raw files from XCTD
probes were further edited into a format compatible with TerraSond Ltd. Simple SVP
conversion software. Sound velocity files were then converted to CARIS format with
Simple SVP formatting software. CARIS .svp files were stored in the SVP folder in
the CARIS folder structure. Sound velocity profiles were further converted into .asvp
format for real-time use in Kongsberg SIS acquisition software. Chronological logs
containing information specific to each line were maintained as an independent reference
to aid in data integration and error tracking. Acquisition logs included the line
name, start and end times, ping rate, range and power settings for each sonar, in
each acquisition software. Acquisition logs included any additional comments deemed
significant by the operator.
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2009-06-03T00:00:00 |
Preliminary multibeam data processing was completed aboard the survey vessel. Following
the initial file conversion and backup, predicted tide data were loaded and each line
was merged with the sounding data in CARIS HIPS. Navigation, Heave, Pitch, and Roll
were already applied and accounted for by the Simrad beam steering algorithms, but
were examined for errors in CARIS HIPS. The data were then cleaned using CARIS HIPS
and SIPS subset editor and a multi-resolution BASE Surface was created to verify coverage
and provide quality control feedback to the survey crew.
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2009-06-03T00:00:00 |
Shipboard data handling proceeded as follows: As multibeam data collection was conducted,
Kongsberg SIS Acquisition software split the raw .all files into thirty minute (30
min) segments. Each segment was then organized by Julian day, and placed onto the
network data storage device. The .all files are then converted into CARIS HIPS multibeam
data processing format and then saved into the CARIS directory. Ultimately the project
data reside on a networked attached storage (NAS) device in a directory identifying
the project name, vessel name, and Julian date. All acquisition data (both raw and
processed) resided on a NAS unit with a redundancy level of RAID 5. The NAS unit itself
was independently backed-up twice daily onto an independent mirrored storage device.
The 2 tiered levels of back-ups insured data security and the ability of the system
to resist catastrophic equipment failure.
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2009-06-20T00:00:00 |
After inspecting the navigation and attitude data, the tide corrected data were merged
with the navigation and attitude data. This initial merging step was conducted with
an incomplete vessel configuration file featuring preliminary patch calibration, and
sensor offset values. The merging process converted time-domain data into spatial-domain,
geographically referenced soundings, and enabled the area based data editing process.
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2009-06-20T00:00:00 |
Following the merging process, area-based editing processes in CARIS HIPS Subset Editor
was performed during the office review of survey soundings. During subset editing,
the operator was presented with two and three-dimensional views of the soundings and
a moveable bounding box to restrict the number of soundings being reviewed. Soundings
were viewed from the south (looking north), from the west (looking east) and in plan
view (looking down). These perspectives, as well as controlling the size and position
of the bounding box, allowed the operator to compare lines, view features from different
angles, measure features, query soundings and change sounding status flags. Soundings
were also examined in the three-dimensional window as points, wire frame or a surface
which could be rotated on any plane. Vertical exaggeration was increased as required
to amplify trends or features. Soundings were flagged as accepted, rejected, designated,
outstanding or examined. In the first phase of area editing, processors examined the
entire survey area in CARIS HIPS Subset Editor and rejected outlying soundings unsupported
by data from adjacent survey lines. Simultaneously, the data were scrutinized for
any potential tide and sound velocity issues that would require further investigation.
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2009-06-20T00:00:00 |
TerraSond, Ltd. incorporates a systematic, rigorous approach to the editing and development
of survey data received from the field. This ensures the maintenance of data integrity
throughout the editing process. CARIS HIPS software was used to create a folder structure
organized by project, vessel, and Julian day to store data. Multibeam raw data were
imported into CARIS HIPS using the CARIS conversion wizard module. The wizard was
used to create a directory for each line and separate the ?.all? files into sub-files
which contained individual sensor information. All data entries were time-referenced
using the time associated with the ?.all? file to relate the navigation, azimuth,
heave, pitch, roll and slant range depths sensor files. CARIS HIPS was used for the
majority of the processing and adjustments made during sounding reduction. CARIS HIPS
does not allow raw data manipulation during processing. All raw data is maintained
in the original, unmodified, format to ensure data integrity. TerraSond, Ltd. uses
well defined procedures during the sounding reduction process and all actions are
tracked to ensure that no steps are omitted or performed out of sequence. Survey lines
were initially opened in the HIPS line editor mode by selecting the project, vessel,
day and desired line. Preliminary soundings were tide adjusted using predicted tide
data from the National Water Level Observation Network (NWLON) station at Village
Cove, St. Paul, AK (946- 4212) through June 25th, 2009. No range, amplitude, or zoning
schemes were applied. Refer to Section C. Corrections to Echo Soundings, of this report,
for detailed information concerning final sounding reduction. Attitude data were viewed
in the CARIS Attitude Editor which displayed simultaneous graphical representation
of all attitude data using a common x-axis scaled by time. The Attitude Editor, like
the Navigation Editor, was used to query the data and reject erroneous values. Navigation
data were reviewed using the CARIS Navigation Editor. The review consisted of a visual
inspection of plotted fixes noting any gaps in the data or unusual jumps in vessel
position. Discrepancies were rare and were handled on a case-by-case basis. Unusable
data were rejected with interpolation using a loose Bezier curve. Data were queried
for time, position, delta time, speed, and status and, if necessary, the status of
the data was changed from accepted to rejected.
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2009-06-20T00:00:00 |
The finalized BASE surface exported in CARIS incorporated uncertainty values derived
from Total Propagated Error (TPE). CARIS HIPS TPE calculation assigned a horizontal
and depth error estimate to each sounding. TPE values represent, at a 95% confidence
level, the difference between computed horizontal and vertical sounding positions
and their true position values. CARIS HIPS computed TPE error values by aggregating
individual error sources such as navigation, gyro (heading), heave, pitch, roll, tide,
latency, sensor offsets and individual sonar model characteristics. Stored in the
HIPS Vessel File, these error sources were obtained from manufacturers during the
instrument calibration process, determined during the vessel survey (sensor offsets)
or while running operational tests (patch test, settlement and squat).
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2009-06-20T00:00:00 |
Several finalized values were applied to the data in the final processing steps in
CARIS HIPS. A verified tide file was downloaded and applied to the survey area prior
to the final merge. Additionally, the locations and times of sound velocity profiles
were displayed graphically to ensure that time-appropriate profiles were applied to
the entire survey, each SV cast was additionally inspected for data quality. CARIS
HIPS presented the option to remove the original SV values and use the CARIS SV correction
algorithms. This step was employed during the final merge, ensuring consistent application
of SV files to the entire dataset. Sound Velocity casts were applied based on the
Previous in Time method of CARIS HIPS. Static draft observations were entered in the
vessel configuration file. The measure down value used to calculate this value varied
3cm between the beginning and the end of the survey therefore for simplicity; a single
value was used for static draft based on the initial measure down value. The 3cm maximum
potential error accrued from the application of a single static draft value is well
within the error budget of this survey. Dynamic draft values were calculated and entered
in the HIPS vessel configuration file. CARIS HIPS uses dynamic draft tables based
on vessel speed and not propeller pitch as was the controlled variable on-board the
Mitchell. Average vessel speed was computed for the range of propeller pitches. The
final processing step before TPE calculation and data export was a final merging of
all data. This merge resulted in the final geographical positions of each sounding
relative (horizontally) to the NAD83 ellipsoid, projected in UTM Zone 2N (m) and vertically
to the Mean Lower Low Water level datum established for Village Cove, St. Paul, AK.
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