Brought to you by NOAA NMFS SWFSC ERD
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Metocean: Historical collections
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Brought to you by NOAA NMFS SWFSC ERD |
| Dataset Title: | Fugro Cruise C16314 Line 0101, 75 kHz VMADCP
|
| Institution: | GCOOS (Dataset ID: C16314_075_Line0101_0) |
| Information: | Summary
| License
| FGDC
| ISO 19115
| Metadata
| Background
| Subset
| Files
| Make a graph
|
Attributes {
s {
trajectory {
Int32 _FillValue -9999;
Int32 actual_range 261356923, 261356923;
String cf_role "trajectory_id";
String ioos_category "Identifier";
String standard_name "trajectory_id";
}
time {
String _CoordinateAxisType "Time";
Float64 actual_range 1.191653559e+9, 1.191705244e+9;
String axis "T";
String C_format "%12.5f";
String cf_role "profile_id";
String ioos_category "Time";
String long_name "Time";
String standard_name "time";
String time_origin "01-JAN-1970 00:00:00";
String units "seconds since 1970-01-01T00:00:00Z";
}
longitude {
String _CoordinateAxisType "Lon";
Float64 _FillValue 1.0e+38;
Float64 actual_range -91.598525, -90.11571111111112;
String axis "X";
String C_format "%9.4f";
String ioos_category "Location";
String long_name "Longitude";
Float64 missing_value 1.0e+38;
String standard_name "longitude";
String units "degrees_east";
}
latitude {
String _CoordinateAxisType "Lat";
Float64 _FillValue 1.0e+38;
Float64 actual_range 27.165419444444446, 27.16709722222222;
String axis "Y";
String C_format "%9.4f";
String ioos_category "Location";
String long_name "Latitude";
Float64 missing_value 1.0e+38;
String standard_name "latitude";
String units "degrees_north";
}
depth {
String _CoordinateAxisType "Height";
String _CoordinateZisPositive "down";
Float32 _FillValue 1.0e+38;
Float32 actual_range 16.76, 600.76;
String axis "Z";
String C_format "%8.2f";
String coverage_content_type "physicalMeasurement";
String ioos_category "Location";
String long_name "Depth";
Float32 missing_value 1.0e+38;
String positive "down";
String postitive "down";
String standard_name "depth";
String units "m";
}
u {
Float32 _FillValue 1.0e+38;
Float32 actual_range -1.2038896, 0.08216858;
String C_format "%7.2f";
String coverage_content_type "physicalMeasurement";
String ioos_category "Currents";
String long_name "Zonal velocity component";
Float32 missing_value 1.0e+38;
String standard_name "eastward_sea_water_velocity";
String units "meter second-1";
}
v {
Float32 _FillValue 1.0e+38;
Float32 actual_range -0.9755965, 0.2985001;
String C_format "%7.2f";
String coverage_content_type "physicalMeasurement";
String ioos_category "Currents";
String long_name "Meridional velocity component";
Float32 missing_value 1.0e+38;
String standard_name "northward_sea_water_velocity";
String units "meter second-1";
}
amp {
Int16 _FillValue 32767;
Int16 actual_range 86, 226;
String C_format "%d";
String coverage_content_type "physicalMeasurement";
String ioos_category "Identifier";
String long_name "Received signal strength";
Int16 missing_value 32767;
}
pg {
Byte _FillValue -1;
String _Unsigned "false";
Byte actual_range 0, 100;
String C_format "%d";
String coverage_content_type "qualityInformation";
String ioos_category "Unknown";
String long_name "Percent Good";
Byte missing_value -1;
}
pflag {
String _Unsigned "false";
Byte actual_range 0, 2;
String C_format "%d";
String coverage_content_type "qualityInformation";
String ioos_category "Identifier";
String long_name "Editing flags";
}
heading {
Float32 _FillValue 1.0e+38;
Float32 actual_range 264.26, 276.74;
String C_format "%6.1f";
String coverage_content_type "auxiliaryInformation";
String ioos_category "Unknown";
String long_name "Ship heading";
Float32 missing_value 1.0e+38;
String units "degrees";
}
tr_temp {
Float32 _FillValue 1.0e+38;
Float32 actual_range 28.39, 28.86;
String C_format "%4.1f";
String coverage_content_type "auxiliaryInformation";
String ioos_category "Unknown";
String long_name "some temperature";
Float32 missing_value 1.0e+38;
String units "Celsius";
}
num_pings {
Int16 actual_range 30, 105;
String C_format "%d";
String coverage_content_type "auxiliaryInformation";
String ioos_category "Identifier";
String long_name "Number of pings averaged per ensemble";
}
uship {
Float32 _FillValue 1.0e+38;
Float32 actual_range -2.949249, -2.70946;
String C_format "%9.4f";
String coverage_content_type "physicalMeasurement";
String ioos_category "Currents";
String long_name "Ship Velocity U";
Float32 missing_value 1.0e+38;
String units "meter second-1";
}
vship {
Float32 _FillValue 1.0e+38;
Float32 actual_range -0.06913324, 0.08341002;
String C_format "%9.4f";
String coverage_content_type "physicalMeasurement";
String ioos_category "Currents";
String long_name "Ship Velocity V";
Float32 missing_value 1.0e+38;
String units "meter second-1";
}
}
NC_GLOBAL {
String _NCProperties "version=2,netcdf=4.7.4,hdf5=1.12.0,";
String acknowledgement "Data collection funded by various oil industry operators";
String cdm_data_type "TrajectoryProfile";
String cdm_profile_variables "time";
String cdm_trajectory_variables "trajectory";
String CODAS_processing_note
"
CODAS processing note:
======================
Overview
--------
The CODAS database is a specialized storage format designed for
shipboard ADCP data. \"CODAS processing\" uses this format to hold
averaged shipboard ADCP velocities and other variables, during the
stages of data processing. The CODAS database stores velocity
profiles relative to the ship as east and north components along with
position, ship speed, heading, and other variables. The netCDF *short*
form contains ocean velocities relative to earth, time, position,
transducer temperature, and ship heading; these are designed to be
\"ready for immediate use\". The netCDF *long* form is just a dump of
the entire CODAS database. Some variables are no longer used, and all
have names derived from their original CODAS names, dating back to the
late 1980's.
Post-processing
---------------
CODAS post-processing, i.e. that which occurs after the single-ping
profiles have been vector-averaged and loaded into the CODAS database,
includes editing (using automated algorithms and manual tools),
rotation and scaling of the measured velocities, and application of a
time-varying heading correction. Additional algorithms developed more
recently include translation of the GPS positions to the transducer
location, and averaging of ship's speed over the times of valid pings
when Percent Good is reduced. Such post-processing is needed prior to
submission of \"processed ADCP data\" to JASADCP or other archives.
Full CODAS processing
---------------------
Whenever single-ping data have been recorded, full CODAS processing
provides the best end product.
Full CODAS processing starts with the single-ping velocities in beam
coordinates. Based on the transducer orientation relative to the
hull, the beam velocities are transformed to horizontal, vertical, and
\"error velocity\" components. Using a reliable heading (typically from
the ship's gyro compass), the velocities in ship coordinates are
rotated into earth coordinates.
Pings are grouped into an \"ensemble\" (usually 2-5 minutes duration)
and undergo a suite of automated editing algorithms (removal of
acoustic interference; identification of the bottom; editing based on
thresholds; and specialized editing that targets CTD wire interference
and \"weak, biased profiles\". The ensemble of single-ping velocities
is then averaged using an iterative reference layer averaging scheme.
Each ensemble is approximated as a single function of depth, with a
zero-average over a reference layer plus a reference layer velocity
for each ping. Adding the average of the single-ping reference layer
velocities to the function of depth yields the ensemble-average
velocity profile. These averaged profiles, along with ancillary
measurements, are written to disk, and subsequently loaded into the
CODAS database. Everything after this stage is \"post-processing\".
note (time):
------------
Time is stored in the database using UTC Year, Month, Day, Hour,
Minute, Seconds. Floating point time \"Decimal Day\" is the floating
point interval in days since the start of the year, usually the year
of the first day of the cruise.
note (heading):
---------------
CODAS processing uses heading from a reliable device, and (if
available) uses a time-dependent correction by an accurate heading
device. The reliable heading device is typically a gyro compass (for
example, the Bridge gyro). Accurate heading devices can be POSMV,
Seapath, Phins, Hydrins, MAHRS, or various Ashtech devices; this
varies with the technology of the time. It is always confusing to
keep track of the sign of the heading correction. Headings are written
degrees, positive clockwise. setting up some variables:
X = transducer angle (CONFIG1_heading_bias)
positive clockwise (beam 3 angle relative to ship)
G = Reliable heading (gyrocompass)
A = Accurate heading
dh = G - A = time-dependent heading correction (ANCIL2_watrk_hd_misalign)
Rotation of the measured velocities into the correct coordinate system
amounts to (u+i*v)*(exp(i*theta)) where theta is the sum of the
corrected heading and the transducer angle.
theta = X + (G - dh) = X + G - dh
Watertrack and Bottomtrack calibrations give an indication of the
residual angle offset to apply, for example if mean and median of the
phase are all 0.5 (then R=0.5). Using the \"rotate\" command,
the value of R is added to \"ANCIL2_watrk_hd_misalign\".
new_dh = dh + R
Therefore the total angle used in rotation is
new_theta = X + G - dh_new
= X + G - (dh + R)
= (X - R) + (G - dh)
The new estimate of the transducer angle is: X - R
ANCIL2_watrk_hd_misalign contains: dh + R
====================================================
Profile flags
-------------
Profile editing flags are provided for each depth cell:
binary decimal below Percent
value value bottom Good bin
-------+----------+--------+----------+-------+
000 0
001 1 bad
010 2 bad
011 3 bad bad
100 4 bad
101 5 bad bad
110 6 bad bad
111 7 bad bad bad
-------+----------+--------+----------+-------+
";
String CODAS_variables
"
Variables in this CODAS short-form Netcdf file are intended for most end-user
scientific analysis and display purposes. For additional information see
the CODAS_processing_note global attribute and the attributes of each
of the variables.
============= =================================================================
time Time at the end of the ensemble, days from start of year.
lon, lat Longitude, Latitude from GPS at the end of the ensemble.
u,v Ocean zonal and meridional velocity component profiles.
uship, vship Zonal and meridional velocity components of the ship.
heading Mean ship heading during the ensemble.
depth Bin centers in nominal meters (no sound speed profile correction).
tr_temp ADCP transducer temperature.
pg Percent Good pings for u, v averaging after editing.
pflag Profile Flags based on editing, used to mask u, v.
amp Received signal strength in ADCP-specific units; no correction
for spreading or attenuation.
============= =================================================================
";
String contributor_name "RPS";
String contributor_role "editor";
String contributor_role_vocabulary "https://vocab.nerc.ac.uk/collection/G04/current/";
String Conventions "CF-1.6, ACDD-1.3, IOOS Metadata Profile Version 1.2, COARDS";
String creator_address "6100 Hillcroft Avenue";
String creator_city "Houston";
String creator_country "USA";
String creator_email "metoceansupport@fugro.com";
String creator_institution "Fugro Inc";
String creator_name "Rosemary Smith";
String creator_phone "713-369-5600";
String creator_postalcode "77081";
String creator_sector "industry";
String creator_state "Texas";
String creator_type "institution";
String creator_url "https://www.fugro.com/";
String cruise_id "Fugro_C16314_075_Line0101_0";
String date_created "21-11-23T11:43:57Z";
String description "Shipboard ADCP velocity profiles from Fugro_C16314_075_Line0101_0 using instrument wh75";
Float64 Easternmost_Easting -90.11571111111112;
String featureType "TrajectoryProfile";
String geospatial_bounds "LINESTRING (-91.598525 27.165419444444446, -90.11571111111112 27.16709722222222)";
String geospatial_bounds_crs "EPSG:4326";
String geospatial_bounds_vertical_crs "EPSG:5703";
Float64 geospatial_lat_max 27.16709722222222;
Float64 geospatial_lat_min 27.165419444444446;
String geospatial_lat_units "degrees_north";
Float64 geospatial_lon_max -90.11571111111112;
Float64 geospatial_lon_min -91.598525;
String geospatial_lon_units "degrees_east";
Float64 geospatial_vertical_max 600.76;
Float64 geospatial_vertical_min 16.76;
String geospatial_vertical_positive "down";
String geospatial_vertical_units "m";
String hg_changeset "2955:483f3262b192";
String history
"Created: 2019-07-31 14:51:55 UTC
2024-05-05T12:57:34Z (local files)
2024-05-05T12:57:34Z https://gcoos5.geos.tamu.edu/erddap/tabledap/C16314_075_Line0101_0.html";
String id "C16314_075_Line0101_0";
String infoUrl "ADD ME";
String institution "GCOOS";
String instrument "In Situ/Laboratory Instruments > Profilers/Sounders > Acoustic Sounders > ADCP > Acoustic Doppler Current Profiler";
String keywords "acoustic, adcp, bins, bsee, circulation, coastal, crs, current, currents, data, depth, dir, direction, direction_of_sea_water_velocity, distance, doppler, drilling, Earth Science > Oceans > Ocean Circulation > Ocean Currents, Earth Science > Oceans > Ocean Temperature > Water Temperature, east, eastward, eastward_sea_water_velocity, gcoos, gulf, identifier, instrument, kika, latitude, longitude, mexico, north, northward, northward_sea_water_velocity, observing, ocean, oceans, platform, platform/ocean, profile, profile_id, profiler, sample, sea, sea_water_speed, sea_water_temperature, seawater, series, speed, stations, stations/drilling, surface, system, temperature, time, time series, towards, upward, upward_sea_water_velocity, velocity, vert, water";
String keywords_vocabulary "GCMD Science Keywords";
String license "These data may be redistributed and used without restriction.";
String naming_authority "edu.tamucc.gulfhub";
Float64 Northernmost_Northing 27.16709722222222;
String platform "ship";
String platform_vocabulary "https://mmisw.org/ont/ioos/platform";
String processing_level "QA'ed and checked by Oceanographer";
String program "Oil and Gas Loop Current VMADCP Program";
String project "O&G LC VMADCP Program";
String publisher_address "6300 Ocean Drive, Unit 5869";
String publisher_city "Corpus Christi";
String publisher_country "USA";
String publisher_email "info@gcoos.org";
String publisher_institution "Harte Research Institute, Texas A&M University Corpus Christi";
String publisher_name "Gulf of Mexico Coastal Ocean Observing System (GCOOS)";
String publisher_phone "(361) 825 3454";
String publisher_postalcode "78412";
String publisher_state "Texas";
String publisher_type "group";
String publisher_url "https://gcoos.org";
String software "pycurrents";
String sonar "wh75";
String source "Current profiler";
String sourceUrl "(local files)";
Float64 Southernmost_Northing 27.165419444444446;
String standard_name_vocabulary "CF Standard Name Table v67";
String subsetVariables "time, longitude, latitude, depth, u, v";
String summary "Program of vessel mount ADCP measurements comprising a combination of 300kHz and 75kHz ADCP data collected in the vicinity of the Loop Current and drilling blocks between 2004 and 2007.";
String time_coverage_duration "P0Y0M0DT14H21M25S";
String time_coverage_end "2007-10-06T21:14:04Z";
String time_coverage_resolution "P0Y0M0DT0H4M59S";
String time_coverage_start "2007-10-06T06:52:39Z";
String title "Fugro Cruise C16314 Line 0101, 75 kHz VMADCP";
Float64 Westernmost_Easting -91.598525;
Int32 yearbase 2007;
}
}
Data Access Protocol (DAP) and its
selection constraints.
The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.
Tabledap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/pmelTaoDySst.htmlTable?longitude,latitude,time,station,wmo_platform_code,T_25&time>=2015-05-23T12:00:00Z&time<=2015-05-31T12:00:00Z
Thus, the query is often a comma-separated list of desired variable names,
followed by a collection of
constraints (e.g., variable<value),
each preceded by '&' (which is interpreted as "AND").
For details, see the tabledap Documentation.