ERDDAP > info > C16185_075_Line0864_0

Grid DAP Data	Sub- set	Table DAP Data	Make A Graph	W M S	Source Data Files	Title	Sum- mary	FGDC, ISO, Metadata	Back- ground Info	RSS	E mail	Institution	Dataset ID
	set	data	graph		files	Fugro Cruise C16185 Line 0864, 75 kHz VMADCP		F   I   M	background			GCOOS	C16185_075_Line0864_0

The Dataset's Variables and Attributes

Row Type	Variable Name	Attribute Name	Data Type	Value
attribute	NC_GLOBAL	_NCProperties	String	version=2,netcdf=4.7.4,hdf5=1.12.0,
attribute	NC_GLOBAL	acknowledgement	String	Data collection funded by various oil industry operators
attribute	NC_GLOBAL	cdm_data_type	String	TrajectoryProfile
attribute	NC_GLOBAL	cdm_profile_variables	String	time
attribute	NC_GLOBAL	cdm_trajectory_variables	String	trajectory
attribute	NC_GLOBAL	CODAS_processing_note	String	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 -------+----------+--------+----------+-------+
attribute	NC_GLOBAL	CODAS_variables	String	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. ============= =================================================================
attribute	NC_GLOBAL	contributor_name	String	RPS
attribute	NC_GLOBAL	contributor_role	String	editor
attribute	NC_GLOBAL	contributor_role_vocabulary	String	https://vocab.nerc.ac.uk/collection/G04/current/
attribute	NC_GLOBAL	Conventions	String	CF-1.6, ACDD-1.3, IOOS Metadata Profile Version 1.2, COARDS
attribute	NC_GLOBAL	creator_address	String	6100 Hillcroft Avenue
attribute	NC_GLOBAL	creator_city	String	Houston
attribute	NC_GLOBAL	creator_country	String	USA
attribute	NC_GLOBAL	creator_email	String	metoceansupport at fugro.com
attribute	NC_GLOBAL	creator_institution	String	Fugro Inc
attribute	NC_GLOBAL	creator_name	String	Rosemary Smith
attribute	NC_GLOBAL	creator_phone	String	713-369-5600
attribute	NC_GLOBAL	creator_postalcode	String	77081
attribute	NC_GLOBAL	creator_sector	String	industry
attribute	NC_GLOBAL	creator_state	String	Texas
attribute	NC_GLOBAL	creator_type	String	institution
attribute	NC_GLOBAL	creator_url	String	https://www.fugro.com/
attribute	NC_GLOBAL	cruise_id	String	Fugro_wh75
attribute	NC_GLOBAL	date_created	String	21-11-23T11:45:12Z
attribute	NC_GLOBAL	description	String	Shipboard ADCP velocity profiles from Fugro_wh75 using instrument wh75
attribute	NC_GLOBAL	Easternmost_Easting	double	-90.03921944444443
attribute	NC_GLOBAL	featureType	String	TrajectoryProfile
attribute	NC_GLOBAL	geospatial_bounds	String	LINESTRING (-90.0492361111111 27.25197777777778, -90.03921944444443 27.468219444444443)
attribute	NC_GLOBAL	geospatial_bounds_crs	String	EPSG:4326
attribute	NC_GLOBAL	geospatial_bounds_vertical_crs	String	EPSG:5703
attribute	NC_GLOBAL	geospatial_lat_max	double	27.468219444444443
attribute	NC_GLOBAL	geospatial_lat_min	double	27.25197777777778
attribute	NC_GLOBAL	geospatial_lat_units	String	degrees_north
attribute	NC_GLOBAL	geospatial_lon_max	double	-90.03921944444443
attribute	NC_GLOBAL	geospatial_lon_min	double	-90.0492361111111
attribute	NC_GLOBAL	geospatial_lon_units	String	degrees_east
attribute	NC_GLOBAL	geospatial_vertical_max	double	651.5
attribute	NC_GLOBAL	geospatial_vertical_min	double	27.5
attribute	NC_GLOBAL	geospatial_vertical_positive	String	down
attribute	NC_GLOBAL	geospatial_vertical_units	String	m
attribute	NC_GLOBAL	hg_changeset	String	2924:48293b7d29a9
attribute	NC_GLOBAL	history	String	Created: 2019-07-15 17:47:52 UTC
attribute	NC_GLOBAL	id	String	C16185_075_Line0864_0
attribute	NC_GLOBAL	infoUrl	String	ADD ME
attribute	NC_GLOBAL	institution	String	GCOOS
attribute	NC_GLOBAL	instrument	String	In Situ/Laboratory Instruments > Profilers/Sounders > Acoustic Sounders > ADCP > Acoustic Doppler Current Profiler
attribute	NC_GLOBAL	keywords	String	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
attribute	NC_GLOBAL	keywords_vocabulary	String	GCMD Science Keywords
attribute	NC_GLOBAL	license	String	These data may be redistributed and used without restriction.
attribute	NC_GLOBAL	naming_authority	String	edu.tamucc.gulfhub
attribute	NC_GLOBAL	Northernmost_Northing	double	27.468219444444443
attribute	NC_GLOBAL	platform	String	ship
attribute	NC_GLOBAL	platform_vocabulary	String	https://mmisw.org/ont/ioos/platform
attribute	NC_GLOBAL	processing_level	String	QA'ed and checked by Oceanographer
attribute	NC_GLOBAL	program	String	Oil and Gas Loop Current VMADCP Program
attribute	NC_GLOBAL	project	String	O&G LC VMADCP Program
attribute	NC_GLOBAL	publisher_address	String	6300 Ocean Drive, Unit 5869
attribute	NC_GLOBAL	publisher_city	String	Corpus Christi
attribute	NC_GLOBAL	publisher_country	String	USA
attribute	NC_GLOBAL	publisher_email	String	info at gcoos.org
attribute	NC_GLOBAL	publisher_institution	String	Harte Research Institute, Texas A&M University Corpus Christi
attribute	NC_GLOBAL	publisher_name	String	Gulf of Mexico Coastal Ocean Observing System (GCOOS)
attribute	NC_GLOBAL	publisher_phone	String	(361) 825 3454
attribute	NC_GLOBAL	publisher_postalcode	String	78412
attribute	NC_GLOBAL	publisher_state	String	Texas
attribute	NC_GLOBAL	publisher_type	String	group
attribute	NC_GLOBAL	publisher_url	String	https://gcoos.org
attribute	NC_GLOBAL	software	String	pycurrents
attribute	NC_GLOBAL	sonar	String	wh75
attribute	NC_GLOBAL	source	String	Current profiler
attribute	NC_GLOBAL	sourceUrl	String	(local files)
attribute	NC_GLOBAL	Southernmost_Northing	double	27.25197777777778
attribute	NC_GLOBAL	standard_name_vocabulary	String	CF Standard Name Table v67
attribute	NC_GLOBAL	subsetVariables	String	time, longitude, latitude, depth, u, v
attribute	NC_GLOBAL	summary	String	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.
attribute	NC_GLOBAL	time_coverage_duration	String	P0Y0M0DT2H48M49S
attribute	NC_GLOBAL	time_coverage_end	String	2006-04-21T22:53:36Z
attribute	NC_GLOBAL	time_coverage_resolution	String	P0Y0M0DT0H4M59S
attribute	NC_GLOBAL	time_coverage_start	String	2006-04-21T20:04:47Z
attribute	NC_GLOBAL	title	String	Fugro Cruise C16185 Line 0864, 75 kHz VMADCP
attribute	NC_GLOBAL	Westernmost_Easting	double	-90.0492361111111
attribute	NC_GLOBAL	yearbase	int	2006
variable	trajectory		int
attribute	trajectory	_FillValue	int	-9999
attribute	trajectory	actual_range	int	646481735, 646481735
attribute	trajectory	cf_role	String	trajectory_id
attribute	trajectory	ioos_category	String	Identifier
attribute	trajectory	standard_name	String	trajectory_id
variable	time		double
attribute	time	_CoordinateAxisType	String	Time
attribute	time	actual_range	double	1.145649887E9, 1.145660016E9
attribute	time	axis	String	T
attribute	time	C_format	String	%12.5f
attribute	time	cf_role	String	profile_id
attribute	time	ioos_category	String	Time
attribute	time	long_name	String	Time
attribute	time	standard_name	String	time
attribute	time	time_origin	String	01-JAN-1970 00:00:00
attribute	time	units	String	seconds since 1970-01-01T00:00:00Z
variable	longitude		double
attribute	longitude	_CoordinateAxisType	String	Lon
attribute	longitude	_FillValue	double	1.0E38
attribute	longitude	actual_range	double	-90.0492361111111, -90.03921944444443
attribute	longitude	axis	String	X
attribute	longitude	C_format	String	%9.4f
attribute	longitude	ioos_category	String	Location
attribute	longitude	long_name	String	Longitude
attribute	longitude	missing_value	double	1.0E38
attribute	longitude	standard_name	String	longitude
attribute	longitude	units	String	degrees_east
variable	latitude		double
attribute	latitude	_CoordinateAxisType	String	Lat
attribute	latitude	_FillValue	double	1.0E38
attribute	latitude	actual_range	double	27.25197777777778, 27.468219444444443
attribute	latitude	axis	String	Y
attribute	latitude	C_format	String	%9.4f
attribute	latitude	ioos_category	String	Location
attribute	latitude	long_name	String	Latitude
attribute	latitude	missing_value	double	1.0E38
attribute	latitude	standard_name	String	latitude
attribute	latitude	units	String	degrees_north
variable	depth		float
attribute	depth	_CoordinateAxisType	String	Height
attribute	depth	_CoordinateZisPositive	String	down
attribute	depth	_FillValue	float	1.0E38
attribute	depth	actual_range	float	27.5, 651.5
attribute	depth	axis	String	Z
attribute	depth	C_format	String	%8.2f
attribute	depth	coverage_content_type	String	physicalMeasurement
attribute	depth	ioos_category	String	Location
attribute	depth	long_name	String	Depth
attribute	depth	missing_value	float	1.0E38
attribute	depth	positive	String	down
attribute	depth	postitive	String	down
attribute	depth	standard_name	String	depth
attribute	depth	units	String	m
variable	u		float
attribute	u	_FillValue	float	1.0E38
attribute	u	actual_range	float	0.055701643, 0.7106515
attribute	u	C_format	String	%7.2f
attribute	u	coverage_content_type	String	physicalMeasurement
attribute	u	ioos_category	String	Currents
attribute	u	long_name	String	Zonal velocity component
attribute	u	missing_value	float	1.0E38
attribute	u	standard_name	String	eastward_sea_water_velocity
attribute	u	units	String	meter second-1
variable	v		float
attribute	v	_FillValue	float	1.0E38
attribute	v	actual_range	float	-0.27140164, 0.12978745
attribute	v	C_format	String	%7.2f
attribute	v	coverage_content_type	String	physicalMeasurement
attribute	v	ioos_category	String	Currents
attribute	v	long_name	String	Meridional velocity component
attribute	v	missing_value	float	1.0E38
attribute	v	standard_name	String	northward_sea_water_velocity
attribute	v	units	String	meter second-1
variable	amp		short
attribute	amp	_FillValue	short	32767
attribute	amp	actual_range	short	70, 193
attribute	amp	C_format	String	%d
attribute	amp	coverage_content_type	String	physicalMeasurement
attribute	amp	ioos_category	String	Identifier
attribute	amp	long_name	String	Received signal strength
attribute	amp	missing_value	short	32767
variable	pg		byte
attribute	pg	_FillValue	byte	-1
attribute	pg	actual_range	byte	95, 100
attribute	pg	C_format	String	%d
attribute	pg	coverage_content_type	String	qualityInformation
attribute	pg	ioos_category	String	Unknown
attribute	pg	long_name	String	Percent Good
attribute	pg	missing_value	byte	-1
variable	pflag		byte
attribute	pflag	actual_range	byte	0, 0
attribute	pflag	C_format	String	%d
attribute	pflag	coverage_content_type	String	qualityInformation
attribute	pflag	ioos_category	String	Identifier
attribute	pflag	long_name	String	Editing flags
variable	heading		float
attribute	heading	_FillValue	float	1.0E38
attribute	heading	actual_range	float	185.58, 211.02
attribute	heading	C_format	String	%6.1f
attribute	heading	coverage_content_type	String	auxiliaryInformation
attribute	heading	ioos_category	String	Unknown
attribute	heading	long_name	String	Ship heading
attribute	heading	missing_value	float	1.0E38
attribute	heading	units	String	degrees
variable	tr_temp		float
attribute	tr_temp	_FillValue	float	1.0E38
attribute	tr_temp	actual_range	float	25.35, 26.15
attribute	tr_temp	C_format	String	%4.1f
attribute	tr_temp	coverage_content_type	String	auxiliaryInformation
attribute	tr_temp	ioos_category	String	Unknown
attribute	tr_temp	long_name	String	some temperature
attribute	tr_temp	missing_value	float	1.0E38
attribute	tr_temp	units	String	Celsius
variable	num_pings		short
attribute	num_pings	actual_range	short	103, 135
attribute	num_pings	C_format	String	%d
attribute	num_pings	coverage_content_type	String	auxiliaryInformation
attribute	num_pings	ioos_category	String	Identifier
attribute	num_pings	long_name	String	Number of pings averaged per ensemble
variable	uship		float
attribute	uship	_FillValue	float	1.0E38
attribute	uship	actual_range	float	-0.1633485, 0.3387017
attribute	uship	C_format	String	%9.4f
attribute	uship	coverage_content_type	String	physicalMeasurement
attribute	uship	ioos_category	String	Currents
attribute	uship	long_name	String	Ship Velocity U
attribute	uship	missing_value	float	1.0E38
attribute	uship	units	String	meter second-1
variable	vship		float
attribute	vship	_FillValue	float	1.0E38
attribute	vship	actual_range	float	-2.553362, -2.115433
attribute	vship	C_format	String	%9.4f
attribute	vship	coverage_content_type	String	physicalMeasurement
attribute	vship	ioos_category	String	Currents
attribute	vship	long_name	String	Ship Velocity V
attribute	vship	missing_value	float	1.0E38
attribute	vship	units	String	meter second-1

The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.