Metadata: Identification_Information: Citation: Citation_Information: Originator: Mr. Patrick Caldwell Publication_Date: Unpublished material Title: Ocean currents measured by shipboard ADCP from global oceans-- the Joint Archive for Shipboard ADCP holdings acquired between December 2007 and December 2008 Online_Linkage: http://ilikai.soest.hawaii.edu/sadcp/ Description: Abstract: Absolute U- and V-component ocean current vectors from Shipboard Acoustic Doppler Current Profilers (SADCP), as both a high frequency sampling (nominally 5 minutes with 8 m depth bins) and an averaged subset (hourly time and 10 m depth means), are provided for the global oceans. The depth range is typically from 20 to 300 m although recent technology has allowed penetration to over 1 km. The high frequency samples along with ancillary parameters are provided in the Common Oceanographic Data Assess System (CODAS) binary format. The standard (averaged) subset is stored in ASCII. This dataset represents the cruises acquired from December 2007 through December 2008 at the Joint Archive for SADCP, a collaboration of NOAA and the E.Firing ADCP Laboratory at the University of Hawaii. The data have been contributed by both US and international organizations. A total of 125 cruises on 13 ships (1.2 gigabytes) are included. Purpose: Provide an archive of absolute ocean current data for global oceans. Supplemental_Information: NOAASupplemental: Entry_ID: Unknown Sensor_Name: ADCP, GPS Source_Name: R/V Discovery R/V David_Starr_Jordan R/V Ka`imikai-O-Kanaloa R/V Kilo_Moana R/V Knorr R/V Laurence_M_Gould R/V Melville R/V Mirai R/V Nathaniel_B._Palmer R/V New_Horizon R/V Ron_Brown R/V Roger_Revelle R/V Thomas_G._Thompson Project_Campaign: Joint Archive for Shipboard ADCP Storage_Medium: CODAS and ASCII Online_size: 1.2 Gbytes Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19931008 Ending_Date: 20080222 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: Annually Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -180.0 East_Bounding_Coordinate: 180.0 North_Bounding_Coordinate: 55.0 South_Bounding_Coordinate: -80.0 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: ocean currents Theme_Keyword: shipboard acoustic doppler current profilers (ADCP) Theme_Keyword: R/V Discovery Theme_Keyword: R/V David_Starr_Jordan Theme_Keyword: R/V Ka`imikai-O-Kanaloa Theme_Keyword: R/V Kilo_Moana Theme_Keyword: R/V Knorr Theme_Keyword: R/V Laurence_M_Gould Theme_Keyword: R/V Melville Theme_Keyword: R/V Mirai Theme_Keyword: R/V Nathaniel_B._Palmer Theme_Keyword: R/V New_Horizon Theme_Keyword: R/V Ron_Brown Theme_Keyword: R/V Roger_Revelle Theme_Keyword: R/V Thomas_G._Thompson Place: Place_Keyword_Thesaurus: None Place_Keyword: global oceans Place_Keyword: Pacific Place_Keyword: Atlantic Place_Keyword: Indian Place_Keyword: Southern Ocean Stratum: Stratum_Keyword_Thesaurus: None Stratum_Keyword: upper ocean (< 1500 m) Access_Constraints: None Use_Constraints: data set credit required Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Mr. Patrick Caldwell Contact_Organization: NOAA/NESDIS/NODC/NCDDC Hawaii Liaison Office Contact_Address: Address_Type: mailing and physical Address: 1000 Pope Rd. MSB 316 City: Honolulu State_or_Province: HI Postal_Code: 96822 Country: USA Contact_Voice_Telephone: 808-956-4105 Contact_Facsimile_Telephone: 808-956-4105 Contact_Electronic_Mail_Address: patrick.caldwell@noaa.gov Hours_of_Service: 7 AM to 4 PM Contact_Instructions: email best option Data_Set_Credit: NOAA/NESDIS/NODC/NCDDC Pacific Islands Liaison Office, Joint Archive for Shipboard ADCP(NOAA/Univ. of Hawaii) provided the service of centralizing the data. See the cruise summary file for each individual cruise to give additional credit to the data collectors, projects, and institutes. Native_Data_Set_Environment: ASCII and CODAS (binary) Data_Quality_Information: Logical_Consistency_Report: complete Completeness_Report: Cruises acquired prior to December 2007 were submitted to the NODC in previous years. Lineage: Process_Step: Process_Description: This annual submission includes three cruises that replace existing cruises in the NODC database. The JASADCP IDs for these cruises are 00409, 00410, and 00411. The original data were sent to NODC in 2001, Accession number unconfirmed. The data were replaced in 2008 after updated calibration and editing were received. This new submission includes 122 new cruises which were received at the JASADCP after the most recent submission to NODC (NODC Accession 0036863, sent to NODC in November 2007). Data are from 13 unique vessels. Data were provided from 3 countries (US, UK, and Japan). Some cruises have more than one ADCP. If the depth penetration and resolution characterists differ, then a unique JASADCP ID (sometimes refered to as an SAC ID) is assigned to each data source. Thus, there could be more than one ADCP set for a single cruise. Such occurrences are documented in the cruise summary file. Shipboard ADCP Data Collection Methodology. The hull-mounted ADCP estimates horizontal and vertical velocity as a function of depth by using the Doppler effect to measure the radial relative velocity between the instrument and scatterers in the ocean. Three acoustic beams in different directions are the minimal requirement for measuring the three velocity components. A fourth beam adds redundancy and an error estimate. The ADCP transmits a ping from each transducer element roughly once per second. The echo arrives back at the instrument over an extended period, with echos from shallow depths arriving sooner than ones from greater ranges. Profiles are produced by range-gating the echo signal, which means the echo is broken into successive segments called depth bins which correspond to successively deeper depth ranges. The operator configures the length of each depth bin and the transmit pulse, which determines the degree of averaging in the vertical, depending on whether one is interested more in vertical resolution or profile penetration. The noisy velocity estimates from each ping are vector-averaged into 1- to 10-minute ensembles. The relative velocities are rotated from the transducer's to the earth's reference frame using the ship's gyrocompass. Finally, relative velocities and various ancillary parameters are stored on the ship using a data acquisition system (DAS) which also optionally records navigation information, such as provided by the GPS. Specifics of the instrument capabilities and configuration options are well documented (RDI, 1989).RD Instruments, 1989. Acoustic Doppler Current Profilers Principles of Operation: A Practical Primer. Available from RD Instruments, 9855 Businesspark Av., San Diego, CA 92131Routine processing, quality control, and calibration are performed at the host institute. Standard checks include detecting and correcting time errors, applying transducer-level temperatures and salinities to obtain a better estimate of the sound speed for the velocity calculation, editing out bad bins or profiles that have been contaminated by interference with the bottom or some other physical object such as a hydro wire, and verifying the quality of the gyrocompass and the navigation data. The final gyrocompass estimates of ship heading and the navigation information are the primary sources for calibrating the ADCP's relative current velocities. Typically, one is correcting for a "angle" error due to misalignment of the transducer relative to the ship's hull and an "amplitude" component related mostly to minor imperfections of the transducer geometry. Relative current velocity errors caused by these components are orthogonal; the angle errors lead to uncertainties of the athwartships velocity component while the amplitude error introduces uncertainties along the ship track.The navigation calculation is performed once calibration is complete. Absolute currents over a fixed depth range (reference layer) are obtained by subtracting the average of the ship velocity relative to a reference layer (i.e. ADCP velocities) from the absolute ship velocity over the ground (from navigation, i.e., GPS). The raw absolute current velocities relative to the reference layer are smoothed to reduce the effects of noise in the position fixes and combined with the navigation data to obtain the best estimates of ship positions and velocities, which are stored into the data base. Thus, absolute currents at any depth can be determined from the final ship navigation data and the relative ADCP measurements.What is the data quality?For the shipboard ADCP, the processing and quality assessment have been left to the data originator. For the majority of cruises, the data were processed and documented using the CODAS software distributed by the E.Firing Laboratory at the University of Hawaii. Profiles were screened objectively and subjectively, but personnel and methods changed over time. For data contributed by other institutions using non-CODAS software, the data originators were instructed to contribute only processed and documented data sets. Once these data arrive at the JASADCP, a general review of the data is undertaken, but no specific flagging system is added.The heterogeneity of operational conditions--ship speed, sea state, and distribution of acoustic scatterers--makes it difficult to quantify the data quality for a given cruise. Conditions and data quality can vary greatly during a single cruise. Data quality also varies with depth in each profile, with problems being most common in the top bin and towards the end of the profiling range. The data user is therefore referred to the documentation file accompanying each cruise for notes about adverse conditions and corresponding data quality problems at specific times during a cruise. Additional quality information is available in the high-resolution data set stored in Common Oceanographic Data Access System (CODAS) blockfiles. For each depth of each profile, a flag byte shows the results of editing, partly by hand and partly mechanized. A "percent good" byte records the percentage of single ping samples accepted by the ADCP for averaging at each depth bin in each ensemble-average profile (typically 5 minutes, the shortest interval for which data are saved). Both the flag byte and "percent good" (> 30%) are used when extracting data for the ASCII standard subset. For more insight and control, users may wish to extract data from the CODAS directly, using their own criteria. Caldwell, P., 1995. NODC archives shipboard ADCP data. Earth System Monitor, Vol. 5, No. 3, pp. 4-8. Caldwell, P., 1996. Advances from the shipboard ADCP Archive Center. Earth System Monitor, Vol. 6, No. 3, p. 14. Firing, E., 1992. Notes from acoustic Doppler Current Profiler Workshop at the National Oceanographic Data Center, May 14-15, 1992. "unpublished manuscript." Hawaii NODC Liaison Office, Dept. of Oceanography, 1000 Pope Rd.,Univ. of Hawaii, Honolulu, HI 96822 Process_Date: Unknown Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Mr. Patrick C. Caldwell Contact_Organization: NOAA/NESDIS/NODC/NCDDC Contact_Position: Hawaii/US Pacific Liaison, Joint Archive for Shipboard ADCP manager Contact_Address: Address_Type: mailing Address: 1000 Pope Road, MSB 316 Address: Dept. of Oceanography Address: University of Hawaii at Manoa City: Honolulu State_or_Province: Hawaii Postal_Code: 96822 Country: USA Contact_Voice_Telephone: (808)-956-4105 Contact_Facsimile_Telephone: (808) 956-2352 Contact_Electronic_Mail_Address: caldwell@hawaii.edu Contact_Electronic_Mail_Address: patrick.caldwell@noaa.gov Hours_of_Service: 8 AM to 5 PM weekdays Contact_Instructions: check services@nodc.noaa.gov if not available Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Joint Archive for Shipboard ADCP: Annual Submission to NODC December 29, 2008 This annual submission includes three cruises that replace cruises in the existing NODC database. The JASADCP IDs for these cruises are 00409, 00410, and 00411. The original data were sent to NODC in 2001, Accession number unconfirmed. The data were replaced in 2008 after updated calibration and editing were received. This new submission includes 122 new cruises which were received at the JASADCP after the most recent submission to NODC (NODC Accession 0036863, sent to NODC in November 2007). Data are from 13 unique vessels. Data were provided from 3 countries (US, UK, and Japan). Some cruises have more than one ADCP. If the depth penetration and resolution characterists differ, then a unique JASADCP ID (sometimes refered to as an SAC ID) is assigned to each data source. Thus, there could be more than one ADCP set for a single cruise. Such occurrences are documented in the cruise summary file. Data organized in directories as: /SAC_ID (unique cruise) Information regarding each SAC_ID can be seen in file: cruise_list_for_Dec2008_NODC_xfer.txt Total size on this tape: 1.2 gigabytes Files on this directory: ship_list.txt: ship names, subdirectory abbreviations, ship codes cruise_list_for_Dec2008_NODC_xfer.txt: Identification Numbers (SAC IDs), year of cruise, ship name, cruise name given by PI format_and_method.txt: format description for NODC standard subset and notes on data reduction For each cruise (unique directory): sssss.sub "standard subset (hourly and 10 m depth intervals for U,V, transducer temp, and ship U, ship V, for sac_id=sssss, ie. 00123.sub" sssss.bft "cruise summary, or block footer as we call it" sssssnnn.blk "CODAS block nnn for cruise sssss" sssssdir.blk "CODAS block directory for cruise sssss" *some directories contain file mkblkftr.cnt-- ignore it. for SAC ID 01070 (R/V Mirai), there are no *.blk files. The original data files are provided. THE NODC STANDARD SUBSET OF SHIPBOARD ADCP DATA The NODC provides shipboard ADCP data in two formats: 1) a high-resolution set in CODAS binary format consisting of currents and ancillary parameters at the sampling interval with which the data were recorded and processed and 2) an ASCII standard subset of absolute currents at hourly and 10 m intervals. If absolute currents are not available due to lack of navigation, then relative currents are provided. If NODC receives data sets that are not of high resolution, then the standard subset may be of a slightly different timing sequence than hourly and the depth spacing may be other than 10 m. For instance, if a data set is received as gridded averages in space, then a nominal time will be assigned. Similarly, if a data set is received with 8 m depth spacing, then this interval is used in the subset. The standard subset includes the hourly means and standard deviations of ship velocity components and the transducer temperature, when available. A description of the methodology and format of the standard subset is given below. METHODOLOGY The standard subset will consist of absolute currents if the ship navigation was satisfactory. Otherwise the currents will be given relative to the mean over a reference layer, usually 50 to 150 m. In the vertical, each velocity profile is linearly interpolated to a regular grid at integral multiples of 10 m. The shallowest level is the first multiple of 10 m that is greater than or equal to the depth of the first good bin of the recorded data, typically a function of the instrument configuration and the transducer depth. The deepest level is that at which at least 50% of the ensembles over the course of the cruise have a Percent Good greater than 30%. For each depth bin, the Percent Good is the percentage of individual pings in an ensemble with valid data. As noted above, for data sets received at NODC in a reduced form (ie., not high-resolution), the original depth interval is maintained. In time, averages are calculated for one-hour intervals centered on the hour. The time column in the ASCII subset gives the mean of the times of the ensembles that fall into the interval. Hence the mean may be slightly off the integral hour, even when ensembles are evenly available over the entire hour. The mean time may be even less centered in the case where data are only partially available over the interval because instrument recording was turned off (e.g., at port calls). In the case where data are totally unavailable over the entire interval so no mean time can be calculated, a "placeholder" entry is made and assigned a time value exactly at the middle of the interval, i.e., on the hour, followed by bad value flags for the longitude, latitude and velocity fields. It is left to the user to manipulate the time column if a truly even time grid is desired. At each level, a bad value flag is given if less than 50% of the ensembles in the hour have valid data. Bad value flags (99999) for velocity components also occur at depth layers where less than 50% of the ensembles in the interval contribute to the average because of low percent good and other editing criteria, or in the case of absolute currents, occur over the entire depth range because ship velocity was not available as a reference. The transducer temperature is provided as a mean and standard deviation over the hour. The ship velocity is provided as means and standard deviations of the components over the hour and is derived from the final absolute ship velocities of each ensemble as stored in the CODAS high-density database. The ship velocity information allows one to see at a glance if the ship was on-station, underway, or both over the hour. FORMAT DESCRIPTION ====> HEADER RECORD sac_id=xxxxx yr_base=yyyy start_lev=ddm num_lev=ddd type < > denotes optional e.g. sac_id=00001 yr_base=1993 start_lev= 20m num_lev= 45 absolute depth_int= 8m where sac_id is a unique identifier for the cruise (NODC bookkeeping) yr_base is the year inwhich the cruise begins start_lev is starting level (meters) num_lev is the number of levels type means either "absolute" or "relative" currents depth_int is the depth interval or spacing between levels and is left blank if equal to 10 m (default) If a data set is received at NODC in a reduced form (ie., not high- resolution), then a comment will be appended to the header to define the timing scheme and the depth spacing if it is other than hourly or 10 m. A complete documentation file which describes the cruise, instrumentation, processing, and other pertinent comments for the given cruise will be available separately. ====> DATA RECORD The format is designed for ease of application; therefore, the date-time and positions are provided in decimal form as a single field. Each data record will be fixed length although the length may vary from cruise to cruise due to differences in the number of depth bins. The order of each record is as follows: With a template such as: ddd.fffff dddd.dddd ddd.dddd tt.t tt.tt suu.u su.uu svv.v sv.vv uuuuu vvvvv .. e.g. 350.00002 157.9365 6.9120 28.9 0.01 -4.6 0.11 -3.4 0.09 419 177 .. field template comment ddd.fffff: decimal day; e.g. 0.50000 is 1200 UTC on January 1 of the year given by yr_base; always present dddd.dddd ddd.dddd: longitude and latitude decimal degrees; lon positive east, lat positive north; missing flag= 1E38; e.g. -145.1667 is 145 deg 10' W tt.t tt.tt transducer temperature mean and standard deviation (deg C); missing = 1E38 suu.u su.uu svv.v sv.vv absolute ship velocity components means and standard deviations in m/sec; missing = 1E38 uuuuu vvvvv current components in mm/sec; bad or missing = 99999; e.g. 121 is 12.1 cm/s Total volume (bytes): 1,006,531,261 Total cruises: 78 Total ships: 12 For complete ship information, see ship_list.txt JASADCP SACID YEAR SHIP_CODE CRUISE SACID YEAR SHIP_CODE CRUISE 00409 1994 dsjordan.usa dj9401 00410 1993 nhorizon.usa nh9310 00411 1994 nhorizon.usa nh9410 01070 2005 mirai.jpn 49MR0502_1 01071 2004 discovry.uk di277 01072 2004 discovry.uk di278 01073 2004 discovry.uk di279 01074 2006 nbpalmer.usa np0701nb150 01075 2007 nbpalmer.usa np0702nb150 01076 2007 nbpalmer.usa np0703nb150 01077 2007 nbpalmer.usa np0709nb150 01078 2007 nbpalmer.usa np0711nb150 01079 2007 ronbrown.usa RB0711bb75 01080 2007 ronbrown.usa RB0711nb75 01081 2008 ronbrown.usa RB0801bb75 01082 2008 ronbrown.usa RB0801nb75 01083 2008 knorr.usa knox14rr 01084 2006 melville.usa mvMagellan4 01085 2005 rrevelle.usa ZHNG08RR 01086 2004 thompson.usa TN168-1 01087 2004 lmgould.usa LG0413a_nb150 01088 2004 lmgould.usa LG0413a_bb038 01089 2004 lmgould.usa LG0413a_nb038 01090 2004 lmgould.usa LG0414_nb150 01091 2004 lmgould.usa LG0414_bb038 01092 2004 lmgould.usa LG0414_nb038 01093 2004 lmgould.usa LG0501_nb150 01094 2004 lmgould.usa LG0501_bb038 01095 2004 lmgould.usa LG0501_nb038 01096 2005 lmgould.usa LG0502_nb150 01097 2005 lmgould.usa LG0502_bb038 01098 2005 lmgould.usa LG0502_nb038 01099 2000 dsjordan.usa dj0004 01100 2001 dsjordan.usa dj0101 SHIP_CODE SHIP_NAME COUNTRY NODC_SHIP_CODE YEARS VALID discovry.uk Discovery United_Kingdom 74DI all_years dsjordan.usa David_Starr_Jordan United_States_of_America 31JD all_years kaimkana.usa Ka`imikai-O-Kanaloa United_States_of_America 33KI all_years kilomoan.usa Kilo Moana United_States_of_America 33KB all_years knorr.usa Knorr United_States_of_America 316N all_years lmgould.usa Laurence_M_Gould United_States_of_America 33LG all_years melville.usa Melville United_States_of_America 318M all_years mirai.jpn Mirai Japan 35XX all_years nbpalmer.usa Nathaniel_B._Palmer United_States_of_America 3206 all_years nhorizon.usa New_Horizon United_States_of_America 31NM all_years ronbrown.usa Ron_Brown United_States_of_America 33RO all_years rrevelle.usa Roger_Revelle United_States_of_America 33RR all_years thompson.usa Thomas_G._Thompson United_States_of_America 31TT 1963-1991 3250 1992- Entity_and_Attribute_Detail_Citation: none Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: NOAA/NESDIS/National Oceanographic Data Center Contact_Person: Data Access Group, User Services Team Contact_Address: Address_Type: mailing and physical Address: SSMC-3 Fourth Floor Address: 1315 East West Highway City: Silver Spring State_or_Province: MD Postal_Code: 20910-3282 Country: USA Contact_Voice_Telephone: 301-713-3277 Contact_Facsimile_Telephone: 301-713-3302 Contact_Electronic_Mail_Address: services@nodc.noaa.gov Hours_of_Service: 8am-5pm, Monday through Friday Resource_Description: NODC Accession Number 0036863 Distribution_Liability: NOAA makes no warranty regarding these data,expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA, NESDIS, NODC and NCDDC cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: CODAS and ASCII Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://data.nodc.noaa.gov/accession/xxxxxxx Fees: Prices vary depending on data set, output medium and ordering mechanism. A standard handling charge, with additional costs for special handling, may be added to the basic cost of the data. Ordering_Instructions: Prepayment by check, money order or bank card is required. Orders may be placed via fax, email, regular mail, telephone or via the NNDC Online Store. Metadata_Reference_Information: Metadata_Date: 20081230 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Mr. Patrick C. Caldwell Contact_Organization: NOAA/NESDIS/NODC/NCDDC Contact_Position: Hawaii/US Pacific Liaison Contact_Address: Address_Type: mailing Address: 1000 Pope Road, MSB 316 Address: Dept. of Oceanography Address: University of Hawaii at Manoa City: Honolulu State_or_Province: Hawaii Postal_Code: 96822 Country: USA Contact_Voice_Telephone: (808)-956-4105 Contact_Facsimile_Telephone: (808) 956-2352 Contact_Electronic_Mail_Address: caldwell@hawaii.edu Contact_Electronic_Mail_Address: patrick.caldwell@noaa.gov Hours_of_Service: 8 AM to 5 PM weekdays Contact_Instructions: check services@nodc.noaa.gov if not available Metadata_Standard_Name: FGDC CSDGM Metadata_Standard_Version: FGDC-STD-001-1998