R/V FAY Navigation and
Geophysical Data Formats

The navigation and geophysical data stored on this CD-ROM comprise data collected and processed in data formats created and implemented by the Woods Hole Oceanographic Institution (WHOI) Digital Data Library (DDL) in the early 1970's. Thus, in the past, these formats as a whole have generally been referred to as the WHOI-DDL formats.

Below is a summarized listing of all the various WHOI-DDL formats. Some of the listed data formats were not utilized in the processing of the R/V FAY data and therefore will not be found on this CD-ROM. Formats such as EASYG and EASYM were replaced with formats AQU1 and AQMAG. However, their description and inclusion here are to provide a complete listing of the WHOI-DDL formats and are therefore listed for historical purposes only.

Click on the format name to see a detailed description of the data format along with a few lines of example data. NOTE there is a ruler line above the example data to help identify the various columns.

The user would most likely be interested in data in the FIXSE, SEAG, CALCM or MBATR () formats. These data formats provide various information in their final processed version.

• AQMAG -- Observed total magnetic value with ship's heading and speed, date, and Greenwich Mean Time (GMT). If two magnetometers were deployed, then the gradient and separation distance between the magnetometers are included.
• AQU1 -- Observed gravity value, ship's velocity components (velocity north and east), date, and GMT. The format may also also include an observed total magnetic field value and/or corrected depth value in meters for the same time.
• CALCM -- Processed magnetic data including observed magnetic values, magnetic anomaly, date, GMT, and latitude and longitude recorded as decimal degrees. South latitude and west longitude are negative.
• EASYD -- Uncorrected depth values in fathoms or meters with date and GMT. Data were digitized by hand (i.e., data was keypunched or entered manually to computer via data terminal).
  

More details on the EASYD format

• EASYG -- Observed gravity, ship's velocity components, and date and GMT. Data were digitzed by hand (i.e. keypunched or entered via data terminal) and may include observed magnetics value.
• EASYM -- Observed total magnetic field, date, and GMT. Data were digitzed by hand (i.e. keypunched or entered via data terminal).
• FIXSE -- A simple data format which contains ship's navigation information and is most frequently used to generate a representative track line for a given cruise. The format contains ship's latitude and longitude position recorded in degrees and decimal minutes with date and GMT. South latitude and west longitude are recorded as negative values. Additional information regarding position fix source and quality are also included.
• MBATR -- Uncorrected depth values in fathoms, date, GMT, and latitude and longitude as decimal degrees. South latitude and west longitude are negative. If Matthews' table corrections (Matthews, 1939) were applied when the data were processed, the data include corrected depth in fathoms and meters. Data were output from program DTOB.
• NAVC7 -- Latitude and longitude with calculated current-velocity data. Data are output from program ATS1 and input to program ATS3 for gravity processing.
• SEAG -- Processed gravity data including the computed free-air gravity anomaly, date, GMT, and ship's position. Ship's coordinate is recorded as latitude and longitude in radians. South latitude and west longitude are negative. Data in this format was output from program ATS3. If processed gravity data in SEAG format were merged with depth information via program MRGDS, data will include depth values and a simple Bouguer anomaly.
  

More details on the SEAG format

• SEDEP -- Uncorrected depths in fathoms, date, and GMT. Data are output from program EZTD. If Matthews' table corrections (Matthews, 1939) were applied, data also includes depth corrections in fathoms and meters.

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