The following is a description of the fields in the comma delimited data file

output by MIDAS.  This file format is suitable for import to most popular data

management systems AND spreadsheets.



(Sampling time data):

TD.SysDate - The system date on the MIDAS PC clock at each polling interval.

             Format: "DD-MM-YYYY"

TD.SysTime - The system time on the MIDAS PC clock at each polling interval.

             Format: "HH:MM:SS".  Note that this time is accurate to within

             5 seconds of the actual sampling time for each parameter.



(Navigation data - current location):

ND.SourceLat - The default latitude being used by the Northstar 800X LORAN/GPS

               for navigation.  This latitude is derived from GPS when it is

               available and from LORAN when it is not.  Currently, the firmwar
e

               in the Northstar does not allow us to determine the source of

               this data item.  Format: "dddxmm.hh' N"

ND.SourceLong - The default longitude being used by the Northstar 800X.  Notes

                as above.  Format: "dddxmm.hh' W"

ND.TD1 - Northstar available slave time differences 1 - 5.  Format "ddddd.d" in

         microseconds.

ND.TD2 -

ND.TD3 -

ND.TD4 -

ND.TD5 -



(Navigation data - validity of LORAN signals):

ND.BlinkStatusTD - Blink status of preferred (those use for lat/long conver-

                   sions) TDs.  Format "x".  x="A" data valid x="V" data invali
d

ND.CycleStatusTD - Cycle status of preferred TDs.  Format as above.

ND.SnrStatusTD - Signal-to-noise ration of preferred TDs.  Format as above.

ND.GDOP - Geographic dilution of precision.  Format: "d.ddd" nautical miles.



(Navigation data - current underway parameters):

ND.TrueCOG - True course over ground, degrees.  Format: "ddd".

ND.MagneticCOG - Magnetic course over ground, degrees.  Format: "ddd".

ND.KnotsSOG - Speed over ground, knots.  Format: "##.#".



(Navigation data - waypoint information):

ND.WayPointETA - Estimated time of arrival at current waypoint.  Format: "hh:mm
"

ND.TimeToWayPt - Estimated time to go until arrival at waypoint. Format: "hh:mm
"

ND.WayPtCrossTrkErrNMiles - Waypoint cross-track error, naut. mi. Format: "##.#
"

ND.WayPtCrossTrkErrDir - Waypoint cross-track error direction. Format: "x" =

                        (R)ight or (L)eft.

ND.WayPtLat - Waypoint location, latitude.  Format as for above latitude.

ND.WayPtLong - Waypoint location, longitude.  Format as for above longitude.

ND.RangeToWayPt - Range to waypoint, naut. mi.  Format: "###.#".

ND.BearingToWayPt - Compass bearing to waypoint, degrees.  Format: "ddd".



(Navigation data - current location, LORAN-specific):

ND.LoranLat - Current latitude, as calculated from LORAN preferred TDs below.

              Format as for above latitudes.

ND.LoranLong - Current longitude, as calculated from preferred TDs below.

               Format as for above longitudes.

ND.PreferredTD1 - LORAN preferred time difference 1.  Format as for above TDs.

ND.PreferredTD2 - LORAN preferred time difference 2.  Format as for above TDs.



(Navigation data - current location, GPS-specific, CURRENTLY NOT AVAILABLE):

   PRINT #1, ","; ND.GPSLat;

   PRINT #1, ","; ND.GPSLong;



(Hydrographic data - from Seabird C-T meter):

HD.WaterTemp - water temperature, degrees Celcius.  Format:  "###.###".

HD.Conduct - water conductivity, Siemens/meter.  Format: "###.###".

HD.Salinity - water salinity, ppt.  Format: "###.###".



(Hydrographic data - from fluorometer(s)):

HD.ChloroFluorVt - In vivo chlorophyll fluorometer output voltage (0-5v

                   full-scale), corrected for photomultiplier and scale

                   settings on instrument.

                   Format:  "##.###"

HD.AuxFluorVt - Auxiliary fluorometer output voltage.  Format as above.

HD.FluorSwitch - Integer value 0-255 which contains encoded fluorometer switch

                 settings.  Format: "###"

                 Fluorometer switches are hooked to binary inputs on the

                 Polycorder.  It combines the eight switch settings and

                 generates a base 10 integer ranging 0 - 255.  The left four

                 bits (high order) represent switches for fluorometer 1 and

                 the right four bits (low order) represent switches for

                 fluorometer 2.  Decoding is done by converting the integer to

                 a hex representation and using the resulting bit mask to

                 determine switch settings.  Segments of BASIC code below

                 illustrate how the switches are decoded and show the scale

                 and photomultiplier for each switch setting.



                 HexSwitches$ = HEX$(RawFluorSwitches%)

                 Fluor1Switches$ = RIGHT$(HexSwitches$, 1)

                 Fluor2Switches$ = LEFT$(HexSwitches$, 1)

                 SELECT CASE Fluor1Switches$

                        CASE "1"

                                scale! = 1

                                photomultiplier% = 1

                        CASE "9"

                                scale! = 3.16

                                photomultiplier% = 1

                        CASE "5"

                                scale! = 10

                                photomultiplier% = 1

                        CASE "3"

                                scale! = 31.6

                                photomultiplier% = 1

                        CASE "0"

                                scale! = 1

                                photomultiplier% = 100

                        CASE "8"

                                scale! = 3.16

                                photomultiplier% = 100

                        CASE "4"

                                scale! = 10

                                photomultiplier% = 100

                        CASE "2"

                                scale! = 31.6

                                photomultiplier% = 100

                        CASE ELSE

                                scale! = 999

                 END SELECT



                 Fluorometer voltage is scaled as follows:  Raw voltage out of

                 the fluorometer is 0-5 Vt.  Multiply scaled voltage by 2 to be

                 in accordance with 1-10 unit range on the fluorometer dial.



                ScaledFluor1Vt! = RawFluor1Vt! / scale! / photomultiplier% *  2



(Hydrographic data - from transmissometer):

HD.LightTrans - Light transmission, percent.  Format: "###.#".



HD.FlowRate - seawater flow rate through system, liters/minute.  Format: "##.#"
.



(Meteorological parameters - Wind parameters, corrected for ship's heading,

   speed over ground, and course over ground.  Wind parameters represent averag
e

   of 0.5 sec interval measurements over 5 second period (n=10) prior to data

   collection by MIDAS (n=10)):

MD.MeanHzntlWndSpd - Mean horizontal wind speed from sensor, meters/second.

   Format: "###.#"

MD.ResultWndSpd - Resultant wind speed from sensor, meters/second.

   Format: "###.#".

MD.CorrectResultWndSpd - Resultant wind speed, meters/second.  Corrected for

   ship's speed over ground, course over ground and heading.  Format: "###.#"

MD.MeanWndDir - Mean wind direction from sensor, degrees.

   Format: "###".

MD.DevWndDir - Wind Deviation direction fron sensor, degrees.

   Format: "ddd.d".

MD.CorrectMeanWndDir - Mean wind direction, degrees.  Corrected for ship's spee
d

   over ground, course over ground and heading. Format: "###".



(Meteorological parameters - other):

MD.AirTemp - Air temperature, degrees Celcius.  Format: "###.#".

MD.BaroPress - Barometric pressure, inches Hg.  Format: "##.##".

MD.SolarIrrad - Incident radiation, Kw/square meter.  Format: "###.##".



Auxiliary fields are provided for users to insert their own instrumentation int
o

the MIDAS sensor system.  This allows automatic integration of their data into

the MIDAS data set.



Auxiliary differential voltages (1 and 2), spare fields for user-specific

  instrumentation.  Instrumentation output in volts.  Format: "###.###":

AD.DiffAuxVt1 -

AD.DiffAuxVt2 -



!!! NOTE THIS !!!  For the present, the output of the flux gate compass is lo-

cated in this field.



AD.SingAuxVt1 - Flux gate compass heading, degrees.  Format: "ddd".



Auxiliary single-ended voltages (2 and 3).  Output in volts.  Format: "###.###"
:

AD.SingAuxVt2 -

AD.SingAuxVt3 -



Auxiliary pulse count fields, raw counts ranging from 0-9999.  Format:  "####":

AD.AuxPulse1 -

AD.AuxPulse2 -



Auxiliary serial data input string, CURRENT NOT AVAILABLE.

AD.SerialA -



Terminator character for current MIDAS sampling interval record, an exclamation

mark:

!




