SEAPATH 200 Intertial Navigation System

SEAPATH outputs data in NMEA format using the following sentence formats:

  • 1. $INGGA-Global System Position Fix Data
  • 2. $INHDT-Heading - True data
  • 3. $INVTG-Course over ground and Ground speed data
  • 4. $INZDA-Time and date

    $INGGA, hhmmss.sss, llll.lllll, a, yyyyy.yyyyy, b, t, nn, v.v, x.x, M,,,c.c,rrrr*hh

    $INGGA-Global System Position Fix Data
    Item Definition Value Units
    $INGGA Header $INGGA  
    hhmmss.sss UTC time of position n/a Hours/Minutes/Seconds.decimal.
    Two fixed digits of hours.
    Two fixed digits of minutes.
    Two fixed digits of seconds.
    Three digits for decimal fractions of a second.
    llll.lllll Latitude -90 to +90 DegreeslMinutes.decimal.
    Two fixed digits of degrees
    Two fixed digits of minutes
    Five digits for decimal minutes.
    a N (north) or S (south) N or S
    yyyyy.yyyyy Longitude -180 to +180 Degrees/Minutes.decimal.
    Three fixed digits of degrees.
    Two fixed digits of minutes.
    Five digits for decimal minutes.
    b E (east) or W (west) E or W
    t GPS Quality Indicator 0 = Fix not available or invalid
    1 = CIA standard GPS; fix valid.
    2 = DGS mode; fix valid.
    3 = PPP mode; fix valid.
    4 = RTK fixed
    5 = RTK float
    6 = free inertial
    nn Number of satellites used in fix 0 to 32
    v.v Horizontal dilution of precision  
    x.x Altitude of the IMU above or below the mean sea level. A negative value indicates below sea level. n/a Metres
    M Units of measure = metres M  
    Null Null
    Null Null
    c.c Age of differential corrections in records since last RTCM-104 message. 0 to 99.9 Seconds
    rrr DGPS reference station identity 0000 to 1023  
    *hh Checksum    
    /CR/LF Carriage return and line feed /CR/LF  

    $INHDT, x.x, T*hh

    $INHDT-Heading - True data
    Item Definition Value Units
    $INHDT Header $INHDT  
    x.x True vessel heading in the vessel frame o to 359.99 degrees
    *hh Checksum n/a
    /CR/LF Carriage return and line feed /CR/LF  

    $INVTG, x.x, T,, M, n.n, N, k.k, K*hh

    $INVTG-Course over ground and Ground speed data
    Item Definition Value Units
    $INVTG Header $INVTG  
    x.x True vessel track in the vessel frame 0 to 359.99 degrees
    T True T  
    null Not supported null  
    M   M  
    n.n Speed in the vessel frame n/a Knots
    N Knots N  
    k.k Kilometres K  
    *hh Checksum n/a
    /CR/LF Carriage return and line feed /CR/LF

    $INZDA, hhmmss.ss, DD, MM, YYYY,, *hh

    $INZDA-Time and date
    Item Definition Value Units
    $INZDA Header $INZDA  
    hhmmss.sss UTC time n/a Hours/Minutes/Seconds.decimal.
    2 fixed digits of hours
    2 fixed digits of minutes
    2 fixed digits of seconds
    Three digits for decimal fractions of a second
    DD Day of month 01 to 31
    MM Month of year 01 to 12
    YYYY Year
    Null Null  
    Null Null
    *hh Checksum n/a
    /CR/LF Carriage return and line feed /CR/LF