NMEA

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NMEA
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NMEA 0813

• protokol za komunikaciju izmedu elektronskih
  uredaja specijalne namene
• ehosonder, sonar, anemometar(brzina vetra i
  smer), irokompas, autopilot, GPS
• National Marine Electronic Association
• koristi ASCII za definisanje recenice koje se
  transportuje od predajnika do prijemnika u
  vremenu
• Koricenjem multipleksera vie senzora moe
  emitovati ka jednom ili vie prijemnika

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Direktna integracija
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Indirektna integracija
gps
sonar
SQL
gpssonar
SELECT gps.Name, gps.y, gps.x, gps.H,
sonar.Dubina, H-Dubina AS KotaDna FROM gps
INNER JOIN sonar ON gps.Date/Time
sonar.Date/Time
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ISO-OSI standardni model

• Aplikacioni sloj (parsiranje podataka)
• Transportni i mreni sloj (ASCII)
• Sloj veze (Baud rate4800, Data bits 8, Parity
  None, Stop bits1)
• Fizicki sloj (serijski port RS232)

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Aplikacioni sloj

• Svaka poruka tj. recenica pocinje sa
• Sledecih 5 karaktera predstavlja tip poruke
• reci su odvojene zarezom
• kraj recenice je na znaku
• iza ide provera parnosti
• ltCRgtltLFgt oznacava kraj poruke

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Tipovi poruka kao NMEA izlaz za GPS
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Global Positioning System Fix Data (GGA)

• GPGGA,lt1gt,lt2gt,lt3gt,lt4gt,lt5gt,lt6gt,lt7gt,lt8gt,lt9gt,M,lt11gt,
  lt12gt,lt13gtltCRgtltLFgt
•  
• UTC time of position fix, hhmmss.sss format
• Latitude, ddmm.mmmm format.
• Latitude hemisphere, N or S.
• Longitude, dddmm.mmmm format.
• Longitude hemisphere, E or W.
• Position Fix Indicator,
• 0 fix not available, or invalid.
• 1 GPS SPS Mode, fix valid.
• 2 Differential GPS, SPS Mode, fix valid.
• 3 GPS PPS Mode, fix valid.
• 7. Number of sate1lites in use, 00 to 12.
• 8. Horizontal Dilution of Precision, 0.5 to 99.9.
• 9. MSL Altitude, -9999.9 to 99999.9 meters.
• 10. Geoidal height, -999.9 to 9999.9 meters.
• 11. Differential GPS (RTCM SC-104) data age,
  number of seconds since last valid RTCM
  transmission (nu1l if non-DGPS).
• 12. Differential Reference Station ID, 0000 to
  1023. (null if non-DGPS)
• 13. Checksum.

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Geographic Position with Latitude/Longitude

• GPGLL,lt1gt,lt2gt,lt3gt,lt4gt,lt5gt,lt6gt,lt7gtltCRgtltLFgt
• Latitude, ddmm.mmmm format.
• Latitude hemisphere, N or S.
• Longitude, dddmT1.mmmm format.
• Longitude hemisphere, E or W.
• UTC time of position fix, hhmmss format.
• Status, A data valid or V data not valid.
• Checksum.

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GNSS DOP and Active Satellites (GSA)

• GPGSA,lt1gt,lt2gt,lt3gt,lt3gt,,,,,lt3gt,lt3gt,lt3gt,lt4gt,lt5gt,lt6gt
  ,lt7gtltCRgtltLFgt
• Mode 1, M manual, A automatic.
• Mode 2, Fix type, 1 not available, 2 2D, 3
  3D.
• PRN number, 01 to 32, of satellite used in
  solution, up to 12 transmitted.
• PDOP-Position dilu1ion of precision, 0.5 to 99.9.
• HDOP-Horizontal dilution of precision, 0.5 to
  99.9.
• VDOP-Vertical di1ution of precision, 0.5 to 99.9.
• Checksum.

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GNSS Satellites in View (GSV)

• GPGSV,lt1gt,lt2gt,lt3gt,lt4gt,lt5gt,lt6gt,lt7gt,lt4gt,lt5gt,lt6gt,lt7
  gt,lt8gtltCRgtltLFgt
•  
• Total number of GSV sentences to be transmitted,
  03.
• Number of message, 03.
• Total number of satellites in view, 00 to 12.
• Satellite PRN number, 01 to 32.
• Satellite elevation, 00 to 90 degrees.
• Satellite azimuth, 000 to 359 degrees, true.
• Signal to noise ratio (C/No) 00 to 99 dB, null
  when not tracking.
• Checksum.
• NOTE Items lt4gt,lt5gt,lt6gt and lt7gt repeat for each
  satellite in view to a maximum of four (4)
  satellites per sentence.  Additiona1 satellites
  in view information must be sent in subsequent
  sentences. These fields will be null if unused.

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Recommended Minimum Specific GNSS Data (RMC)

• GPRMC,lt1gt,lt2gt,lt3gt,lt4gt,lt5gt,lt6gt,lt7gt,lt8gt,lt9gt,lt10gt,lt1
  1gt, 12gt,ltCRgtltLFgt
• UTC time of position fix, hhmmss.sss format.
• Status, A data valid, V data not valid.
• Latitude, ddmm.mmmm format.
• Latitude hemisphere, N or S.
• Longitude, dddmmm.mmmm format.
• Longitude hemisphere, E or W.
• Speed over ground, 0.0 to 1851.8 knots.
• Course over ground, 000.0 to 359.9 degrees, true.
• Date, ddmmyy format.
• Magnetic variation, 000.0 to 180.O.
• Degrees
• Checksum.

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Course Over Ground and Ground Speed

• GPVTG,lt1gt,T,lt2gt,M,lt3gt,N,lt4gt,K,lt5gtltCRgtltLFgt
• True course over ground, 000 to 359 degrees.
• Magnetic course over ground, 000 to 359 degrees.
• Speed over ground, 00.0 to 999.9 knots.
• Speed over ground, 00.0 to 1851.8 ko/hr.
• Checksum.

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