Maretron gps200 Manuale Utente

 

 

 

 

 

4:  Latitude – Latitude in 1x10

-16

 degrees ("-" = south, “+” = north) 

 

5:  Longitude – Longitude in 1x10

-16

 degrees ("-" = west, “+” = east)  

 

6:  Altitude – Altitude referenced to WGS-84 in (resolution of 1x10

-6

 m) 

 

7:  Type of System – This field is used to indicate type of GPS system. The GPS200 will 

show either 0 (GPS) or 3 (GPS+SBAS, factory default) dependent on whether the 
user has enabled SBAS. 

 

8:  Method, GNSS – This field is used to indicate the quality of GNSS information. The 

GPS200 indicates one of the following values: 0=no GPS, 1=GNSS fix, 2=DGNSS 
fix, 6=Estimated (dead reckoning). 

 

9:  Integrity – This field always contains a value of 0 (no integrity checking). 

 

10:  Reserved (6 bits) – This field is reserved by NMEA; therefore, this field always 

contains a value of 0x3F (the GPS200 sets all reserved bits to a logic 1) 

 

11:  Number of SVs – This field is used to indicate the number of satellites used in 

solution. 

 

12:  HDOP – This field is used to indicate the horizontal dilution of precision with a 

resolution of 1x10

-2 

(unitless). 

 

13:  PDOP – This field is used to indicate the positional dilution of precision with a 

resolution of 1x10

-2 

(unitless). 

 

14:  Geoidal Separation – This field is used to indicate the Geoidal Separation in 

resolution of 1x10

-2

 m. 

 15: 

Number 

of 

Reference 

Stations – This field always contains a value of 0 

 

16:  Reference Station Type "1" – This field always contains a value of 0xF (Null) 

 

17:  Reference Station ID "1" – This field always contains a value of 0xFFF (data not 

available) 

 

18:  Age of DGNSS Corrections "1" – This field always contains a value of 0xFFFF (data 

not available) 

 
PGN 129539 – GNSS DOPs 
The GPS200 uses this PGN to provide a single transmission containing GNSS status and 
dilution of precision components (DOP) that indicate the contribution of satellite geometry to 
the overall positioning error. There are three DOP parameters reported, horizontal (HDOP), 
Vertical (VDOP) and time (TDOP). The factory default for periodic transmission rate is once 
per second. The transmission of this PGN can be disabled or the transmission rate of this PGN 
can be changed (see PGN 126208 – NMEA Request Group Function – Transmission Periodic 
Rate). 
 Field 1:  SID – The sequence identifier field is used to tie related PGNs together. For 

example, the GPS200 will transmit identical SIDs for 126992 (System Time), 128259 
(Speed), 129026 (COG and SOG, Rapid Update), 129029 (GNSS Position Data), 
129539 (GNSS DOPs), and 129540 (GNSS Satellites in View) to indicate that the 
readings are linked together (i.e., the data from each PGN was taken at the same 
time although they are reported at slightly different times). 

 

2:  Set Mode – This field is used to indicate the desired mode of operation: 0 = 1D. 1 = 

2D, 2 = 3D, 3 = Auto (factory default), 4-5 = Reserved, 6 = Error, 7 = Null. The 
GPS200 will always return a value of 3 for this parameter. 

 

3:  Op Mode – This field is used to indicate the actual current mode of operation: 0 = 

1D. 1 = 2D, 2 = 3D, 3 = Auto (factory default), 4-5 = Reserved, 6 = Error, 7 = Null.