Navman 11 User Manual

50

MN002000A © 2004 Navman NZ Ltd. All rights reserved. Proprietary information and specifications subject to change without notice.

Message ID: GSA
Rate: variable
Fields: 17

$_GSA

Start of sentence and address field

$GPGSA

1

OP _MODE

Mode (Note 1)

a

A

2

FIX_MODE

Mode (Note 2)

x

3

3-14

SATN

PRNs of satellites used in solution (null for unused fields)

xx,xx,....

04, 16, 09, 24...

15

PDOP

Position dilution of precision (Note 3)

x.x

3.33

16

HDOP

Horizontal dilution of precision (Note 3)

x.x

1.96

17

VDOP

Vertical dilution of precision (Note 3)

x.x

2.70

CKSUM

Checksum

*hh

*06

<CR><LF>

Sentence terminator

<CR><LF>

Note 1: Mode (operating), M = manual (forced to operate in 3D mode), A = automatic (can automatically switch between 2D and 

3D).

Note 2: Mode (fix), 1 = fix not available, 2 = 2D, 3 = 3-D

Note 3: DOPs are based on the set of satellites above the elevation mask angle, this may differ from the set used for navigation.

Message ID: GSV
Rate: variable; defaults to 0.5 Hz
Fields: 19

 

$_GSV

Start of sentence and address field

$GPGSV

 1

MAX_MSG Total number of messages (1 to 3)

X

2

 2

NUM_MSG message number (1 to 3)

X

1

 3

NUM_SATS Total number of satellites in view

Xx

07

 4

SAT_PRN

Satellite PRN number (Note 1)

Xx

24

 5

ELEV

Elevation in degrees (90 degrees maximum) (Note 2)

Xx

60

 6

AZ

Azimuth in true degrees (000 to 359) (Note 2)

Xxx

216

 7

SNR

SNR (C/No) 00 to 99 dB, null when not tracking

Xx

50

 8-11

...

2nd satellite PRN number, elevation, azimuth, SNR (Note 1) xx, xx, xxx, xx

...

 12-15

...

3rd satellite PRN number, elevation, azimuth, SNR (Note 1)

xx, xx, xxx, xx

...

 16-19

...

4th satellite PRN number, elevation, azimuth, SNR (Note 1)

xx, xx, xxx, xx

...

 

CKSUM

Checksum

*hh

*75

 

<CR><LF> Sentence terminator

<CR><LF>

Note 1: The visible satellites may include one or more that are below the horizon. Since NMEA does not account for negative 

elevation angles, the elevation field will be null for these satellites.

Note 2: Azimuth and elevation are null when the satellite is in track, but a visible list is not available.

This message contains the Jupiter receiver’s 

operating mode, satellites used for navigation, and 

DOP values. The contents of the ‘GSA’ message 

are described in Table 3-48. 

Sample message:
 $GPGSA,A,3,04,16,09,24,,,,,3.33,1.96,2.70*

06 

This message contains the number of satellites 

in view, PRN numbers, elevation, azimuth, 

and Signal-to-Noise Ratio (SNR) values. Each 

transmission identifies up to four satellites (max); 

additional satellite data is sent in a second or third 

message. The total number of messages being 

transmitted and the number of the message being 

transmitted is indicated in the first two fields. The 

contents of the ‘GSV’ message are described in 

Table 3-49. 

Sample message:
$GPGSV,2,1,07,24,60,216,50,20,47,135,47,12, 

40,020,47,16,36,319,46*75