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Magellan GPS 320 User Manual

Page 64

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56

Magellan GPS 315/GPS 320

GSA

GPS DOP and Active Satellites

GPS receiver operating mode, satelites used in the navigation

solution reported by the $--GGA sentence, and DOP values.

1 2 3 4 5 6 7

GSA,a,x,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,x.x,x.x,x.x*hh,

1

Mode: M=Manual, forced to operate in 2D or 3D mode,

A=Automatic, allowed to automatically switch 2D/3D

2

Mode: 1= Fix not available, 2=2D, 3=3D

3-4

PRN numbers of satellites used in solution (null for unused

fields)

5

PDOP

6

HDOP

7

VDOP

GSV

GPS Satellites in View

Number of satellites (SV) in view, PRN numbers, elevation,

azimuth and SNR value. Four satellites maximum per transmis-

sion, additional satellite data sent in second or their

message. Total number of messages being transmitted and the

number of messages being transmitted is indicated in the

first two fields.

1 2 3 4 5 6 7 8 9 10 11

GSV,x,x,xx,xx,xx,xxx,xx.........,xx,xx,xxx,xx*hh

1

Total number of messages, 1 to 9

2

Message number, 1 to 9

3

Total numer of satellites in view

4

Satellite PRN number

5

Elevation, degrees, 90

° maximum

6

Azimuth, degrees True, 000 to 359

7

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

8-9

2nd-3rd SV

10-11 4th SV

Notes: 1) Satellite information may require the transmission

of multiple messages. The first field specifies the total

number of messages, minimum value 1. The second field identi-

fies the order of this message (message number), minimum

value 1.

2) A variable number of “PRN-Elevation-Azimuth-SNR” sets are

allowed up to a maximum of four sets per message. Null fields

are not required for unused sets when less than four sets are

transmitted.