S
YSTEM
P
ARAMETERIZATION AND
O
PERATION
6842 GPS Slim Line System - V09.01
37 / 98
hopf
Elektronik GmbH
Nottebohmstr. 41 • D-58511 Lüdenscheid • Tel.: +49 (0)2351 9386-86 • Fax: +49 (0)2351 9386-93 • Internet: http://www.hopf.com • E-Mail: info@hopf.com
4.1.2.4 Satellite Values (GPS)
This display function indicates the number of satellites that theoretically lie in the visibility
range of the antenna, the satellites that are being received and a relative measurement of
reception performance. This information is particularly helpful during installation and analysis
of reception problems (see
Chapter 7 System Indicators / Fault Analysis /
Troubleshooting
).
If the System is set for 3D synchronization (see
Chapter 4.1.4.4 3D / Position-fix GPS
Reception and Synchronization Mode
), it is necessary for four satellites to be in the
visibility range of the antenna in order to synchronize the GPS System 6842 with UTC and to
calculate the position. Under optimum conditions approx. 9-14 satellites are in the visibility
range of the antenna, of which 12 can be received in parallel.
In the Position-fix mode at least one satellite is required for synchronization (however the
position is not calculated in this case).
Selection frame:
S H O W S A T E L L I T E S
Y / N _
If values are available in the System then the display frame may appear as follows
(example):
Display frame:
V 2 0 : 0 9 5 1 3 : 0 9 0
1 0 0 7 : 0 5 7 :
10 satellites are theoretically within visibility range, of which satellite 20 is captured by the
GPS receiver with a relative signal/noise ratio of 95 and satellite 7 with a relative signal/noise
ratio of 57, etc.
A maximum of eight satellites can be shown on the display. This takes place on two frames
which are shown alternately every five seconds.
The number of satellites which are visible at this location with a theoretically optimum
antenna position appears under
V
(visible). During the first reception process or after a
lengthy voltage failure the value
00
appears under
V
.
If there are no figures under
V
Ö
there is a fault on the GPS receiver.
The figure before the colon is the Satellite Pseudo Random Number. The satellites are not
identified by 1, 2, 3 etc. but by the Pseudo Random Number under which the satellite
radiates its information. If a satellite fails a reserve satellite can be activated under the same
number.
The number after the colon indicates the signal/noise ratio as a relative value. This can vary
between 0 and 255.
After the first installation it can take up to 30 minutes under the most unfavourable conditions
until anything is presented on the display frame. This is dependent on the start information
which the System receives (see Input Time, Position etc.) as well as the antenna position,
e.g. no free antenna visibility to the sky.
Meaning of the Display Values
Signal/Noise Ratio
No satellite received
~~~
Under poor signal/noise conditions the values lie between
010 - 029
Under satisfactory to good signal/noise conditions the values lie
between
030 - 057
Under very good signal/noise conditions the values are
060 - 108