Leaders in Pipelin
e Survey Systems
C
C
C
-
-
-
S
S
S
C
C
C
A
A
A
N
N
N
2
2
2
0
0
0
1
1
1
0
0
0
SYSTEM MANUAL Version 6.03i
72
11.5. Clearing the Detector Memory
When all data from the Detector has been downloaded it is advisable to clear the memory.
From the Detector’s MENU screen select
CLEAR
and press to confirm.
12. GPS
GPS is an abbreviation for Global Positioning System which consists of 24 satellites in
low-earth orbit. The GPS receiver in C-SCAN receives data from a number of these
(maximum 12), depending on which satellites are ‘in-view’.
When first turned on, the GPS unit attempts to acquire the satellites that are in-view.
Acquisition times can be as quick as 2-30 seconds, but can be significantly longer. If the
Detector has been moved a large distance or it is the first time the Detector has been
used, acquisition time is likely to be longer. Although not essential, downloading the GPS
Almanac will assist in faster acquisition times in the future. The Almanac will automatically
download but needs around 15 minutes of continuous GPS data. To do this, leave the
detector in search mode with the GPS switched ON for at least 15 minutes.
The minimum number of satellites needed to calculate a position is 3. The more satellites
that are acquired, the more accurate the displayed position will be.
The SEARCH screen will display the co-ordinates of the last good signal, so if signal is lost
for any reason the position displayed could be incorrect. To confirm if the co-ordinates
displayed are current simply press the
GPS SAT
key which will display the status of the
GPS signal and the number of satellites acquired.
Fig 12.1 – Latitude / Longitude
position of the C-Scan Detector
Fig 12.2 – GPS signal ‘GOOD’ with
number of satellites shown
In the example above, Fig 12.1 displays the GPS position. Pressing
GPS SAT
changes to
GPS status, which in Fig 12.2 is
GPS: GOOD SAT:#6
.
The
GPS SAT
key now changes
to
GPS POS
(GPS Position) allowing you to switch between the number of satellites in
view and the Latitude & Longitude position of the Detector.
The GPS status indicator will show the following messages:
GPS: ACQUIRING - System is searching for GPS satellites. This message will be
displayed until 3 satellites are acquired, as a minimum of 3 are
require for positional data.
GPS: GOOD
- 3 or more satellites have been acquired to give positional data.
GPS: BAD
- The current position is incorrect, or satellites have not been
acquired or have lost acquisition.
GPS: OLD
- The data is more than 10 seconds out of date. As GPS data is
normally updated every 1 second, this could mean that
acquisition is about to be lost.
GPX
- The Detector is taking its GPS co-ordinates from an external
