GSSI SIR 20, Руководство пользователя

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Geophysical Survey Systems, Inc. SIR® 20
Manual
MN92-078 Rev F 68
Figure 72: GPS Enable Window.
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If your GPS is functioning and communicating with the SIR 20, you will see location information, a
time stamp, number of satellites detected, a measure of signal quality, and either Data Valid or
Invalid. Your location information will not be adequate if you are tracking fewer than 4 satellites.
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Click Next to continue with new project setup.
Understanding GPS
This is a brief description of GPS. GPS information gets attached to our data two different ways. First, the
start and end positions are stored in the header of each *.DZT file. Second, the timing for each marked
scan is stored in a separate *.TMF file, which RADAN 6.0 and higher incorporates into its database.
This section gives a quick GPS overview and then describes what you need to know in order to
effectively use the SIR 20 with a GPS.
What is it?
GPS is a satellite navigation system (provided free by the USDoD) designed to
provide instantaneous position, velocity and time information almost anywhere on
the globe at any time, and in any weather. It typically provides positioning
accuracies ranging from 3 meters (costing $150) to 1cm ($15,000). Since it needs to
see much of the sky, it works poorly indoors, in woods and in “concrete canyons”
like Manhattan.
Why do I need it?
You probably don’t! In fact for many Ground Penetration Radar applications you can just use a survey
wheel to measure your distance and take simple notes about your start and stop locations. And since
digging or drilling often requires more precision than 3 meters, knowing “sort of” where you are is not
helpful.