Gps7 - Gps Position Uncertainty - Leica MX400 Operating Instructions Manual

Table of Contents

Appendix C - Engineering Mode

memory locations when the receiver is writing to memory. The end

result is a small piece of memory is corrupted. When that piece of

memory is used for another calculation, it causes another piece of

corrupted memory. While the receiver may appear to operate

correctly, over a long period of time (weeks or months) the receiver

will begin to operate unpredictably. Another source of possible

memory corruption is an aged Lithium memory back-up battery.

When the battery fails after a couple of years, there isn't enough

power to maintain all of the memory circuits at first. The result is

that you could have some memory that is perfectly intact, and other

memory which is lost or garbled.

There are many other possibilities of noise sources in the normal

operating environment of the receiver. While Leica has designed

the receiver to handle most of these circumstances, there is a limit

to what we can do to protect the unit from high power and aging

components. If some of the symptoms described here are found

while operating the receiver, you should take a hard look at the

installation of the entire system to ensure you have followed proper

procedures for: cabling, power, and most importantly grounding

and antenna placement. The majority of these problems will be

resolved by equipment grounding and antenna location selection.

Regarding grounding, the water intake for the engine, or any other

electrical ground relying on the engine or generator for Earth

ground is not good for the GPS and especially the beacon receiver.

The EL, AZ, and STA values represent the satellite's Elevation and

Azimuth, and Almanac Status respectively.