Leica Geosystems GPS System 500 - Technical Reference Manual - Manual (Page 341)

341 Appendix H Technical Reference Manual-4.0.0en
Radio Modems and Channel
Switching
Channel switching is supported with
Satelline 2ASx, 2ASxE, 3AS/3ASd
and Pacific Crest RFM96 modems. It
offers you the ability to set the chan-
nel on the radio modem.
This changes the frequency at which
the radio operates by a small amount.
This can be used in the following
situations:
Case 1
Two Real-Time Reference stations
are set up at two locations, each
broadcasting on two different chan-
nels. This gives the Rover two advan-
tages:
1. If the signal from one reference
station is blocked, you can switch
channels and try the other one.
2. You can obtain two separate
fixes for each point, providing redun-
dancy for future least squares adjust-
ment operations.
Case 2
One Real-Time Reference and one
Real-Time Rover are being used. If
the signal is blocked due to radio
interference, you can switch the
channel at the Reference and Rover
to try a slightly different frequency.
Note that when using channel switch-
ing, the Ref Stn Id at the Reference
should be set to a different Id for each
reference site.
The number of channels available
and the frequency spacing between
channels will depend on the radio
modem used.
Channel switching on Pacific Crest
Radio Modems must be activated by
a Pacific Crest dealer and may
require a special license.
Satelline Radio Modems must be in
Programming mode. This can be set
by a Satelline dealer. Channel switch-
ing may contravene radio broadcast-
ing regulations in certain countries.
Make yourself aware of the regula-
tions in force in the area in which you
are operating.