Mitel GPS Orion-S/-HD Receiver - Manual (Page 29)

Document Title: 25
User’s Manual for the GPS Orion-S/-HD Receiver
Document No. Issue 1.0
GTN-MAN-0110 June 22, 2003
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DLR/GSOCNo part of this document shall be reproduced in any form or disclosed to third parties without prior authorization.
4.3.1.4 MC – Media Correction
The MC command controls the application of media corrections to the raw measurements
prior to computing the navigation solution. The resulting status of the tropospheric correction
switch is confirmed by either of the following command replies:
I-MC-Tropospheric correction disabled
I-MC-Tropospheric correction enabled
E-MC-Ignored (invalid argument #1)
A second command reply out of
I-MC-Ionospheric correction disabled
I-MC-Ionospheric correction enabled
E-MC-Ignored (invalid argument #2)
gives the status of the tropospheric correction switch.
CmdID Chars. Format Description
MC 7 Media Correction
1 x <STX>
2 xx Command Id (=MC)
1 x Tropospheric correction (0=disabled ,1=enabled)
1 x Ionospheric correction (0=disabled ,1=enabled)
2 xx Checksum
1 x <ETX>
Notes:
•
Media corrections are applied only to pseudorange measurements but not to range
rate data.
•
No corrections are applied for GPS satellites below the horizon (0° elevation).
•
The tropospheric range correction is altitude dependent and decreases exponentially
with a scale height of 7.5 km. It is thus applicable for all types of applications (terres-
trial, ballistic, and LEO satellites)
•
The ionospheric range delay is computed from the standard Klobuchar model, which
can only provide a coarse correction of the true effect. In particular, the model does
not depend on the actual altitude of the receiver. For LEO satellite applications, it is
recommended to deactivate the ionospheric correction.
Example:
<STX>MC000E<ETX>
Deactivate all corrections
<STX>MC110E<ETX> Activate all corrections
<STX>MC100F<ETX> Activate tropospheric correction only