HP RC3000 Manual Do Utilizador

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RC3000 Antenna Controller 
Chapter 3 
Detailed Operation 
 
 76  
3.2.2.3 Locate 
The LOCATE mode performs a calculation of the pointing angle (1.3.4) to a selected satellite based on 
the RC3000’s estimate of where the antenna is positioned (lat/lon) and oriented (true heading).  After the 
calculation is performed the user may initiate an automatic antenna movement to locate the selected 
satellite. 
When the mode is first entered the following screen appears. 
 
POS:    38
°56N  94°44W  180.0      LOCATE 
SAT:GALAXY 6    74.0W           AZ:-31.1 
                                EL: 40.0 
<1>SELECT NEW SAT        READY TO LOCATE 
 
POS:  38°56N 94°44W  180.0 
The POS: field shows the RC3000’s current estimate of antenna position.  If no estimate of antenna 
position is available, the RC3000 will automatically attempt to obtain position information from the 
navigation sensors (GPS receiver and fluxgate compass) if present. 
Mount Position Initialization.  In order to calculate a pointing solution, the RC3000 requires knowledge 
of the mount’s “position”.  The three components of mount position are latitude, longitude and true 
heading.   
The current latitude, longitude and true heading where the RC3000 believes the antenna is positioned is 
displayed on the top line.  The position data obviously affects the pointing angle that the RC3000 
calculates and is displayed as a crosscheck for the user in case the vehicle has been moved and the 
RC3000’s position has not been updated.   If the lat/lon or heading data is not considered valid by the 
RC3000, asterisks will be displayed in the appropriate field and the “parameter needed” message will be 
triggered in the location readiness field. 
The RC3000 polls the GPS receiver first to get latitude and longitude information.  If no communication 
with the GPS is received, the error message “GPS OFFLINE” will be displayed.  In this case the interface 
between the RC3000 and the GPS receiver would need to be checked.  If the RC3000 is communicating 
with the GPS receiver but the GPS indicates it has not yet been able to generate a valid lat/lon, then the 
message “NAV NOT READY” will be displayed.  The “NAV NOT READY” situation should not last for 
more than a minute.  If it does, then investigate whether or not the GPS receiver’s view of the sky is 
blocked by buildings, etc.   
If a valid lat/lon is received from the GPS then the lat/lon information will be displayed.  Next the RC3000 
will flash “MAGVAR” while it calculates the local magnetic deviation as a function of latitude, longitude 
and time.  After calculating the local magnetic variation, the RC3000 will poll the fluxgate compass for 
magnetic heading information.  The magnetic variation will be applied to the magnetic heading to form the 
estimated true heading of the mount.