Does Radar Altimeter work when radar is silent?

[Windhawk]

I swear, i can see the CCIP line shift when I turn the radar on. This is while the radar altimeter has been on the whole time. So does the radar need to be on for the radar altimeter to work?

 

I'm trying to find the causes for my CCIP bombing inaccuracies.

[Frederf]

The CCIP calculation uses one of three methods: fire control radar for slant ranging, radar altimeter for height, or neither.

 

The FCR is the priority measurement tool so if TAS and RS are both selected TAS is used (RS is standby if TAS failure). You will see a change in solution when changing between RS and TAS measurement because the methods give different solutions.

 

Conditions:

600 KIAS, 400' over ocean, level flight, BF1

 

TAS: 202 mil

RS: 210 mil

 

However depriving the FCR of data by turning it off it won't use RS directly like it has some sort of memory of the FCR data. However deselecting TAS manually does revert to the RS source.

[Zeus67]

I swear, i can see the CCIP line shift when I turn the radar on. This is while the radar altimeter has been on the whole time. So does the radar need to be on for the radar altimeter to work?

 

I'm trying to find the causes for my CCIP bombing inaccuracies.

 

Radar ranging has priority over the radar altimeter for obvious reasons: The radar looks ahead and can determine target elevation before the CCIP gets there.

 

The radar altimeter only determines ground elevation below the aircraft, that value is used for CCIP with the understanding that the target elevation not necessarily is equal to ground elevation below the aircraft.

 

If both are used, the radar ranging will take precedence.