From: Roy V. O. <roy...@ha...> - 2007-02-25 19:39:57
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On Sunday 25 February 2007 19:44, John Denker wrote: > Parts? I didn't know the class has an altimeter part separate > from the encoder part. The class can be /configured/ to be one > or the other. It cannot and should not be configured to be both. I suggested an encoding altimeter as an instance that has both. Do you think that makes sense? > > > AFAIK an encoder never outputs > > indicated altitude. > > 1) We can agree that /usually/ the encoder does not put out indicated > altitude. But there *are* backup altimeters that do display an > indicated altitude derived from the encoder (quantization and all). > This is not super-important. > > 2) The main reason for that feature was (a) because it was easy to do, and > (b) to make life super-easy when writing autopilot code, so that the > Kollsman shift could be calculated in one simple step, by subtraction. > If the autopilot authors are not interested in doing that, they are > requested to please ignore the indicated altitude output. Please > don't complain about "bugs" in something that is both realistic and > harmless. > > I've heard opinions, but I haven't heard any explanation of why > quantizing the pressure altitude is either unrealistic *or* unhelpful. I have not, and I don't think Dave Perry has either, expressed optinions to indicate that the pressure altitude should not be quantized. What we have said is that indicated altitude should not be quantized. -- Roy Vegard Ovesen |