Re: [Flightgear-devel] Re: [Flightgear-cvslogs] CVS:
Melchior FRANZ wrote:
* Martin Spott -- Tuesday 17 August 2004 15:28:
I just realized you already calculate the rel. humidity from
temperature and dewpoint. You could calculate the cloud base from these
two numbers and the airport elevation as well - at least our instructor
taught us to do so in case of of doubt.
What? The cloud base from temperature and dewpoint?
Yes, the dew point represents the temperature, when humidity
precipitates. In wet adiabatic conditions, which are likely to
predominate, temperature decreases 1 degree Celsius per 100 m altitude.
Now you can calculate the height above GND of your cloud base if you
know elevation and the spread (temperature at GND - dewpoint).
And then:
$ ./metar -e `zcat $FG_ROOT/Airports/default.apt.gz|awk '/ LOWW /{print $5}'` -c
LOWW
I agree, this is a bit complicated for the average user ;-))
Maybe it would make more sense to intregrate this logic into FlightGear
in order to make the weather model more realistic,
Martin.
--
Unix _IS_ user friendly - it's just selective about who its friends are !
--
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[Flightgear-devel] Re: [Flightgear-cvslogs] CVS:
* Martin Spott -- Thursday 19 August 2004 13:16:
Melchior FRANZ wrote:
* Martin Spott -- Tuesday 17 August 2004 15:28:
I just realized you already calculate the rel. humidity from
temperature and dewpoint. You could calculate the cloud base from these
two numbers and the airport elevation as well
What? The cloud base from temperature and dewpoint?
Yes, the dew point represents the temperature, when humidity
precipitates. In wet adiabatic conditions, which are likely to
predominate, temperature decreases 1 degree Celsius per 100 m altitude.
Now you can calculate the height above GND of your cloud base if you
know elevation and the spread (temperature at GND - dewpoint).
OK. I read your sentence as: You could calculate the cloud base from
temperature and dewpoint. And you could also calculate the airport
elevation from them ... which would have been quite surprising (and
unbelievable).
And then:
$ ./metar -e `zcat $FG_ROOT/Airports/default.apt.gz|awk '/ LOWW /{print $5}'` -c
LOWW
I agree, this is a bit complicated for the average user ;-))
Maybe it would make more sense to intregrate this logic into FlightGear
in order to make the weather model more realistic,
That's of course done in fgfs!
m.
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Re: [Flightgear-devel] Re: [Flightgear-cvslogs] CVS:
Melchior FRANZ wrote: * Martin Spott -- Thursday 19 August 2004 13:16: Yes, the dew point represents the temperature, when humidity precipitates. In wet adiabatic conditions, which are likely to predominate, temperature decreases 1 degree Celsius per 100 m altitude. Now you can calculate the height above GND of your cloud base if you know elevation and the spread (temperature at GND - dewpoint). OK. I read your sentence as: You could calculate the cloud base from temperature and dewpoint. And you could also calculate the airport elevation from them ... My sentence has a different meaning: If you know elevation and spread (spread: temperature at airport elevation minus dewpoint), then you can calculate the cloud base, Martin. -- Unix _IS_ user friendly - it's just selective about who its friends are ! -- ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
[Flightgear-devel] FDM from file broken?
I saved out FDM information using -native=file,out,120,flight1.fgfs. When I try and read it back in using -native=file,in,120,flight1.fgfs --fdm=external, the aircraft just sits there. It looks like FGNative::process() is pulling data out of the file. Any ideas on what might be causing this? I'm using the latest source code release (0.9.5). Thanks, Vance ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: [Flightgear-flightmodel] Question: LevelA FAA certified flight dynamics models
No, I must confess you're correct Curt. I've also checked the JAR STD 1A and it's the same : a 3DOF motion base is required for a Level A Flight Simulator. http://www.jaa.nl/section1/jars/439120.pdf I've worked a couple of years for a simulator company on Level D Full Flight Simulators and I always thought that the Fixed Based Simulators (which were the exact copy of the FFS from a HW and SW point of view - but with no visual and no motion) were at least level A. I was wrong, it's only Flight Training Devices (FTD). Olivier - Original Message - From: Curtis L. Olson [EMAIL PROTECTED] To: FlightGear developers discussions [EMAIL PROTECTED] Sent: Thursday, August 19, 2004 12:06 AM Subject: Re: [Flightgear-devel] Re: [Flightgear-flightmodel] Question: LevelA FAA certified flight dynamics models By my reading of the following table, page 12: http://www2.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircula r.nsf/1ab39b4ed563b08985256a35006d56af/5b7322950dd10f6b862569ba006f60aa/$FIL E/Appx1.pdf Level A, and B certified simulators seem to require at least a 3 degree of freedom motion system. Am I misreading or misunderstanding something? The above link looks a little funny to me so if you have trouble with it, go to http://www.faa.gov/certification/aircraft/av-info/dst/ACreference/120-129.ht m Then scroll down to the AC120-40B section. The table is Appendix 1. Thanks, Curt. Olivier Soussiel wrote: Correct, for more information on what is exactly required for a level A simulator, see the FAR AC120-40B. http://www.faa.gov/certification/aircraft/av-info/dst/ACreference/120-129.h t m - Original Message - From: Gene Buckle [EMAIL PROTECTED] To: Flight dynamics model discussions [EMAIL PROTECTED] Cc: FlightGear developers discussions [EMAIL PROTECTED] Sent: Wednesday, August 18, 2004 9:44 PM Subject: [Flightgear-devel] Re: [Flightgear-flightmodel] Question: Level A FAA certified flight dynamics models Curt, are you sure you're not talking about a Level D simulator? AFAIK, Level A is the minimum acceptable standard, with no motion base. g. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
[Flightgear-devel] JSBSim paper and slides online
I have placed the paper I presented at the AIAA Modeling and Simulation Conference on the JSBSim web site. Click on the Documents link. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
