Trying to decide whether or not to interface Density Altitude into TRA

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Michael Eichele, Jan 18, 2007.

  1. Michael Eichele

    Michael Eichele Well-Known Member

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    I am looking for opinions and/or feedback on using density altitude in ballistic software.

    Alot of shooters here use the Kestral 4000 which will give you DA. Is it something you guys want to be able to use instead of entering all the typical atmospheric fields or would you all rather enter temperature, pressure, humidity, etc...?
     
  2. Gustavo

    Gustavo Writers Guild

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    I really don't see the need for it. In fact using DA won't solve the problem at all...

    On the other hand, the use of Standard Conditions solves very accurate the firing solution.
     

  3. Michael Eichele

    Michael Eichele Well-Known Member

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    Not really trying to solve any problems. If anything it would be a convinience to use that option. I guess I am just looking to see if there is any interest in the use of it.
     
  4. CatShooter

    CatShooter Well-Known Member

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    Re: Trying to decide whether or not to interface Density Altitude into

    [ QUOTE ]
    Not really trying to solve any problems. If anything it would be a convinience to use that option. I guess I am just looking to see if there is any interest in the use of it.

    [/ QUOTE ]

    I spoke with the people that wrote the Sierra software last spring about this - at first they didn't know what I was talking about. After a few e-mails, they said that the next upgrade would incorporate a "switch" in the environmental menu that will allow picking standard altitude "0"FABMSL, and you enter local altitude, and the baro from the local weather station or airport, and the sofware will correct the baro (1" baro for each 1000 ft)... or, you can over-ride that, and the altitude will always be locked at "0" FAMSL, and you enter only the local baro from your Kestral.

    The upgrade is to be out "Sometime in 2007".

    .
     
  5. Mikecr

    Mikecr Well-Known Member

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    I think it would be a good option for those who wish to use it. But it'll surely bring on more confusion unless all other inputs are disabled.
    I'll see if I can post a method of use in the pinned thread "Altitude -vs- Barometric pressure".
    Won't be easy given many bullet BCs are referenced to StdMetro vs ICAO(from which DA holds applicability). Looks like a DA bias of 625 is needed for StdMetro conditions to prevent errors in standards.
     
  6. Michael Eichele

    Michael Eichele Well-Known Member

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    Re: Trying to decide whether or not to interface Density Altitude into

    [ QUOTE ]
    a "switch" in the environmental menu that will allow picking standard altitude "0"FABMSL, and you enter local altitude, and the baro from the local weather station or airport, and the sofware will correct the baro (1" baro for each 1000 ft)... or, you can over-ride that, and the altitude will always be locked at "0" FAMSL, and you enter only the local baro from your Kestral.


    [/ QUOTE ]

    That is exactly what TRA already does.
     
  7. Michael Eichele

    Michael Eichele Well-Known Member

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    [ QUOTE ]
    But it'll surely bring on more confusion unless all other inputs are disabled.

    [/ QUOTE ]


    Yes, I was thinking the same thing. All other atmospheric fields would be set to a default and eliminated or disabled upon checking the option to use DA.
     
  8. Gustavo

    Gustavo Writers Guild

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    [ QUOTE ]
    [ QUOTE ]
    But it'll surely bring on more confusion unless all other inputs are disabled.

    [/ QUOTE ]


    Yes, I was thinking the same thing. All other atmospheric fields would be set to a default and eliminated or disabled upon checking the option to use DA.

    [/ QUOTE ]

    The use of DA bring no advantage at all, except to those who have it readily available in the Kestrel.

    But...is it useful for us shooters? the short answer is NO.

    Again, use of STANDARD CONDITIONS (Metro or ICAO) are the way to go. You can check Sierra's explanations where it's perfectly explained.

    So any shooter trying to find a shortcut...will find only find a dead-end.

    The shortcut is already there.
     
  9. Michael Eichele

    Michael Eichele Well-Known Member

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    [ QUOTE ]
    Again, use of STANDARD CONDITIONS (Metro or ICAO) are the way to go. You can check Sierra's explanations where it's perfectly explained.

    [/ QUOTE ]

    I would have to dissagree. Unless of course I am not understanding what you are saying. This is what I think you are saying: Use standard conditions for whatever conditions you are shooting in. You have to use current condition to get accurate ballistics. Using DA would be a short cut, but FAR from a dead end. If it is not usefull to you, then your vote counts as such.

    [ QUOTE ]
    The use of DA bring no advantage at all, except to those who have it readily available in the Kestrel.


    [/ QUOTE ]

    Correct. Scince most here use the Kestral 4000, I thought I would see what the demand was.
     
  10. Gustavo

    Gustavo Writers Guild

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    [ QUOTE ]
    [ QUOTE ]
    Again, use of STANDARD CONDITIONS (Metro or ICAO) are the way to go. You can check Sierra's explanations where it's perfectly explained.

    [/ QUOTE ]

    I would have to dissagree. Unless of course I am not understanding what you are saying. This is what I think you are saying: Use standard conditions for whatever conditions you are shooting in. You have to use current condition to get accurate ballistics. Using DA would be a short cut, but FAR from a dead end. If it is not usefull to you, then your vote counts as such.

    [ QUOTE ]
    The use of DA bring no advantage at all, except to those who have it readily available in the Kestrel.


    [/ QUOTE ]

    Correct. Scince most here use the Kestral 4000, I thought I would see what the demand was.

    [/ QUOTE ]

    Sorry if I wasn't clear enough. I do not advocate the use of STANDARD CONDITIONS for accurate results, of course not.

    But the use of standard conditions, are a good enough compromise, when nothing better is available.

    Of course, much better and less confusing than using DA, just use altitude and for ranges uo to 600 yards yiedls results that are more than acceptable. /ubbthreads/images/graemlins/smirk.gif
     
  11. 284STW

    284STW Well-Known Member

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    I'm just curios, cause I really don't know anything about this stuff. I was under the impression that altitude+temp+baro pressure all made up density altitude. So if you knew what the density altitude was you wouldn't have to input everything else? Would it be the same as inputing everything else?
     
  12. Michael Eichele

    Michael Eichele Well-Known Member

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    I believe you are correct.

    DA = temp, pressure and humidity. Altitude isnt a factor scince BP is read.

    Adding an option to use DA would allow a user to enter one number instead of 3 or 4. Is it simpler or more complicated? Thats what I am trying to decide.
     
  13. drpbroun5

    drpbroun5 Well-Known Member

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    Much simpler.
    Paul