Density Altitude w/a Ballistics Program

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by bill123, Nov 20, 2013.

  1. bill123

    bill123 Well-Known Member

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    I have a Kestrel that I use to get my DA. I then put the DA into Ballistic AE which also asks me for the Temp or Mach.

    Here's my question. DA is calculated as:
    Pressure Altitude + [120 x (OAT - ISA Temp)]

    OAT is local temperature from a thermometer.
    ISA Temp is always 15 °C at sea level.

    From that formula, it looks like DA includes temperature already. Why is Ballistic AE asking for Temp. again?
     
  2. bill123

    bill123 Well-Known Member

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    Got the answer myself. The Atmosphere pages ask for Temp to calculate Mach. DA already takes Temp. into account.
     

  3. MMERSS

    MMERSS Well-Known Member

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    Additionally,

    If your ballistics program is using temperature regression for correcting MV according to powder temperature you will need the temperature. Another consideration when using DA requiring a separate temperature input.
     
  4. bill123

    bill123 Well-Known Member

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    Thanks, I'll look into that as well.