Using StrelokPro.
Sorry to open an old can of worms for some, but should I be using Density Altitude in my Ballistics App?
- Thread starter JustMissedIt
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I have Strelok Pro. I use Temp, Station Pressure, and Humidity is kept at 50%.
Temp comes from a thermometer or my Kestrel 2000, and station pressure from my watch.
People say they like using DA because it is only a single number. I guess 2 numbers are just too much for them to handle.
Temp comes from a thermometer or my Kestrel 2000, and station pressure from my watch.
People say they like using DA because it is only a single number. I guess 2 numbers are just too much for them to handle.
Temp and absolute pressure will be more accurate than using DA. Speed of sound in air is solely dependant on temperature and will throw off your Mach number calculation by a little.
+1 to pyrotechnic, this is it exactly.
as an example --
850.0 hPa, 10°C and 979.3 hPa, 30°C
have the same air density, 1.125 kg/m3
but don't have exactly the same trajectory, because, as pyrotechnic has rightly pointed out, the speed of sound is not the same
If using air density, practical error is usually not very big (something like ~0.3 mrad at 1km for a .308 class cartridge), but if an error can be avoided...
Also, unless using temperature-stable powders, the value of T is required for V0 anyway (because, if ignored, the effect is much more significant than 3 clicks at 1km).
as an example --
850.0 hPa, 10°C and 979.3 hPa, 30°C
have the same air density, 1.125 kg/m3
but don't have exactly the same trajectory, because, as pyrotechnic has rightly pointed out, the speed of sound is not the same
If using air density, practical error is usually not very big (something like ~0.3 mrad at 1km for a .308 class cartridge), but if an error can be avoided...
Also, unless using temperature-stable powders, the value of T is required for V0 anyway (because, if ignored, the effect is much more significant than 3 clicks at 1km).
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