atmospheric inputs..specifically elevation

[stvnbrg]

I dont know if this is in the right section or not so my apologies if its not.

first off, what are you guys using for atmospheric inputs? are you using density altitude? corrected pressure? or manually inputting for station pressure and altitude? right now im using a corrected pressure which is accurate for sure, but using DA just seems easier. any thoughts or feed back? which ties in with my second question.

In regards to elevation, what are you calibrating your devices to? My GPS and also my Kestrel need to be calibrated, so I cant really calibrate them from each other! Taking the elevation off of a weather app from the nearest weather station does not seem nearly accurate enough.any insight?

 

[4xforfun]

I have both my Kestrel and my Shooter App set for absolute (uncorrected) PSI. That way I NEVER worry about what elevation I am at. Take the reading and punch it into the app....bang, you are done!!

 

[stvnbrg]

how are you finding your corrected pressure? what are you calibrating your kestrel too? My phone has a barometer but i just cant seem to trust it

 

[Canadian Bushman]

Like 4x4 i use the station pressure. (Uncorrected)

Im so close to sea level i can use weather apps, also my rangefinder will read pressure.

You can use gps for elevation, it really doesnt have to be exact. Couple yards either way wont hurt you using density altitude.

 

[elktaker]

Am I missing something? Isn't the elevation input just for an estimated air density? Or have I been doing something wrong? I just ignore elevation and put in my pressure, air temp and humidity.

In the last three times out at 6000', I have had pressures between 809 to 826 Mbar.

 

[royinidaho]

Check drop results of various uncorrected pressures, with all other inputs being identical, and you may not worry so much. Not that being accurate with baro pressure isn't important. While it is an important fish in the barrel it isn't the biggest important fish in the barrel.

Example: (300 Berger - ~3000 MV - 1K dope)

Elevation Baro Comeups-MOA
4480 25 "Hg 26.2
6600 23" 25.4
9500 21" 24.7

If the 1.5 MOA error from home to the mountain was all I had to worry about I've be pretty stress less. However, I enter the best number I have, every time!

(I sure hope my math is right!:roll eyes

 

[RockyMtnMT]

I started a post on this not too long ago and kinda showed my stupid side. I learn best when I do stuff wrong. So what I learned is corrected pressure is not a good number to look at unless you are a weather forecaster. (Best job ever. You don't have to be correct.) Use the elevation (this will be pretty darn close) or better yet use the station pressure. I print out a drop chart that I tape to rifle stock that is the average elevation of the area that I will be hunting and use it for the quicker shot. When time is available to really set up I use the station pressure from my weather meter.

Steve

 

[royinidaho]

Steve,

U nailed it!

 

[4xforfun]

Check drop results of various uncorrected pressures, with all other inputs being identical, and you may not worry so much. Not that being accurate with baro pressure isn't important. While it is an important fish in the barrel it isn't the biggest important fish in the barrel.

Example: (300 Berger - ~3000 MV - 1K dope)

Elevation Baro Comeups-MOA
4480 25 "Hg 26.2
6600 23" 25.4
9500 21" 24.7

If the 1.5 MOA error from home to the mountain was all I had to worry about I've be pretty stress less. However, I enter the best number I have, every time!

(I sure hope my math is right!:roll eyes

1.5 MOA at 1K is 15 inches. That is fairly significant!!

 

[royinidaho]

1.5 MOA at 1K is 15 inches. That is fairly significant!!

I knew there was something not right with my think'n. :roll eyes:

Keeping track of inches/MOA/MILs gives me the vapors!

Good catch. I shudda known better.