Environmental data question

[shoots_5]

I think I am doing this correctly but thought I'd check. I'm using the shooter app for long range ballistics data in conjunction with a kestrel for gathering atmospheric conditions. When I take a barometric pressure reading, it is a pressure referenced to an altitude. I know my house is at 212 feet so I set the barometer to reference fom that altitude. So when I go out to shoot, the place I usually go is around 1700'. Today I think the barometer measured something around 28.58. If I check the box in the program that says "pressure is absolute", then I would just plug in whatever barometer reading I get at the shooting location right? Otherwise it asks for altitude and station pressure. Is one method more accurate than the other? Seems like the more I read the more confused on the subject I get, and I think there is a lot of bad info out there on the subject....so if you've got it figured out straighten me out please!

 

[nvbroncrider]

If I remember right if pressure is absolute it is already calculating for elevation.

 

[shoots_5]

Right, if the pressure absolute option is checked, it greys out the altitude box. My question is more on what reading from my kestrel do I use I guess. Should I set the reference altitude while at a known elevation and then use the barometer number for wherever I'm at, or should I set the reference altitude for the barometer at zero so that it is uncorrected for elevation?