logo
Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Options
Go to last post Go to first unread
Joe D.  
#1 Posted : Sunday, December 27, 2020 7:19:09 PM(UTC)
Joe D.

Rank: Newbie

Groups: Registered
Joined: 12/26/2020(UTC)
Posts: 6
Man
United States

Can barometric pressure ( if available) be used to calculate altitude for devices without gps?

Mark  
#2 Posted : Tuesday, December 29, 2020 11:10:58 AM(UTC)
Mark

Rank: Administration

Groups: Administrators
Joined: 4/12/2014(UTC)
Posts: 499

Was thanked: 9 time(s) in 8 post(s)
Looks like you need sea level pressure to start off with - https://keisan.casio.com/exec/system/1224585971
Joe D.  
#3 Posted : Tuesday, December 29, 2020 3:30:18 PM(UTC)
Joe D.

Rank: Newbie

Groups: Registered
Joined: 12/26/2020(UTC)
Posts: 6
Man
United States

Normal sea level barometric pressure is 29.9 inHg. Pressure drops by approximately. .95 inHg per 1000 ft.
That is how an altimeter works. The barometer would likely be more accurate than the gps would be. Weather will make it vary slightly but accuracy would still be very close.
Mark  
#4 Posted : Tuesday, December 29, 2020 3:53:25 PM(UTC)
Mark

Rank: Administration

Groups: Administrators
Joined: 4/12/2014(UTC)
Posts: 499

Was thanked: 9 time(s) in 8 post(s)
Ok, I'll give it a try. Still need outside temp, which the App gets from the ECM and is not always accurate but if it is, this may work.

Edited by user Tuesday, December 29, 2020 3:54:47 PM(UTC)  | Reason: Not specified

Joe D.  
#5 Posted : Thursday, January 7, 2021 4:25:39 PM(UTC)
Joe D.

Rank: Newbie

Groups: Registered
Joined: 12/26/2020(UTC)
Posts: 6
Man
United States

I think you can get by using 59 degrees F. You are not figuring density altitude, you are just wanting barometric pressure converted directly to altitude. Ambient temp shouldn’t make a difference because you are not trying to figure density.
Joe D.  
#6 Posted : Thursday, January 7, 2021 4:36:55 PM(UTC)
Joe D.

Rank: Newbie

Groups: Registered
Joined: 12/26/2020(UTC)
Posts: 6
Man
United States

Mark  
#7 Posted : Thursday, January 7, 2021 6:05:14 PM(UTC)
Mark

Rank: Administration

Groups: Administrators
Joined: 4/12/2014(UTC)
Posts: 499

Was thanked: 9 time(s) in 8 post(s)
Tried that and using standard sea level pressure of 1013.25 and a temp of 59F I was off on my home altitude (550 calculated vs 660 actual). Not sure if the difference would exaggerate itself the higher you go though so I'm still skeptical at implementing this. If anybody at a higher altitude wants to compare here is the conversion website - https://keisan.casio.com/exec/system/1224585971. Just put in your current pressure.
Mark  
#8 Posted : Thursday, January 7, 2021 6:13:45 PM(UTC)
Mark

Rank: Administration

Groups: Administrators
Joined: 4/12/2014(UTC)
Posts: 499

Was thanked: 9 time(s) in 8 post(s)
Well, I just put in the local pressure of Denver (1023.5) and it gave me an altitude of -279 feet. Don't think that's correct...
Joe D.  
#9 Posted : Friday, January 8, 2021 11:26:04 AM(UTC)
Joe D.

Rank: Newbie

Groups: Registered
Joined: 12/26/2020(UTC)
Posts: 6
Man
United States

You can’t use local pressure from a weather station... the weather barometer is corrected for altitude so everyone can compare their barometric pressure to sea level. You need a direct pressure reading.
Joe D.  
#10 Posted : Friday, January 8, 2021 11:31:54 AM(UTC)
Joe D.

Rank: Newbie

Groups: Registered
Joined: 12/26/2020(UTC)
Posts: 6
Man
United States

My barometer reading is 28.0 inches. Altitude is 1850 ft. It’s pretty close.
Mark  
#11 Posted : Friday, January 8, 2021 5:01:11 PM(UTC)
Mark

Rank: Administration

Groups: Administrators
Joined: 4/12/2014(UTC)
Posts: 499

Was thanked: 9 time(s) in 8 post(s)
Ok, I'll try again with my daughter in Ogden but it looks it may now work.
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.