Interesting information has come out of my lack of knowledge on this subject. Whole interesting world out there.
73...bruce Sent from my iPhone On Mar 21, 2019, at 9:07 PM, Jonathan Guthrie via BVARC <[email protected]> wrote: Supposedly I studied this in college and, if I correctly recall the class where they discussed the standard atmosphere, which is of course based on the atmosphere that we observe, at sea level the temperature goes down as altitude increases until it stops changing. Then it stays the same for a while. Then it goes up for a while. Then it stays the same for a while. Then it goes down for a while, and then stays the same for a while, and then it goes up and keeps going up and up and up. At that point, though, you've got less than a thousand or so atoms per liter, so it's not real clear what "temperature" means. I wouldn't say that the density and pressure work to raise the temperature, more that the mechanisms for what drives the temperature change as you go up in altitude. For example, at very high altitudes, there are more ways to get energy into the molecules that make up air, but it's harder to get the energy because the density is so low. The pressure and density decrease uniformly with increases in altitude, which is why you can talk about "pressure altitude" and "density altitude" but not "temperature altitude", and of course the temperature, pressure, and density are all related by air's equation of state. By the way, the "standard atmosphere" is based on something called "geopotential altitude" which redefines the foot (well, actually meter) of altitude to be such that the acceleration due to earth's gravity is constant. That means that a certain integral has a closed-form solution and there's a known conversion and fairly simple to the more usual "geometric altitude." I found that kind of interesting. > On 3/21/19 1:24 PM, john Parmalee via BVARC wrote: > Apparently there it a point the density and pressure work to raise the > temperature. It's one of those this that is linear until it's not. > > John Parmalee > [email protected] > 281-380-3811 > K5VGM WI2XLJ > In a message dated 3/21/2019 1:16:56 PM Central Standard Time, > [email protected] writes: > > i would have thought as the balloon gets higher with thinner air that the > temperature would get colder. you say it goes up. interesting. i may need > to take a look at that. neat experiment. > > 73...bruce > > Sent from my iPhone > > On Mar 21, 2019, at 1:10 PM, john Parmalee via BVARC <[email protected]> wrote: > > > Especially for those that won’t be able to make it to the Houston HamFest > this weekend. > > Two Balloon launches with ham gear on board. You can participate. > > Live video of both launches https://zoom.us/i/2815436502 > > 9:30 AM BLT-51 will launch > > You can track with http://APRS.fi search the call W5ACM-10. > > You can Google APRS to find the site. > > BLT-51 will be a floater, designed to be tracked via APRS and glide across > the country, and hopefully even further. The last one went to Florida in > about six hours. > > Around 1:00 PM another launch BLT-52 > > BLT-52 is a “popper.” Designed to go up as high as possible and burst, also > to be tracked via APRS. Last August a popper > flew to nearly 100,000 feet. “To the edge of > space.” > > W5ACM Cross-band FM repeater will be in board with with > > Input on 147.435 MHz ß-----à Output on 446.550 MHz no tone, open to all to > work > > A WB8ELK APRS Tracker on 144.390 MHz with the call W5ACM-11 will be on board. > > You can track at http://APRS.fi search for W5ACM-11 > > On board also the AB5SS Smart Beeper on 10 and 20M 14.318 & 28.322 mHz, the > temperature in CW call sign and BL-52. Wach as the balloon passes through > 60,000 feet the Temperature to rise. > > The video will also be recorded for later playback as well, and depending on > the size of the captures, they will either be in the groups.io FILES area > https://groups.io/g/Ham-Radio-Tech-Notes/files , or my website.K5WH.net > > . > > _______________________________________________ > BVARC mailing list > Radio,Radio,Radio We are a radio Club! > Talk it up! On the air about every event, every meeting, every net, every > time, talk about the club, ham fests, events and people. > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > Message delivered to [email protected] > _______________________________________________ > BVARC mailing list > Radio,Radio,Radio We are a radio Club! > Talk it up! On the air about every event, every meeting, every net, every > time, talk about the club, ham fests, events and people. > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > Message delivered to [email protected] > > > _______________________________________________ > BVARC mailing list > Radio,Radio,Radio We are a radio Club! > Talk it up! On the air about every event, every meeting, every net, every > time, talk about the club, ham fests, events and people. > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > Message delivered to [email protected] -- Jonathan Guthrie ARS KA8KPN _______________________________________________ BVARC mailing list Radio,Radio,Radio We are a radio Club! Talk it up! On the air about every event, every meeting, every net, every time, talk about the club, ham fests, events and people. [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org Message delivered to [email protected]
_______________________________________________ BVARC mailing list Radio,Radio,Radio We are a radio Club! Talk it up! On the air about every event, every meeting, every net, every time, talk about the club, ham fests, events and people. [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org Message delivered to [email protected]
