Date   
Re: Herington newspaper

Don Pfister <ka0jlf@...>
 

After my forgetfullness, I did contact J.R. again yesterday - thanks to kd0fw
reminding me. He was going to check and see how many copies he had and send me upto
24. He was going to call me back but I didn't get a call or message.

I will follow up on this. I will mail copies to those of you that have told me you
wanted one (or more). I hope to mail copies out next week.

I found out they are $1 each plus postage. They charge the price of the paper ($1 an
issue) even for the tear sheets. To avoid the additional postage/shipping I just got
tear sheets.

More later, let me know if you have any questions. Oh, Mark in answer to your
question yes that is the paper but the area code changed to 785 like Doug said.

IF this list isn't everyone, please pass this on to your groups or lists.

Don
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Name=Don Pfister KA0JLF
PFranc of KS - GPS cables and connectors
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Don Pfister wrote:

I talked to J.R. he said they ran an article with 3 photos. He wants to know how
many copies we want and where to send them to. I told him I thought tear sheets
were ok, not the whole issue, is that right?

How do you want to do this? You want them sent to me and then I will send them
to you or should we just have them mail them out. I didn't ask about cost yet, I
thought until we could answer how many, the cost wouldn't matter much. I'm
afraid a qty would make a difference.

Let me know,
Don

Doug Eubanks wrote:

J.R. Sparke785-258-2211

----- Original Message -----
From: Don Pfister
To: GPSL@...
Sent: Friday, July 12, 2002 7:25 PM
Subject: Re: [GPSL] Herington newspaper
Anyone remember his name from the reporter? I'll give them a call.

Mark Conner wrote:

> Our media coverage for GPSL consisted of the local (weekly?) newspaper
> coming out that morning. I found on Google a listing for the following
> paper:
>
> HERINGTON TIMES 7 N BROADWAY HERINGTON, KS 67449-2401 913-258-2211

>
> If no one's already arranged for this, I'd like to call them and get a
> few copies. Don, is this the correct paper?
>
> - Mark

Herington Airport Fly-In

paul.verhage@...
 

Don and Zack, I just got a phone call from the airport manager at
Herington. Their Fly-In is on Sept 7. He'd like you to contact him
about a balloon launch at the Fly-In.

Paul

Re: MIM?

Don Pfister <ka0jlf@...>
 

Perhaps the MIM is no longer available. I sent an email to Bob and asked. I'll let
you know what I find out.

Don

Don Pfister wrote:

Mr. APRS himself, Bob Bruninga WB0APR. He bought the MIM from ... well whoever.
The last one I bought from him directly a few years ago.

Don

paul.verhage@... wrote:

How do we order MIMs now? Who is selling them?

Thanks,
Paul

Balloon Ascent Speeds

paul.verhage@...
 

In my book I discuss technical issues like the lift of helium,
descent speeds of parachutes, cosmic rays, etc. The next topic
I'm tackling is the ascent speed of a balloon. Here's what I have for
my notes so far. I'm looking for input, because I don't have the
complete picture yet. Please spend a little time looking these
notes over and making suggestions. Thanks.

A. Intro

We know the balloon will expand as it rises due to decreasing air
pressure. As a gas expands, as in a balloon, it cools. This
cooling decreases the volume of a gas. We can see that during a
flight that the balloon expands a lot more due to reduced air
pressure than it contracts due to cooling air temperatures (both
inside and outside the balloon). So cooling has a minor effect
compared to reducing air pressure. The forces acting on a balloon
are three, payload weight (W) pulling down, lift (L) pulling up, and
drag (D) pulling in the direction opposite of the balloon's motion (so
drag pulls down, just like the weight). Looking at flight data, we
see that the balloon ascends at a constant rate for the entire flight
[1]. As long as there is no net force acting on a balloon (or any
object for that manner), it moves with zero acceleration, or
constant velocity. Since the balloon climbs at a constant
veleocity, the force of lift of the balloon is balanced by drag and
weight, D + W = L. Lift and weight are constant on a balloon flight
[2], therefore the force of drag must be a constant throughout the
flight also.

B. Drag

The equation for drag is given as,
D = Cd * Ra * sq(V)/2 * rho

where,
Cd is a coefficient of drag
Ra is the reference area
sq(V)/2 is the square of the velocity, divided by 2
rho is the density of the air.

Cd is a dimensionaless constant. This means it's simply a
number and does not have any units (like pounds or feet) attached
to it. For a sphere, Cd is about 0.5

Ra is an area you choose to use. If you select a different area as
your Ra, then the Cd for that Ra is different, but Cd is still just a
number

I only what to determine how ascent speed changes as the
variables change, so I'm going to treat this equation as a
relationship of proportionality and drop the constants for the rest of
this discussion.

When you look at the US Standard Atmosphere (a model of how
air pressure, density, and temperature change as a function of
altitude), you see that the change in air density closely tracks the
change in air pressure. So I'm going to replace air density with air
pressure. The reason I do this is that we can see the change in air
pressure changes the balloon's volume and therefore it's reference
area. As a Ra, I'm going to select the frontal area occupied by the
balloon. This Ra is proportional to the two-thirds power of the
volume. The balloon's volume, ideally, is proportional to the inverse
of the air pressure. Observations show that the balloon's vertical
velocity, its ascent rate, is constant throughout a flight. So sq(V)/2
is also a constant. When I combine like terms and move the
constants out, I end up with the following,

D is proportional to (volume)^2/3 * pressure

Which simplifies to

D pro to 1/(pressure)^2/3 * pressure

Which simplified to

D pro to (pressure)^1/3

However, D must be a constant, whereas pressure is not a
constant! So what's wrong here?

The change in temperature can't be responsible for adjusting the
change in volume (that is due to changing air pressure) because
we see the temperature change in opposite direction in the tropo
and stratosphere. And yet, the ascent rates in both the tropo and
stratosphere are both constant.

So it appears to me that Cd is not a constant throughout a flight.

C. Cd

Cd models drag's depenedencies on things like shape, air
viscosity, and air compressibility. The balloon's shape does not
change significantly during a flight. The air compressiblity is not
siginificant belows speeds of 200 mph. This leaves only air
viscosity. Is the change in the air's viscosity proportional to the
cube root of the air's pressure? If so, the change in Cd would
oppose the chnage in drag caused by the change in air pressure
(or more exactly, air density). Does the Cd of an aircraft change
as the aircraft climbs?

Note 1
There is a knee in the ascent speed of a balloon as you approach
the stratosphere. In the startosphere, the air temperature
increases as the balloon climbs. Perhaps the slight extra increase
in the balloon's diameter due to increasing stratospheric
temperatures increases the balloon's drag slightly, causing it to
slow down a bit. As a future experiment, does a black balloon rise
faster than an identical white balloon or slower?

Note 2
The lifting ability of helium does decrease with decreasing
pressure. But this amounts to only something like a percent or
two. This is not enough to significantly effect our numbers.

Paul

Re: MIM?

Don Pfister <ka0jlf@...>
 

Mr. APRS himself, Bob Bruninga WB0APR. He bought the MIM from ... well whoever.
The last one I bought from him directly a few years ago.

Don

paul.verhage@... wrote:

How do we order MIMs now? Who is selling them?

Thanks,
Paul

Re: ATVQ Article

Hank Riley
 

I've emailed Mr. Harlan an article about GPSL.
Paul,

The GPSL piece you wrote up and posted was very good and
answered a lot of the basic questions.

Wondering if you have sent anything smaller to QST along
the way.

Hank

MIM?

paul.verhage@...
 

How do we order MIMs now? Who is selling them?

Thanks,
Paul

GPSL 2002... GPSL 2003

K. Mark Caviezel
 

All:
just now getting back on email after three weeks at
remote arctic outpost... congrats to all, looks like
it was a 100% super event!
As far as next year, Colorado is good, Kansas is good,
heck about anywhere is good. I was planning to
participate in GPSL 2002, but got opportunity to go to
the summer season of the Mars Society arctic research
station so I had to opt out. Maybe I could get some
Mars Society people to put up a balloon from the Devon
Island simultaneous with the main event.... with the
24 hour polar sunshine perhaps a floater could hang
around quite a while as they do at the south pole.
ahhh, just thoughts.... congrats again to all who
participated, sorry I had to miss it.

- KMC kc0jhq







__________________________________________________
Do You Yahoo!?
Yahoo! Health - Feel better, live better
http://health.yahoo.com

ATVQ Article

paul.verhage@...
 

I've emailed Mr. Harlan an article about GPSL. Can Mr. Harlan use
the photos we have on-line for ATV Quarterly? If there is a problem
with this, then I'll send him some hardcopies of mine.

Paul

Re: Articles?

Gene Harlan <atvq@...>
 

Thanks Paul. I will look forward to getting it!

Gene Harlan - WB9MMM
Harlan Technologies - publisher of
OSCAR Satellite Report - OSR@...
Amateur Television Quarterly - ATVQ@...
http://www.hampubs.com

----- Original Message -----
From: <paul.verhage@...>
To: <GPSL@...>
Sent: Friday, July 26, 2002 3:55 PM
Subject: Re: [GPSL] Articles?


Mr. Harlan, since I've not heard from anyone, I'm starting an article
on GPSL 2002 that will also mention the previous GPSLs. I'll try to
email it to you next week. I'll send a paper copy and photos by
mail.

Paul

Yes, do not forget "ATV magazine (whatever....)". The summer issue just
went
to press, and has a little that says "More coming....", so make sure we
get
it!

Thanks. Sounds like everyone had a great time.

Gene Harlan - WB9MMM
Harlan Technologies - publisher of
OSCAR Satellite Report - OSR@...
Amateur Television Quarterly - ATVQ@...
http://www.hampubs.com


----- Original Message -----
From: <paul.verhage@...>
To: <GPSL@...>
Sent: Thursday, July 18, 2002 1:00 PM
Subject: [GPSL] Articles?


Hank brings up a good point. Has anyone started writing
something about GPSL 2002? QST has asked me to send
something in, but that's no guarentee that it will be published.
Hanks has offered to write up something, how about everyone
else? Was something written for QRZ?

I'm wondering if you or anyone you may have selected will
be doing an official writeup of GPSL for dissemination
to the usual ham radio media suspects such as QST,
ARRL newsletter, CQ, CQ VHF, ATV magazine (whatever the
exact name is), etc.
Paul



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Re: QST Article, first draft

Michael L. Bogard <kd0fw@...>
 

You might want to thank your mother rather than take her. I will get my pictures posted at http://www.qsl.net/kd0fw If you are going to list any. 73's see and see you next year. Mike kd0fw
 

Dew Pt?

paul.verhage@...
 

I'm assuming the dew point at launch for GPSL must have been at
least in the mid 60's. Mark, is there a record kept of this
information? I've graphed the lapse rate as measured by my flight.
I'd like get the dew point and see if the atmosphere was stable and
until what altitudes.

Paul

Re: Articles?

paul.verhage@...
 

Mr. Harlan, since I've not heard from anyone, I'm starting an article
on GPSL 2002 that will also mention the previous GPSLs. I'll try to
email it to you next week. I'll send a paper copy and photos by
mail.

Paul

Yes, do not forget "ATV magazine (whatever....)". The summer issue just went
to press, and has a little that says "More coming....", so make sure we get
it!

Thanks. Sounds like everyone had a great time.

Gene Harlan - WB9MMM
Harlan Technologies - publisher of
OSCAR Satellite Report - OSR@...
Amateur Television Quarterly - ATVQ@...
http://www.hampubs.com


----- Original Message -----
From: <paul.verhage@...>
To: <GPSL@...>
Sent: Thursday, July 18, 2002 1:00 PM
Subject: [GPSL] Articles?


Hank brings up a good point. Has anyone started writing
something about GPSL 2002? QST has asked me to send
something in, but that's no guarentee that it will be published.
Hanks has offered to write up something, how about everyone
else? Was something written for QRZ?

I'm wondering if you or anyone you may have selected will
be doing an official writeup of GPSL for dissemination
to the usual ham radio media suspects such as QST,
ARRL newsletter, CQ, CQ VHF, ATV magazine (whatever the
exact name is), etc.
Paul



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Re: table of GPSL altitudes

Don Pfister <ka0jlf@...>
 

Actually it is still in the car from the launch, then photo shoot. I'll go get
it and get this checked off my "To Do" list. ;-)
It even made the trip to NE and back. ;-)

Back in a few,
Don (slow)

n1ltv wrote:

Don,

While you're around, inquiring minds would like to know
the weight of your GPSL HABITAT payload.

Surely you must be able to give a pretty good estimate
or actually drop it on a scale and weigh it. :)

Hank

Re: table of GPSL altitudes

Hank Riley
 

Don,

While you're around, inquiring minds would like to know
the weight of your GPSL HABITAT payload.

Surely you must be able to give a pretty good estimate
or actually drop it on a scale and weigh it. :)

Hank

Re: table of GPSL altitudes

Don Pfister <ka0jlf@...>
 

Yes, I meant to come back to this but have been sidetracked. One of the things I
have tried to do in the past was to capture the GPS data too. Mainly I was
interested in the Satelite data, number, signal strength, 2D/3D fix etc.

One of my main interests is that GPS info. With all the balloons, and the
inability to get my second beacon (GPS payload) running in time for the launch
(later I realized I hooked up the RD instead of the TD line) I didn't fly the
second beacon which would have sent the GPS data on a different band. Oh well
there will be next year for GPSL. And another HABITAT SkyLab flight probably
Aug. 3.

Sorry this was just a running off at the fingers (yet again, been a lot of that
from me lately).

Thanks,
Hank

n1ltv wrote:

Paul 26796 87900 (87913)

Paul (revised) 88200 (88163)

Do I think this reporting precision issue is
worthwhile to discuss?

Yes.

Reporting to a reasonable precision and no more
shows that the investigator is informed and aware
of the shortcomings of his data collection methods.

If this kind of data were ever to make it to an
engineering or scientific publication, the altitude
figures stated down to the foot, at least without
some qualification, would go out the window. They
just wouldn't get by the editor.

I know it's natural to use all the digits if you
have them, but it's not good practice because
the implied precision is bogus.

Hank


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--

[Signature File]
Name=Don Pfister KA0JLF
HABITAT SkyLab soon to add SeaLab (underwater robotics)
(High Altitude Basic Investigation Testing And Tracking)
Email=ka0jlf@... or ka0jlf@... or donp@...

http://habitat.netlab.org
http://www.kc.net/~dpfister - going away not sure when they will pull the plug
http://www.netlab.org/~donp
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http://home.kc.rr.com/cdpfister/
http://www.netlab.org:8888/ Visit the Lab in the Hobby wing. HABITAT being
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http://www.findu.com/cgi-bin/find.cgi?KA0JLF-9 van
http://www.findu.com/cgi-bin/find.cgi?KA0JLF-11 balloon

Re: table of GPSL altitudes

Hank Riley
 

Paul 26796 87900 (87913)

Paul (revised) 88200 (88163)


Do I think this reporting precision issue is
worthwhile to discuss?

Yes.

Reporting to a reasonable precision and no more
shows that the investigator is informed and aware
of the shortcomings of his data collection methods.

If this kind of data were ever to make it to an
engineering or scientific publication, the altitude
figures stated down to the foot, at least without
some qualification, would go out the window. They
just wouldn't get by the editor.

I know it's natural to use all the digits if you
have them, but it's not good practice because
the implied precision is bogus.

Hank

Re: table of GPSL altitudes

Hank Riley
 

where you list the groups and their
balloons, what about adding another column and listing
the altitudes? I think I saw a
chart of altitudes early after the flights.
Don,

I think you're remembering my post to TVNSP list (and maybe
a few other lists). It didn't go here, so here's it is
from July 7 (a few extra words added here and there). Since
this was written, Paul has a peak altitude revised slightly
upward by a couple hundred feet from what is shown below.

Hank
--------------------------------------------



July 7
------

meters feet

Paul 26796 87900 (87913)
Mike 26671 87500 (87503)
Don 26052 85500 (85472)
Mark* 24987 82000 (81978)
Zack 22167 72700 (72726)

*reported in feet and converted to meters

-------------------------------------------------------

This is what I get from using the igated data of the highest
*reported* altitudes. I've shown the feet converted from meters
rounded to hundreds of feet to set an example of showing data
to a reasonable degree of precision but no more (the
down-to-the-foot figures are in parentheses for those who
insist, but it's not a good practice).

Paul and Mike are already within a remarkably close 400 feet
of each other, and Paul's igated figures suggest that his peak
was almost caught perfectly by the timing of the packet
transmissions. Mike's figures don't indicate a favorable timing
(although it can't be ruled out), so to my way of thinking Mike's
balloon in actuality may have edged out Paul's by as much as
several hundred feet.

I offer these comments just to illustrate there is a certain
approximation involved in pegging a balloon's height without
more frequent measurements of the balloon's altitude and with
the limitations of GPS vertical accuracy. With this in mind, I
think it's best to consider it a tie between the first two in
the list.

The important point is that balloon altitudes by consumer GPS with
coarse reporting (every 60 or 30 seconds) are really only accurate
to within a hundred feet of absolute vertical position at best,
and likely err by as much as 500 feet in the direction of
underestimating altitude (because of the too infrequent measurement
cycle).

Hank

Re: QST Article, first draft

Don Pfister <ka0jlf@...>
 

Paul, I'm not sure this fits with your idea, where you list the groups and their
balloons, what about adding another column and listing the altitudes? I think I saw a
chart of altitudes early after the flights. Just a thought.

Web sites of interest, did you want to include EOSS?

Just as a point of interest (maybe just of interest to me), my 6M simplex repeater
capsule is the same one that flew in GPSL 2001. It was the same equipment, capsule -
even the batteries I think. ;-) Those that remember, last year, will know this is one
of capsules that were in a free fall for several thousand feet, when the capsules
separated from the parachute. Other than a scratch on the front of the simplex
repeater, there was no damage to this equipment.

Did you purposely leave out callsigns? Just a question.

Don

paul.verhage@... wrote:

Here's the first draft of the GPSL article for QST. Please look it
over for technical or historical errors or omissions. I still plan to
work on grammar, but if you see any glaring errors, please point
those out also.

I'll start putting something together for ATV Quarterly unless I hear
someone else is doing that.

Paul

Re: QST Article, first draft

Don Pfister <ka0jlf@...>
 

Nice article! I'm not sure but I think I almost had as many miles - going to and from
Manhattan/Herington/Home - as you did from Idaho. ;-)

paul.verhage@... wrote:

Here's the first draft of the GPSL article for QST. Please look it
over for technical or historical errors or omissions. I still plan to
work on grammar, but if you see any glaring errors, please point
those out also.

I'll start putting something together for ATV Quarterly unless I hear
someone else is doing that.

Paul