GPS 96C

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Lesser_spotted_owl
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GPS 96C

Postby Lesser_spotted_owl » Mon Jun 30, 2008 9:03 am

While i was out flying yesterday i noticed the GPS doing something strange.

Level flight at 6000 ft, the alt on the GPS would match the Altimeter, but then suddenly jump up by +-500ft, then return to normal, and then do it again

Any ideas on why this would be, anybody else experienced this?
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Morph
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Re: GPS 96C

Postby Morph » Mon Jun 30, 2008 9:22 am

GPS calculates what it thinks is the aititude based on geometric calculations and connection to a minimum of 3 to 4 satelites. If it temporarily loses connection then reconnects it frantically recalculates again.

I have found from experience if you head south east your body shields the GPS from some of the satelites. (they are mainly in the north). I had a Magellan 315 at the time and it would then loose on axis and start hunting. A real pain
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Re: GPS 96C

Postby Lesser_spotted_owl » Mon Jun 30, 2008 9:39 am

Thanks Morph,

That makes sense, thinking about it now i was heading South/South east when i saw it doing it's little trick, also had it mounted on the PAX right hand foot rest. i must say i didn't pay any more attention to the Alt later on in the flight as i was watching it on the Skydat, i wasn't using it to navigate, i was only really using it to see the track afterwards and the occasional ground speed check. will see if it does it again next time and take note of the headings.

Big head wind, making 40kts on the way to the Vaal and 65kts on the way back, motoring along just nicely, smooth though, no bumps at all.

By the way, was in Cape Town last week, Wednesday looked just about the most perfect weather for flying, nice and clear, looked like a Joburg winter morning. :mrgreen:
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Re: GPS 96C

Postby Dre'man55 » Mon Jun 30, 2008 12:20 pm

If flying between Circus and Vaal I also found GPS acts strange along with the radio near the tal radio masts.
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Re: GPS 96C

Postby Lesser_spotted_owl » Mon Jun 30, 2008 12:27 pm

Yep, i'd forgotten about the radio masts,

Get serious bleed over the radio, can switch it off and still listen to the Moz radio station, comes over the intercom, really loud too
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Re: GPS 96C

Postby Morph » Mon Jun 30, 2008 2:47 pm

Lesser_spotted_owl wrote:By the way, was in Cape Town last week, Wednesday looked just about the most perfect weather for flying, nice and clear, looked like a Joburg winter morning. :mrgreen:
And you didn't look us up because :shock: :wink: :lol: 8)
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Re: GPS 96C

Postby Grumpy » Mon Jun 30, 2008 2:58 pm

Morph, do you think the 'owl' might have been afraid at all?
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Re: GPS 96C

Postby Morph » Mon Jun 30, 2008 3:03 pm

:?: :lol:
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Re: GPS 96C

Postby Lesser_spotted_owl » Mon Jun 30, 2008 3:12 pm

Ha, the Owl afraid??

The Owl gives fear turbo wedgies and then pours ice cubes down his pants ##

On a more serious note, I should be there again on the week of the 14th, will look you fellows up, wheres good to go drinking down there?

(^^)
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Re: GPS 96C

Postby Morph » Mon Jun 30, 2008 3:59 pm

In which area are you staying? We will find you (^^)
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Re: GPS 96C

Postby Lesser_spotted_owl » Mon Jun 30, 2008 4:04 pm

Probably Century city, nice and convenient.

Usually spend most of my time up at Ceres when i am in the Cape, but this time working in Parow so not too far from work, will give you a heads up when I am on my way down there. can have some (^^) vhpy
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Re: GPS 96C

Postby Morph » Mon Jun 30, 2008 4:07 pm

Cool, I work in Century City. There are quite a number of places near by including Morning Star, and Blouberg (Blue Peter, Doodles, News Cafe......)
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Re: GPS 96C

Postby Dre'man55 » Mon Jun 30, 2008 4:27 pm

Lesser_spotted_owl wrote:Ha, the Owl afraid??

The Owl gives fear turbo wedgies and then pours ice cubes down his pants ##

On a more serious note, I should be there again on the week of the 14th, will look you fellows up, wheres good to go drinking down there?

(^^)

mmmm but doesn't want to fly in the morning coz its cold????????
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Re: GPS 96C

Postby Lesser_spotted_owl » Tue Jul 01, 2008 8:49 am

Dre'man55 wrote:
Lesser_spotted_owl wrote:Ha, the Owl afraid??

The Owl gives fear turbo wedgies and then pours ice cubes down his pants ##

On a more serious note, I should be there again on the week of the 14th, will look you fellows up, wheres good to go drinking down there?

(^^)

mmmm but doesn't want to fly in the morning coz its cold????????
Now Now, i never said won't, In fact, wx permitting, i think i'll go and turn some fuel into noise on Sunday morning, it's only the feet that get cold, just need to wear another pair of socks :lol:

You keen Dre'man?
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Re: GPS 96C

Postby Dre'man55 » Tue Jul 01, 2008 1:14 pm

Lesser_spotted_owl wrote:
Dre'man55 wrote:
Lesser_spotted_owl wrote:Ha, the Owl afraid??

The Owl gives fear turbo wedgies and then pours ice cubes down his pants ##

On a more serious note, I should be there again on the week of the 14th, will look you fellows up, wheres good to go drinking down there?

(^^)

mmmm but doesn't want to fly in the morning coz its cold????????
Now Now, i never said won't, In fact, wx permitting, i think i'll go and turn some fuel into noise on Sunday morning, it's only the feet that get cold, just need to wear another pair of socks :lol:

You keen Dre'man?
I would love to but are doing the family quad day thing so heading out to Rhino park. Any other day I'm in.
Must get airborne again
Andre'
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