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Old 19-04-2012, 19:36   #16
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Re: IPad GPS is off 100 ft

iNavX reports the accuracy of the GPS in the "HPE:" field in the Instruments banner and view. Typically the amount of Horizontal Position Error will be under 20'. So I would check that first. iNavX, Navionics, MotionX, etc. all use "Location Services" to plot their position. So if one app has any plotting error, the others most likely will.
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Old 19-04-2012, 19:52   #17
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Originally Posted by GPSNavX
iNavX reports the accuracy of the GPS in the "HPE:" field in the Instruments banner and view. Typically the amount of Horizontal Position Error will be under 20'. So I would check that first. iNavX, Navionics, MotionX, etc. all use "Location Services" to plot their position. So if one app has any plotting error, the others most likely will also.
The motionx app also reports that position will be accurate from 30-300 feet.

I rarely see an error greater than 20 but it could be worse at times.

I wonder if different ipad covers affect reception? Shouldn't but could, I am guessing...
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Old 19-04-2012, 19:54   #18
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Re: IPad GPS is off 100 ft

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I was wondering that as well...thanks Nick.
I just took my iPad 2 outside and got an accuracy of 16 feet. This is OUTSIDE WAAS area, so just plain old GPS accuracy. Better than can be expected because I always learned that was 15 meters, i.e. 50 feet.

ciao!
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Old 19-04-2012, 20:02   #19
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I'm wondering if the iPad does not do WAAS? Does anyone know?

I know it does triangulation with cell towers to help its accuracy. Perhaps with no cell towers within range and no WAAS, it has no sort of differential and therefore a less than decent position? Opinions?
I believe it does not as the aviation sites all talk about using an external aviation grade gps for position accuracy.

http://www.foreflight.com/support/gps

This one is interesting - scroll down to FlyWi article. It is a waas gps that can provide services for up to 4 iOS devices at once - that's cool... (but pricey)

http://www.flightguide.com/flight_guide_iefb.html#flywi
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Old 19-04-2012, 20:04   #20
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One point to make, I have two iPads. One the GPS is off on it and the other, GPS is accurate. So it's not a government problem or software problem.
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Old 19-04-2012, 20:07   #21
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Re: IPad GPS is off 100 ft

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Yes, scary




Nick.

Hey Nick, Can you tell me where I can get one of these - looks like a perfect iCrew to me....

Steve
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Old 19-04-2012, 20:21   #22
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Re: IPad GPS is off 100 ft

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Hey Nick, Can you tell me where I can get one of these - looks like a perfect iCrew to me....

Steve
Be warned that they don't come like that initially...



cheers,
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Old 19-04-2012, 21:15   #23
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Re: IPad GPS is off 100 ft

You are right & I take your warning - that is scary!
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Old 19-04-2012, 22:05   #24
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Re: IPad GPS is off 100 ft

I think the iPad gps accuracy is not as good as the dedicated Gps units, particularly when the signal strength is low. If I watch the plot of position when a anchor a handheld Garman has a much tighter plot pattern.
The iPad is still great as a back up. The Navionics charts are a bargin.
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Old 19-04-2012, 22:29   #25
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Re: IPad GPS is off 100 ft

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Maybe I am old school but when conditions are visual and landmarks are available I navigate with coastal charts, eyeballs and bearing compass and use gps as a reference/backup.
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Old 20-04-2012, 06:54   #26
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Re: IPad GPS is off 100 ft

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iNavX reports the accuracy of the GPS in the "HPE:" field in the Instruments banner and view. Typically the amount of Horizontal Position Error will be under 20'. So I would check that first. iNavX, Navionics, MotionX, etc. all use "Location Services" to plot their position. So if one app has any plotting error, the others most likely will.
I checked the HPE field and it's bouncing from 98' to 164' which is about what the map is showing. Wonder what my solution is? My other iPad is showing 20' in the same spot.

I try to never cruise in bad weather, but an accurate GPS aids me in the Bahamas going thru narrow cuts. I'm allways on the flybridge watching for shallow water, but still keeping an eye on the chart plotter . Cannot do that any more with this iPad.
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Old 20-04-2012, 07:34   #27
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Re: IPad GPS is off 100 ft

Cause unknown, but the lesson sure should be clear!
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Old 20-04-2012, 07:55   #28
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Re: IPad GPS is off 100 ft

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I checked the HPE field and it's bouncing from 98' to 164' which is about what the map is showing. Wonder what my solution is? My other iPad is showing 20' in the same spot.

I try to never cruise in bad weather, but an accurate GPS aids me in the Bahamas going thru narrow cuts. I'm allways on the flybridge watching for shallow water, but still keeping an eye on the chart plotter . Cannot do that any more with this iPad.
Use the Mark I eyeball. I never trust a chartplotter in a tight situation.
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Old 20-04-2012, 15:02   #29
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I just got my GPS to show me setting at my dock.
I was talking to a friend who has an aircraft iPad business. He said when he has a problem with gps accuracy, he shuts the iPad off and reboots it.
I did this and sure enough my boat came off the land behind the marina and is setting at my dock.

He said h e uses the remote gps150 when he flys his plane. Sometimes the internal iPad gps does not pick up a good signal in his plane.
Gee
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Old 20-04-2012, 23:18   #30
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I just got my GPS to show me setting at my dock.
I was talking to a friend who has an aircraft iPad business. He said when he has a problem with gps accuracy, he shuts the iPad off and reboots it.
I did this and sure enough my boat came off the land behind the marina and is setting at my dock.

He said h e uses the remote gps150 when he flys his plane. Sometimes the internal iPad gps does not pick up a good signal in his plane.
Gee
That is how I am set up. I bought the original iPad with no 3g never consideing that gps didnt come with it. Doh!

I bought both the bad elf and the gpsx150. Both are good in ways. I like the gpsx150 bluetooth as I can set the puck outside.

I will still get the 3g next time but for those without either of these gos is a dream.
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