GPS altitude again is close to actual

Suggest you go to the Garmin website, where you will find that the 430
and 530 ARE WAAS enabled. Even the cheap Garmin yellow etrex on the
shelves today (not the early ones) is WAAS enabled. It would in your
words be quite an omission for any NEW GPS unit to not be WAAS enabled,
though I certainly don't know that ALL of them are.

Mxsmanic wrote:
The GNS430 and GNS530 manuals I have in front of me say
nothing about WAAS, which would be quite an omission if they supported
it.

writes:

While correct for the case of LAAS and DGPS, this is not correct in the
case of WAAS.

It's true for WAAS, too. WAAS has only a few fixed reference points
and extrapolates for all other points.

--
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RomeoMike writes:

Suggest you go to the Garmin website, where you will find that the 430
and 530 ARE WAAS enabled.

I did, and I actually read what was on the page, where it is clearly
written that the 530 is WAAS-UPGRADEABLE. Obviously, if it is
upgradable, it doesn't use WAAS out of the box.

There is a version of the 530 that includes WAAS capability,
designated 530W. What that means, obviously, is that the base version
of the GNS 530 does not include WAAS.

It would in your
words be quite an omission for any NEW GPS unit to not be WAAS enabled,
though I certainly don't know that ALL of them are.

No, it would be an omission to provide WAAS capability and not mention
it in the manual. In the Garmin lexicon, "enabled" apparently means
"compatible with," but not "equipped with."

--
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mike regish writes:

I have actually had a hard time finding a cheap analog watch at times. I
always get the Indiglo face. I notice these days that they (analog) are
becoming more prevalent. But it only been the last year or 2.

Analog is probably more expensive to produce, and thus would be less
common among cheap watches.

I once had a watch with a LCD screen that showed simulated analog
hands, which was rather a combination of the best of both worlds. It
also had digits.

--
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Mxsmanic wrote:
writes:

While correct for the case of LAAS and DGPS, this is not correct in the
case of WAAS.

It's true for WAAS, too. WAAS has only a few fixed reference points
and extrapolates for all other points

You don't understand how WAAS works.

You stated:

" The further away you are from the surveyed reference
position used to generate the corrections, the more likely it is that
your position will be incorrect."

This is false. Being inside the reference network is all that matters,
proxitimity to a WRS does not matter.

Regards,
Jon

writes:

You don't understand how WAAS works.

Yes, I do. There are only 29 reference points in WAAS, including
Alaska. The corrections are completely accurate for these surveyed
reference points. For all other points, the corrections are
extrapolations.

This is different from LAAS and many DGPS systems, which use local
reference points to develop corrections for local receivers. No
significant extrapolation is required, so potential accuracy is
higher.

This is false. Being inside the reference network is all that matters,
proxitimity to a WRS does not matter.

No. The exact conditions of atmospheric disturbances and other
sources of inaccuracy cannot be fully predicted on the basis of
non-local references. The only truly accurate way to get this
information is to measure it at the point where it will be used.
However, this is very expensive, which is why WAAS was developed. It
trades a slight loss of accuracy for much lower cost.

--
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Mxsmanic wrote:
writes:

You don't understand how WAAS works.

Yes, I do. There are only 29 reference points in WAAS, including
Alaska. The corrections are completely accurate for these surveyed
reference points. For all other points, the corrections are
extrapolations.

You don't understand how WAAS works.

The corrections are to grid points based on observables from multiple
reference stations.

This is different from LAAS and many DGPS systems, which use local
reference points to develop corrections for local receivers. No
significant extrapolation is required, so potential accuracy is
higher.

This is false. Being inside the reference network is all that matters,
proxitimity to a WRS does not matter.

No. The exact conditions of atmospheric disturbances and other
sources of inaccuracy cannot be fully predicted on the basis of
non-local references. The only truly accurate way to get this
information is to measure it at the point where it will be used.
However, this is very expensive, which is why WAAS was developed. It
trades a slight loss of accuracy for much lower cost.

You don't understand how WAAS works.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Go to http://www.garmin.com/pressroom/aviation/110906.html and read "enabled." The new ones are enabled, the old ones upgradeable.



Mxsmanic wrote:
RomeoMike writes:

Suggest you go to the Garmin website, where you will find that the 430
and 530 ARE WAAS enabled.

I did, and I actually read what was on the page, where it is clearly
written that the 530 is WAAS-UPGRADEABLE. Obviously, if it is
upgradable, it doesn't use WAAS out of the box.

There is a version of the 530 that includes WAAS capability,
designated 530W. What that means, obviously, is that the base version
of the GNS 530 does not include WAAS.

It would in your
words be quite an omission for any NEW GPS unit to not be WAAS enabled,
though I certainly don't know that ALL of them are.

No, it would be an omission to provide WAAS capability and not mention
it in the manual. In the Garmin lexicon, "enabled" apparently means
"compatible with," but not "equipped with."

Look harder. Old ones are upgradeable, new ones are enabled, which means
enabled, not "equipped with."

Mxsmanic wrote:
RomeoMike writes:

Suggest you go to the Garmin website, where you will find that the 430
and 530 ARE WAAS enabled.

I did, and I actually read what was on the page, where it is clearly
written that the 530 is WAAS-UPGRADEABLE. Obviously, if it is
upgradable, it doesn't use WAAS out of the box.

There is a version of the 530 that includes WAAS capability,
designated 530W. What that means, obviously, is that the base version
of the GNS 530 does not include WAAS.

It would in your
words be quite an omission for any NEW GPS unit to not be WAAS enabled,
though I certainly don't know that ALL of them are.

No, it would be an omission to provide WAAS capability and not mention
it in the manual. In the Garmin lexicon, "enabled" apparently means
"compatible with," but not "equipped with."

Mxsmanic wrote:

writes:

You don't understand how WAAS works.

Yes, I do. There are only 29 reference points in WAAS, including
Alaska. The corrections are completely accurate for these surveyed
reference points. For all other points, the corrections are
extrapolations.

I suspect that Jon is far smarter on WAAS that either one of us Mx.

Ron Lee