Setting altimeters with no radio

Newps writes:

A satellite is a satellite. The information that spews forth from that
satellite is just information that my receiver makes use of.

Hardly. GPS satellites are very special, as are the transmissions
they produce. WAAS satellites are just commercial satellites
transmitting fairly ordinary information in fairly ordinary ways.

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

mike regish writes:

Wow. That's news. What the hell are all these GPS companies trying to sell
us?

Receivers that combine several different technologies, one of which is
GPS. Moving maps aren't part of GPS, either, and neither are
autopilots.

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

DR writes:

What do you think the WAAS is "augmenting"?

If it were part of GPS, it couldn't augment itself. QED.

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

DR wrote:
On my 12 channel boat GPS I see a
HDOP of ~1m these days.

HDOP is unitless.

Ron Lee

"Jim Macklin" wrote in message
...
The word SHALL has a legal meaning...
(1) On a magnetic course of zero degrees through 179
degrees, any odd thousand foot MSL altitude +500 feet (such
as 3,500, 5,500, or 7,500); or

You got me. I'll confess. I forgot that those were actually regulations. I
fly them. I just forgot they were regs.

-------------------------------
Travis
Lake N3094P
PWK

"Mxsmanic" wrote in message
...
It does indeed measure angles, rest assured. Of course, it does a lot
more than that.

It is complex. But it's not triangulation. If it were, you would only need
two well-placed satellites to fix a position. You need three satellites to
fix a 2-D position and four to fix a 3-D.

-------------------------------
Travis
Lake N3094P
PWK

"Mxsmanic" wrote in message
...
Newps writes:

Wrong, as usual. It's all part of the same system.

That's not the way the DoD looks at it, and they built GPS.


Excuse me? The DoD didn't build all of the GPS receivers out there either.
Are they not part of the GPS system by your definition? The only thing the
DoD built (or more accurately, bought) is the license to the technology and
to the satellites. The also bought military spec receivers. The rest is
commercial, free market use of the broadcast signals. WAAS included.

-------------------------------
Travis
Lake N3094P
PWK

"Stefan" wrote in message
. ..
Travis Marlatte schrieb:
VFR, it doesn't really matter, does it?

I've always thought that airspace boundaries are to be respected by VFR
traffic, too.

Stefan

I agree that there are many reasons why I need to know my pressure
compensated altitude to avoid busting airspace or illegally flying to close
to person or property.

The discussion was about the life-saving necessity of an accurate altitude
instrument. MX was claiming that GPS is inaccurate enough to kill you. I
presume that that can only happen in one of two ways 1) I fly into the
ground believing my inaccurate intrument or 2) I fly at an altitude
different than the regulated VFR cruise altitudes and run into another
plane.

I think both are highly unlikely in VFR conditions no matter how inaccurate
the instrument.


-------------------------------
Travis
Lake N3094P
PWK

Regardless, in this case GPS derived altitude was quite good.

Ron Lee



One of the challenges with GPS fixes (both horizontal and vertical) is that
there is a statistical distribution of the error. Most receivers advertise
being within 15' laterally, 90% of the time. It's that other 10% that you
gotta worry about.

Surveyors improve their accuracy by leaving the GPS receiver stationary to
get a statistical sampling that can reveal the true position.

--
-------------------------------
Travis
Lake N3094P
PWK

Those are receivers, not the GPS. WAAS is completely independent of
GPS.



It's integral to the system. You receive WAAS from a satellite.

Typical of the troll's pattern. (not you newps - I have the real troll blocked)
Argue with what we know to be true.

I don't understand why people continue with him.
--
Jim in NC