Flight Lessons

In article , "Paul J. Adam"
wrote:


That is not he fault of the GPS.

No, but it's a human mistake. It's a training issue to make sure that
when the GPS bings off a waypoint, you check a few landmarks to make
sure you're where the gadget says you should be. Currently, that doesn't
reliably happen because people have too much faith in the GPS.

the GPS acts up or the information it provides isn't used wisely.

That goes for anything and everything. Not just GPS.

Training is very important. To quote a friend, "You have to be smarter
than what you're working on."


The trouble is, GPS is too damn useful. Mike Marron wrote eloquently
about how a working GPS can replace most of your flight instruments...
as long as the GPS is working. But it's a low-powered signal from orbit
and it's easily jammed. GPS jamming isn't a feature of civilian life,
but it's a serious military problem. GPS offers much more than any other
navaid I've heard of, no wonder people turn to it first.

Oh Bo....ks.
GPS is easy to TRY to jam. Well known signal processing techniques are
all that's required to defeat jamming.

--
Harry Andreas
Engineering raconteur

"Harry Andreas" wrote in message
...
In article , "Paul J. Adam"
wrote:

The trouble is, GPS is too damn useful. Mike Marron wrote eloquently
about how a working GPS can replace most of your flight instruments...
as long as the GPS is working. But it's a low-powered signal from orbit
and it's easily jammed. GPS jamming isn't a feature of civilian life,
but it's a serious military problem. GPS offers much more than any other
navaid I've heard of, no wonder people turn to it first.

Oh Bo....ks.
GPS is easy to TRY to jam. Well known signal processing techniques are
all that's required to defeat jamming.

GPS is neither "easy to jam", or an apropriate "replacement" for existing
navigation systems. While Mike may have spread the snake oil in a manner
pleasing to our ground pounder lune Paul, an instrument cross check is a
necessity to maintain safe operations. Fused navigation sensors wisely take
this instrument cross check and make it part of the automation; but as Ed
points out, relying on only one instrument often results in errors.

John P. Tarver, MS/PE

In message ,
Harry Andreas writes
In article , "Paul J. Adam"
wrote:
The trouble is, GPS is too damn useful. Mike Marron wrote eloquently
about how a working GPS can replace most of your flight instruments...
as long as the GPS is working. But it's a low-powered signal from orbit
and it's easily jammed. GPS jamming isn't a feature of civilian life,
but it's a serious military problem. GPS offers much more than any other
navaid I've heard of, no wonder people turn to it first.

Oh Bo....ks.
GPS is easy to TRY to jam. Well known signal processing techniques are
all that's required to defeat jamming.

Harry, with GPS you're trying to not only detect a domestic light bulb
in low earth orbit, but to pull useful signal out of it. Doesn't take
much in-band noise to spoil that game, because there isn't much signal
there to start with. Directional aerials, parking beam nulls on the
jammers, games like that help but they also cost money and volume and
weight.


It's not the end of the world if the enemy whips out a few jammers, and
it's harder to do well than some would have you believe, but it's still
a genuine concern with fewer easy answers you suggest.

If there's a cheap, quick, easy and reliable magic bullet to make GPS
unjammable, then hasten down to your patent office at once.

--
When you have to kill a man, it costs nothing to be polite.
W S Churchill

Paul J. Adam MainBoxatjrwlynch[dot]demon{dot}co(.)uk

as long as the GPS is working. But it's a low-powered signal from orbit
and it's easily jammed.

How true is this, really? In an aircraft, you are between the ground
and the satellite. How does someone on the ground interfere with the
signal?

all the best -- Dan Ford
email: www.danford.net/letters.htm#9

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

Cub Driver wrote:

as long as the GPS is working. But it's a low-powered signal from orbit
and it's easily jammed.


How true is this, really? In an aircraft, you are between the ground
and the satellite. How does someone on the ground interfere with the
signal?


I don't believe that the antenna for the GPS is directional enough
that someone off axis couldn't put a signal into your system- after
all, a single antenna is used to pick up every satellite above the
horizon.

Mike Williamson

Hey Art, did you guys have a drift meter? Curious.

Navy P2Vs did in 50s -- along with Loran, radar, DR, celestial, and a few other
little helpers. Don't know about P3s, but I suspect they do. Handy. Don't
forget you can measure your ground speed with the things as well as drift.

Of course the navy tends to fly over water more than common sense should allow.

Quent

Quent

Subject: Flight Lessons
From: "Les Matheson"
Date: 8/7/03 3:17 PM Pacific Daylight Time
Hey Art, did you guys have a drift meter? Curious.

Les

No, but we had better. The Norden bombsight was the world's best driftmeter. If
you cranked out the drift by stopping the vertical hair, it would give you the
angle needed to correct the drift and track driift free. We call it a bomb
run. (grin). Can't beat that.

Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer

Same concept kill drift, compute crosswind, time, distance, heading for a DR
plot.

Les

"ArtKramr" wrote in message
...
Subject: Flight Lessons
From: "Les Matheson"
Date: 8/7/03 3:17 PM Pacific Daylight Time
Hey Art, did you guys have a drift meter? Curious.

Les

No, but we had better. The Norden bombsight was the world's best
driftmeter. If
you cranked out the drift by stopping the vertical hair, it would give you
the
angle needed to correct the drift and track driift free. We call it a
bomb
run. (grin). Can't beat that.

Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer

"Les Matheson" wrote in message
news:PMFYa.9988$ug.1099@lakeread01...
Same concept kill drift, compute crosswind, time, distance, heading for a
DR
plot.

Then lock up the AP to TRK.



Les

"ArtKramr" wrote in message
...
Subject: Flight Lessons
From: "Les Matheson"
Date: 8/7/03 3:17 PM Pacific Daylight Time
Hey Art, did you guys have a drift meter? Curious.

Les

No, but we had better. The Norden bombsight was the world's best
driftmeter. If
you cranked out the drift by stopping the vertical hair, it would give
you
the
angle needed to correct the drift and track driift free. We call it a
bomb
run. (grin). Can't beat that.

Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer

Subject: Flight Lessons
From: (OXMORON1)
Date: 8/8/03 10:10 AM Pacific Daylight Time
Message-id:

Les asked:
Hey Art, did you guys have a drift meter? Curious.

Add on question,
Anyone here ever fly a "Double Drift" leg after training? By 1965 it wasn't
even taught in USAF Nav course except as a two minute discussion in the basic
equipment ground course.
It was like the intro to loran "This is the APN.9 (?).and you'll never see
it
again, we use the XXX now" The first "Shakey that I got on had the old set
sigh and it didn't work double sigh

Oxmoron1


Taking an entire group of 56 Marauders through a double drift when you could
have gotten the same result in 15 seconds on the Norden, without even changing
course, didn't make much sense (sigh)

Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer