metric system newsgroup call for votes #1

"Robb McLeod" wrote in message
...
On Fri, 7 Nov 2003 22:52:32 -0800, "Tarver Engineering"
wrote:


"Robb McLeod" wrote in message
.. .
On Fri, 7 Nov 2003 08:58:24 -0800, "Tarver Engineering"
wrote:

And since nautical miles are a measurement system based on the earth,
they
work out real well for navigation.

That might have been true at one time but the Imperial system is now
entirely defined in terms of Metric units.

I fear you miss the entire point, nautical miles agree with latitude and
longitude.

snip of irrelevence

But the Earth isn't perfect sphere, nor is an arc minute the same in
a plane as a submarine. The natical mile was standardized to metric
because it was inconsistant depending on where you stood on the globe.

The nautical mile works fine inside the WGS-84 oblate speroid earth model.
Using meters is inapropriate for earth navigation.

Remulac is the only place meters make sense for navigation.

Robb McLeod wrote:

And since nautical miles are a measurement system based on the earth, they
work out real well for navigation.

That might have been true at one time but the Imperial system is now
entirely defined in terms of Metric units.

In Britain? I don't think we use Imperial in the U.S. though some of the units
are the same.

-- Charlie Springer

On Fri, 7 Nov 2003 08:58:24 -0800, "Tarver Engineering"
wrote:


"Mary Shafer" wrote in message
.. .
On Thu, 6 Nov 2003 21:22:47 GMT, lid (Goran Larsson)
wrote:

In article ,
Tarver Engineering wrote:

We sold a good number of metric altitude repeaters for Corporate
operation
in Eastern European airspace prior to the latest change. The air
traffic
control system was only capable of producing altitude assignments in
meters.

Yes, but are your *absolutely* sure that all "Western aircraft use
English units"?

For altitude and airspeed, they do. I'm absolutely sure. ICAO says
so.

And since nautical miles are a measurement system based on the earth, they
work out real well for navigation.

Not when your aviation charts are drawn to a metric scale.

You can use an ordinary ruler, not some expensive special purpose
plotter, on a sectional chart at 2 mm:1 km or a regional chart at 1
mm: 1 km.

Of course, the meter is also based on the Earth, like the nautical
mile and unlike the foot or the statute mile. Furthermore, a
centigrade or centigrad is to a kilometer as a minute of arc is to a
nautical mile. The grad is a non-SI unit of angle, but most
scientific calculators including the one which comes with Windows,
will do all the trig functions you'd need for navigation in those
units.

Of course, the relationship of either a nautical mile or a meter to
the Earth is only approximate. We don't have a perfectly spherical
Earth. If we did, or if they were based on the same midrange values,
we'd have 1 km = 0.54 nmi exactly, i.e. (1 km) (1 grad/100 km) (0.9
deg/grad) (60 nmi/deg) = 0.54 nmi.

--
Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/
"It's not the things you don't know
what gets you into trouble.

"It's the things you do know
that just ain't so."
Will Rogers

On Thu, 6 Nov 2003 08:29:11 -0800, "Tarver Engineering"
wrote:


"Paul Hirose" wrote in message
...
I'm posting this to a couple newsgroups where I remember discussions
drifting off-topic into units of measure.

There's a vote going now on creating a newsgroup about the metric
system:

The metric system is off topic for aviation newsgroups.

Certainly not.

Even if the new newsgroup was formed, we'll still have to keep posting
about it here to keep John Tarver straight.

I'm surprised you aren't pushing hard to get people to vote for this
new group.



Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

"Gene Nygaard" wrote in message
...
On Fri, 7 Nov 2003 08:58:24 -0800, "Tarver Engineering"
wrote:


"Mary Shafer" wrote in message
.. .
On Thu, 6 Nov 2003 21:22:47 GMT, lid (Goran Larsson)
wrote:

In article ,
Tarver Engineering wrote:

We sold a good number of metric altitude repeaters for Corporate
operation
in Eastern European airspace prior to the latest change. The air
traffic
control system was only capable of producing altitude assignments
in
meters.

Yes, but are your *absolutely* sure that all "Western aircraft use
English units"?

For altitude and airspeed, they do. I'm absolutely sure. ICAO says
so.

And since nautical miles are a measurement system based on the earth,
they
work out real well for navigation.

Not when your aviation charts are drawn to a metric scale.

How many meters are there between seconds of arc at the Equator?

He he ...

On Mon, 10 Nov 2003 13:47:26 -0800, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
.. .
On Fri, 7 Nov 2003 08:58:24 -0800, "Tarver Engineering"
wrote:


"Mary Shafer" wrote in message
.. .
On Thu, 6 Nov 2003 21:22:47 GMT, lid (Goran Larsson)
wrote:

In article ,
Tarver Engineering wrote:

We sold a good number of metric altitude repeaters for Corporate
operation
in Eastern European airspace prior to the latest change. The air
traffic
control system was only capable of producing altitude assignments
in
meters.

Yes, but are your *absolutely* sure that all "Western aircraft use
English units"?

For altitude and airspeed, they do. I'm absolutely sure. ICAO says
so.

And since nautical miles are a measurement system based on the earth,
they
work out real well for navigation.

Not when your aviation charts are drawn to a metric scale.

How many meters are there between seconds of arc at the Equator?

He he ...


That's nothing but a red herring, intended to draw attraction away
from the fact that the aeronautical charts use metric scales. More on
this below, more particularly dealing with military aviation than what
I mentioned last time.

Your one second of arc along the equator is 0.016670 nmi. Not very
handy units for those short distances.

Gentlemen of the jury, Chicolini here may look like an idiot,
and sound like an idiot, but don't let that fool you: He
really is an idiot.
Groucho Marx

One degree of arc on the Equator is 60.11 nmi.

Neither of them is particularly handy for calculations of precise
distances.

However, one degree of arc going from the Equator along a meridian,
using the normal geodetic latitudes, is only 59.70 nmi. That
unspherical Earth always throws a monkey wrench into these
calculations.

One milligrad of arc on the Equator is 0.10019 km.

One grad of arc on the Equator is 100.19 km.

Guess the kilometers are much easier, if you measure your angles in
those units.

One second of arc on the Equator is 30.92 m.

One degree of arc on the Equator is 111.3 km.

In this case, going from seconds to degrees is the same difficulty
whether you use nautical miles or meters, except that using nautical
miles you don't have the scaling that the metric prefixes give you,
for expressing the results in more reasonable numbers. There are no
generally used multiples and submultiples of a nautical mile. Sure,
some of the cable lengths were, but others were not, but they aren't
generally used. There aren't even a whole number of feet in a
nautical mile.

So let's get back to those charts.

When I was in the U.S. Army 30 years ago, our maps did have latitude
and longitude in grads as well as degrees. I'd bet that they still do
today.

However, more importantly, those same maps had grids lines every
kilometer, based on the UTM coodinate system. You can count squares
to get distance in kilometers in a N-S or E-W direction.

Now, with regard to military aviation. When the ground troops call in
for air support, they give their location and the enemy's location in
terms of those metric coordinates on that UTM grid.

Now if I'm a ground troop, I damn sure hope that the aviators are
using the same or similar maps, with a grid in kilometers and UTM
coordinates, so that they can find us based on the numbers we called
in.

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

"Gene Nygaard" wrote in message
news
On Mon, 10 Nov 2003 13:47:26 -0800, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
.. .
On Fri, 7 Nov 2003 08:58:24 -0800, "Tarver Engineering"
wrote:


"Mary Shafer" wrote in message
.. .
On Thu, 6 Nov 2003 21:22:47 GMT, lid (Goran Larsson)
wrote:

In article ,
Tarver Engineering wrote:

We sold a good number of metric altitude repeaters for Corporate
operation
in Eastern European airspace prior to the latest change. The
air traffic
control system was only capable of producing altitude
assignments in meters.

Yes, but are your *absolutely* sure that all "Western aircraft use
English units"?

For altitude and airspeed, they do. I'm absolutely sure. ICAO says
so.

And since nautical miles are a measurement system based on the earth,
they
work out real well for navigation.

Not when your aviation charts are drawn to a metric scale.

How many meters are there between seconds of arc at the Equator?

He he ...


That's nothing but a red herring, intended to draw attraction away
from the fact that the aeronautical charts use metric scales. More on
this below, more particularly dealing with military aviation than what
I mentioned last time.

Oh contrair, the entire rationalization for using base ten measurement
systems is their ease of use, be it making change, or work equations for
electromagnetic energy. In the case of Earth Navigation, and the
application of the WGS-84 oblate spheroid Earth model, the Nautical Mile
provides ease of use. Latitude and Longitude are laid out based on the
Nautical Mile and the lmeasure was in fact created specificly to address
Earth Surveying and property issues.

Your one second of arc along the equator is 0.016670 nmi. Not very
handy units for those short distances.

So then, a minute of arc is close to one.

"Gene Nygaard" wrote in message
...
On Thu, 6 Nov 2003 08:29:11 -0800, "Tarver Engineering"
wrote:


"Paul Hirose" wrote in message
...
I'm posting this to a couple newsgroups where I remember discussions
drifting off-topic into units of measure.

There's a vote going now on creating a newsgroup about the metric
system:

The metric system is off topic for aviation newsgroups.

Certainly not.

Even if the new newsgroup was formed, we'll still have to keep posting
about it here to keep John Tarver straight.

I'm surprised you aren't pushing hard to get people to vote for this
new group.

I have already done my part, through Congressman Klinger, to kill off
communisms units of measure, in the public square.

On Mon, 10 Nov 2003 14:50:57 -0800, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
news
On Mon, 10 Nov 2003 13:47:26 -0800, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
.. .
On Fri, 7 Nov 2003 08:58:24 -0800, "Tarver Engineering"
wrote:


"Mary Shafer" wrote in message
.. .
On Thu, 6 Nov 2003 21:22:47 GMT, lid (Goran Larsson)
wrote:

In article ,
Tarver Engineering wrote:

We sold a good number of metric altitude repeaters for Corporate
operation
in Eastern European airspace prior to the latest change. The
air traffic
control system was only capable of producing altitude
assignments in meters.

Yes, but are your *absolutely* sure that all "Western aircraft use
English units"?

For altitude and airspeed, they do. I'm absolutely sure. ICAO says
so.

And since nautical miles are a measurement system based on the earth,
they
work out real well for navigation.

Not when your aviation charts are drawn to a metric scale.

How many meters are there between seconds of arc at the Equator?

He he ...


That's nothing but a red herring, intended to draw attraction away
from the fact that the aeronautical charts use metric scales. More on
this below, more particularly dealing with military aviation than what
I mentioned last time.

Oh contrair,

Of course it was a red herring.

Anybody who notices that not only did you fail to address the metric
charts issue of my earlier message, but you have also now failed to
address the metric grid squares and UTM coordinates issue in military
aviation, can figure that out pretty darned easily.

Good grief! You've got to stop assuming that your own intelligence is
typical of this newsgroup. Most people (with a couple of notable
exceptions of course) following this thread are smarter than you are.

the entire rationalization for using base ten measurement
systems is their ease of use, be it making change, or work equations for
electromagnetic energy. In the case of Earth Navigation, and the
application of the WGS-84 oblate spheroid Earth model, the Nautical Mile

All the parameters for distances in WGS-84 are given in meters.
Nautical miles don't provide any advantage whatsoever in the type of
precision measurements for which this ellipsoid is used.

http://www.gmat.unsw.edu.au/snap/gps.../chap2/214.htm
http://home.online.no/~sigurdhu/Grid_1deg.htm
http://www.wgs84.com/

Example: One primary parameter is semimajor axis a = 6.378 137 Mm.
How many nautical miles is that?

Another primary parameter is Geocentric gravitational constant
(Mass of earth’s atmosphere included) GM = 398600.5 km^3 s^-2
What is that in nautical miles cubed per second squared?

There is no way whatsoever in which nautical miles provide any
advantage over meters for use with WGS-84.

provides ease of use. Latitude and Longitude are laid out based on the
Nautical Mile and the lmeasure was in fact created specificly to address
Earth Surveying and property issues.

Surveyors don't use nautical miles. They normally use meters;
sometimes in the U.S. they use the otherwise obsolete definition of a
foot as 1200/3937 m. No property disputes are ever determined on the
basis of nautical miles.

Your one second of arc along the equator is 0.016670 nmi. Not very
handy units for those short distances.

So then, a minute of arc is close to one.

Doesn't make it any easier if you are dealing with seconds of arc, the
units you yourself specified in your earlier message. Or with degrees
of arc; I can more easily multiply by 111 in my head than by 60.

How many minutes of arc is it from the airport at Antwerp, Belgium to
the airport at Christchurch, New Zealand, to the nearest minute of
arc? Do you ever see such distances expressed in minutes of arc?

How many nautical miles at sea level is it from the airport at
Antwerp, Belgium to the airport at Christchurch, New Zealand, to the
nearest nautical mile?

How much difference is there between those two numbers?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

"Gene Nygaard" wrote in message
news
On Mon, 10 Nov 2003 14:50:57 -0800, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
news
On Mon, 10 Nov 2003 13:47:26 -0800, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
.. .
On Fri, 7 Nov 2003 08:58:24 -0800, "Tarver Engineering"
wrote:


"Mary Shafer" wrote in message
.. .
On Thu, 6 Nov 2003 21:22:47 GMT, lid (Goran
Larsson)
wrote:

In article ,
Tarver Engineering wrote:

We sold a good number of metric altitude repeaters for
Corporate operation
in Eastern European airspace prior to the latest change. The
air traffic
control system was only capable of producing altitude
assignments in meters.

Yes, but are your *absolutely* sure that all "Western aircraft
use
English units"?

For altitude and airspeed, they do. I'm absolutely sure. ICAO
says
so.

And since nautical miles are a measurement system based on the
earth, they
work out real well for navigation.

Not when your aviation charts are drawn to a metric scale.

How many meters are there between seconds of arc at the Equator?

He he ...


That's nothing but a red herring, intended to draw attraction away
from the fact that the aeronautical charts use metric scales. More on
this below, more particularly dealing with military aviation than what
I mentioned last time.

Oh contrair,

Of course it was a red herring.

Just as it would be foolish to make electromagnetics calculations in feet,
it is silly to insist that meters are a realistic replacement for nautical
miles in navigation.

Anybody who notices that not only did you fail to address the metric
charts issue of my earlier message, but you have also now failed to
address the metric grid squares and UTM coordinates issue in military
aviation, can figure that out pretty darned easily.

We have had a series of experianced pilots here at ram indicate that the
English system is the one that works for navigation.

Good grief! You've got to stop assuming that your own intelligence is
typical of this newsgroup. Most people (with a couple of notable
exceptions of course) following this thread are smarter than you are.

That would be statistically extreemly unlikey.

the entire rationalization for using base ten measurement
systems is their ease of use, be it making change, or work equations for
electromagnetic energy. In the case of Earth Navigation, and the
application of the WGS-84 oblate spheroid Earth model, the Nautical Mile

All the parameters for distances in WGS-84 are given in meters.
Nautical miles don't provide any advantage whatsoever in the type of
precision measurements for which this ellipsoid is used.

Except in a prattical sense.

http://www.gmat.unsw.edu.au/snap/gps.../chap2/214.htm
http://home.online.no/~sigurdhu/Grid_1deg.htm
http://www.wgs84.com/

Example: One primary parameter is semimajor axis a = 6.378 137 Mm.
How many nautical miles is that?

How many meters between minutes at the equator?

One is a better number.