PC said:
Frederick,
If we are going to help you, you need to answer our questions instead of
being evasive! I asked three questions and you did not answer any of them.
Are these statements fair to say ?
If easting Point 1 < easting Point 2 AND northing Point 1 = northing Point
2, you have moved due West?
If northing Point 1 < northing Point 2 AND easting Point 1 = easting Point
2, you have moved due North?
Another question ---
Is moving 10 units easting the same distance as moving 10 units northing?
--
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Below is the text from the web page on UTM. I don't know what Im
talking about, but here is
my take on it.
1. The Central Meridian is assigned a value of 500,000 and is the
vertical center of each zone.
2. In the northern hemisphere the value at the equator is 10,007,543 and
the North pole is 0.
3. In the southern hemisphere the value at the equator is 10,007,543 and
th South pole is 0.
Not sure about this. It could be Sequator 0 and south pole 10,007,543.
For the logic of point 1 less then or greater than point 2, the south
pole should be 0.
So if I'm half way between the equator and the north pole, my northing
is 4,746,040 N.
From my current location, say 328204 E, and I move East my new Easting
is greater.
If I move West my Easting is smaller.
West-------------------Central Meridian-------------------------East
0-----------------------------500,000----------------------------1,000,000
Not sure if the east number is 1,000,000
So, the answer to your 1st two questions is yes. The answer for the
units, as I see it is yes,
a unit is 1 meter. Those 10 units as a square would be 100 square meters.
Text fom th eWeb page about UTM.
The zones are then further subdivided into an eastern and western half
by drawing a line, representing a transverse mercator projection, down
the middle of the zone. This line is known as the 'central meridian' and
is the only line within the zone that can be drawn between the poles and
be perpendicular to the equator (in other words, it is the new 'equator'
for the projection and suffers the least amount of distortion). For
this reason, vertical grid lines in the UTM system are oriented parallel
to the central meridian. The central meridian is also used in setting
up the origin for the grid system.
Any point can then be described by its distance east of the origin (its
'easting' value). By definition the Central Meridian is assigned a
false easting of 500,000 meters. Any easting value greater than 500,000
meters indicates a point east of the central meridian. Any easting value
less than 500,000 meters indicates a point west of the central meridian.
Distances (and locations) in the UTM system are measured in meters, and
each UTM zone has its own origin for east-west measurements.
To eliminate the necessity for using negative numbers to describe a
location, the east-west origin is placed 500,000 meters west of the
central meridian. This is referred to as the zone's 'false origin'. The
zone doesn't extend all the way to the false origin.
The origin for north-south values depends on whether you are in the
northern or southern hemisphere. In the northern hemisphere, the origin
is the equator and all distances north (or 'northings') are measured
from the equator. In the southern hemisphere the origin is the south
pole and all northings are measured from there. Once again, having
separate origins for the northern and southern hemispheres eliminates
the need for any negative values. The average circumference of the
earth is 40,030,173 meters, meaning that there are 10,007,543 meters of
northing in each hemisphere.
UTM coordinates are typically given with the zone first, then the
easting, then the northing. So, in UTM coordinates, Red Hill is located
in zone twelve at 328204 E (easting), 4746040 N (northing). Based on
this, you know that you are west of the central meridian in zone twelve
and just under halfway between the equator and the north pole. The UTM
system may seem a bit confusing at first, mostly because many people
have never heard of it, let alone used it. Once you've used it for a
little while, however, it becomes an extremely fast and efficient means
of finding exact locations and approximating locations on a map.
Like I said, this is my take on the subject, but I really don't know
what I talking about.
Ron
