What is the difference between the mercator and transverse mercator projection

To eliminate negative coordinates, the coordinate system alters the coordinate values at the origin of the south zones. The value given to the central meridian is the false easting, and the value assigned to the equator is the false northing. A false easting of , meters is applied. A north zone has a false northing of zero, while a south zone has a false northing of 10,, meters.

The State Plane Coordinate System is not a projection. It is a coordinate system designed for the large-scale mapping in the United States. Three conformal projections were chosen for that purpose. Among them, the transverse Mercator is used for zones that are longer north-south.

Both 3- and 6-degree-wide zones exist. Some parameter values, like the scale factor and sometimes the false easting, differ from UTM.

Dozier, J. Snyder, J. Map Projections: A Working Manual. Because of this, map scale varies within projected plane UTM coordinate system grids. The distortion ellipses plotted in red help us visualize the pattern of scale distortion associated with a particular projection. Had no distortion occurred in the process of projecting the map shown in Figure 2. As you can see, the ellipses centered within the highlighted UTM zone are all the same size and shape.

Away from the highlighted zone, the ellipses steadily increase in size, although their shapes remain uniformly circular.

This pattern indicates that scale distortion is minimal within Zone 30, and that map scale increases away from that zone. Furthermore, the ellipses reveal that the character of distortion associated with this projection is that shapes of features as they appear on a globe are preserved while their relative sizes are distorted. Map projections that preserve shape by sacrificing the fidelity of sizes are called conformal projections.

The plane coordinate systems used most widely in the U. The Transverse Mercator projection illustrated above Figure 2. Fifty-nine variations on this projection are used to minimize distortion in the other 59 UTM zones.

In every case, distortion is no greater than 1 part in 1, The animation linked to the illustration in Figure 2. Each zone is based upon a unique Transverse Mercator map projection that minimizes distortion within that zone. Zones are numbered 1 to 60 eastward from the international date line. The USGS uses the Transverse Mercator in their , to , quadrangle maps because they can be joined at their edges.

Further to this, State Plane Coordinate Systems use a Transverse Mercator when its orientation is a north-east extent. The Transverse Mercator m projection is conformal with shapes being true in small areas. While the equator is a straight line, other parallels are complex curves concave toward nearest pole.

The Miller Projection was developed by O. Miller in using a cylinder projection developable surface tangent at the Equator. The Miller map projection is very similar to Mercator, but straight lines are not Rhumb Lines. Poles are distorted without the same degree of bulging in the polar regions as the Mercator projection.

This is why cartographers often use azimuthal projections for the polar regions. However, the Miller Projection increases the distortion of distances, areas, and shapes that occur at high latitudes. The oldest known record of this projection is from Ptolemy in about AD.

However it is believed that this projection was well known long before that time — probably as far back as the 2nd century BC. Today, this is probably one of the most widely used Azimuthal projections. It is most commonly used over Polar areas, but can be used for small scale maps of continents such as Australia. The great attraction of the projection is that the Earth appears as if viewed form space or a globe.

This is a conformal projection in that shapes are well preserved over the map, although extreme distortions do occur towards the edge of the map. One interesting feature of the Stereographic projection is that any straight line which runs through the centre point is a Great Circle. The advantage of this is that for a place of interest e. Canberra, the capital city of Australia a map which uses the Stereographic projection and is centred on that place of interest true distances can be calculated to other places of interest e.

His mathematics was considered revolutionary for its time and is still considered important today. Today the Lambert Conformal Conic projection has become a standard projection for mapping large areas small scale in the mid-latitudes — such as USA, Europe and Australia. It has also become particularly popular with aeronautical charts such as the , scale World Aeronautical Charts map series. This projection commonly used two Standard Parallels lines of latitudes which are unevenly spaced concentric circles.

The projection is conformal in that shapes are well preserved for a considerable extent near to the Standard Parallels. For world maps the shapes are extremely distorted away from Standard Parallels.

Distances are only true along the Standard Parallels. Across the whole map directions are generally true. One of the most famous map projections is the Mercator, created by a Flemish cartographer and geographer, Geradus Mercator in It became the standard map projection for nautical purposes because of its ability to represent lines of constant true direction.

Constant true direction means that the straight line connecting any two points on the map is the same direction that a compass would show. In an era of sailing ships and navigation based on direction only, this was a vitally important feature of this projection.