How Mercator Projection Works?

To keep longitude lines straight and maintain the 90° angle between the latitude and longitude lines, the Mercator projection uses varying distances between latitude lines away from the equator. As a result, the Earth's poles and landmasses closest to them are distorted.

How accurate is the Mercator projection?

Therefore, by construction, the Mercator projection is perfectly accurate, k = 1, along the equator and nowhere else. At a latitude of ±25° the value of sec φ is about 1.1 and therefore the projection may be deemed accurate to within 10% in a strip of width 50° centred on the equator.

How do you calculate Mercator projection?

The formula for Mercator's projection is T(ϕ, θ)=(θ, ln(|sec(ϕ) + tan(ϕ)|)). Of course, there are a huge number of map projections. Two more cylindrical projections are shown in figure 2.