20 Direct Mecator Projections Flashcards
On a Direct Mercator chart, where is the Parallel of Origin?
At the Equator
On a Direct Mercator chart, what is the Constant of the Cone and what does this mean?
- Direct Mercator Chart, Constant of the Cone = 0
- Sin (Parallel of Origin) = 0
- There is no Chart Convergency
On a Direct Mercator chart, how are the parallels of latitude and meridians positioned relative to each other?
- Parallels of latitude are parallel BUT not equally spaced
- Meridians are parallel and are equally spaced (0 convergence)
How are Rhumb Lines and Great Circles depicted on a Direct Mercator chart?
- Rhumb Lines are straight lines
- Great Circles are curved lines, Convex to the nearest pole
On a Direct Mercator chart, what is the function of expansion?
- Expansion occurs as a function of the Secant to the latitude
- 1 / cos(lat)
On a Direct Mercator chart, what are the steps for calculating the Scale at a specific latitude, given the scale at a different latitude?
- Calculate the scale at the Equator by dividing by Cos(lat)
- Calculated the scale at the required latitude by taking the equator scale and multiplying it by Cos(lat)
On a Direct Mercator chart, where is the Chart Convergency equal to Earth Convergency?
At the Equator
