Coordinate system for flat rectangular surfaces

[gianman]

Hi all,

i would like to seasonally measure distances and areas inside a rectangle (200 cm x 150 cm) fixed with permanent marks in a vertical wall. The idea was to gain pictures and transfer them to ArcGIS desktop 10.2.

So i thought to create a new projected coordinate system with the reference scale based on the dimension of the rectangle side and the coordinates departing from the permanent vertices [i.e. vertices coordinates:  upper left (0 ; 150), upper right (200 ; 150), bottom left (0 ; 0), bottom right (200; 0)].

Platee Caree seems to be appropriate for the projection but i cannot find a solution for the coordinate system, would you be so kind to help me?

Thanks in advance,

Gianluca.

[MelitaKennedy]

So you'll convert the vertical surface into a horizontal one? If you have a known latitude-longitude of the rectangle, I would use that as the central meridian. Maybe even using stereographic or azimuthal equidistant instead, centered on the rectangle.

Melita

[gianman]

Thank You for the answer.

Exactly, converting the vertical surface into a horizontal one should be the aim. 

So the central meridian, that define the origin of the X coordinates,should be the longitude value of the rectangle vertex? Should i use some false easting and northing value furthermore a scale factor?

Thank you so much once again.

[MelitaKennedy]

You can reduce overall distortion by adding a scale factor, but your area of interest is small so it's really not needed. False easting and false northing parameters are used to keep all values positive or to differentiate between two similar projected coordinate systems that use different GCS, for instance.