Aerial photogrammetry involves a series of transformations to convert 2D image measurements into real-world ground coordinates. 

a)     Name the four main coordinate systems used in this process. For each, specify the typical units and what the origin represents.    (8)

b)     Summarise the steps to convert scanned photo pixel coordinates to ground coordinates.    (4)                   

c)     Explain the key difference in the implementation of this workflow when applied to digital aerial imagery (DAI) compared to digital derived image (DDI, also referred to as an analogue image).    (3)