I need to convert grid co-ordinates from an old document to GPS co-ordinates that I can plot into Google Earth and ArcGIS. Here are the instructions:
'It was unfortunately not possible to produce maps using UTM co-ordinates. This problem was overcome by imposing a grid onto the map of Zimbabwe and digitising the site maps. The origin (00.00,00) of the grid was at 25 degrees, 05 minutes, 24 second east and 22 30 00 S. A point (80.00,00) along the X-axis was at 32 50 40 E and 22 25 40 S. One unit of distance on the grid represented 10 kilometres on real ground. The co-ordinates given in the following table represent the positions of the sites within this imposed grid.'
An example of a grid co-ordinate is: Name 2030 BD 1 Grid 60.21 24.78
Can anyone instruct me as to how I would go about doing this?