[asheshouse]

There are various ways to do this but here is one suggestion by cloning FabianFreds ground plates.
I assume that you have UI 1.1 installed.

In the MODS folder find Objects_ffb and in the airfields subfolder find the Ankor2 object folder.
This is a 1kmx1km plate With texture SkinHi.tga applied.
Copy the folder

Make a new mod folder and copy the contents of the ffb folder into it

root/MODS/NewFieldPlates/3do/airfield/Ankor2

Change the folder name to something suitable

root/MODS/NewGroundPlates/3do/airfield/NewFieldPlate1

create more folders with duplicate contents

root/MODS/NewGroundPlates/3do/airfield/NewFieldPlate2
root/MODS/NewGroundPlates/3do/airfield/NewFieldPlate3
etc

Now add text to your static.ini

//===========================================================================
[***]
Title New Field Plate
//===========================================================================
[buildings.Plate$NewFieldPlate1]
Title NewFieldPlate1
Mesh 3do/airfield/NewFieldPlate1/mono.sim

[buildings.Plate$NewFieldPlate2]
Title NewFieldPlate2
Mesh 3do/airfield/NewFieldPlate2/mono.sim

[buildings.Plate$NewFieldPlate3]
Title NewFieldPlate3
Mesh 3do/airfield/NewFieldPlate3/mono.sim


Now if start the game and go to FMB in Map Editor mode
and pull down the objects menu you will see that you have three new objects under the "New Field Plate" heading

All of the objects will be the same as FFB's Ankor2 object

You now need a graphics editor which will allow you to edit alpha channels.
Photoshop or Gimp or similar

Use the alpha mask to make parts of the texture transparent
Edit the RGB colours normally to change the textures.

Now take your satellite image and adjust the image size so that 1024pixels equals 1 km.
Cut it into kilometre squares to make SkinHi.tga textures for each plate.
Use the alpha mask to trim the edges to suitable boundary lines.

If 1km sq plates are too big then edit body.msh to make it smaller.

This would be for a 0.5km square

[Vertices_Frame0]
250.0 250.0 0.0 0.0 0.0 1.0
-250.0 250.0 0.0 0.0 0.0 1.0
-250.0 -250.0 0.0 0.0 0.0 1.0
250.0 -250.0 0.0 0.0 0.0 1.0
//4 verts

I think you would reduce the texture to 512x512 pixels for this.