[mmaimcal] survey requirements

[Mark Holdaway]

> Topography should be given as grid of cells. Each cells is labeled by
> 'good' and 'bad'. The 'good' means that an antenna can be put at any
> point of the cell.  The 'bad' means that an antenna can not be put at
> any point of the cell.
> 

But the resolution to which you would concievably want to place antennas
is like half the dish diameter (ie, you want to make sure that tracks
are largely non-overlapping), and currently, the resolution of our
DEM is like 10m.  The resolution of the topography-based mask image
I gave to you is somewhat worse than that. 

> 
> Suppose we have the configuration we like. It is clear that we can
> shift and rotate the array saving all its property.

Rotation of the array conserves the general properties of the snapshot
coverage and snapshot beam, but not necesarily the long track beam and
coverage.

> Shifting and rotating we can minimizing number of antennas appeared at
> the 'bad' cells. That is what my task doing. I had the topography file
> with cell size 40x40 meters. Shifting and rotating I could minimize the
> number of antennas in the 'bad' cells to 2-5 of 36 antennas. At the
> second stage I removed the bad antennas from the 'bad' cells to the
> nearest 'good' cell and applyed my optimization algorithm with the
> topography constraint. It is rather simple because it is a question 
> of optimising position of a few antennas.
> 
> So we need to have a topography file at the form of 'bad'/'good' cells.
> The cells sizes should be 20-40m.
> 

Well, we can and should do 10m,  I think the 40m one I gave you was
basically for prototype calculations.


	-Mark