Topographic Normalization isn't going between -1 and 1, like expected

[jacobbieker]

Describe the bug
The topo normalization should be between -1 and 1 after subtracting the mean and dividing by the std dev, this normalization is computed across the whole of the topo data, so should hold true here I think. Instead the rane is seemingly -1 to 11ish

To Reproduce
Steps to reproduce the behavior:

1. Run the topo normalization test with prints

Expected behavior
A clear and concise description of what you expected to happen.

Additional context
Add any other context about the problem here.