^That is why the long term goal is to blend both technologies. You would have the computer based terrain displayed with the relativity short-range infrared mixed in with it. So during an IMC approach, you would see the synthetic terrain and runway 5 miles out, but as you approach 1/2 mile final, the deer picked up with the IR camera would be shown walking onto the runway.

Here is what Honeywell is doing

https://www.youtube.com/watch?v=JEvXr1nsJcE