Spot Heights in error

[tom]

My spot heights on right clicking appear to be hugely in error.
Have I missed something in setting up perhaps ??
Great bit of software Tim, this is my only problem thus far.

Cheers Tom.

[tim arnot]

What is "hugely in error"? Is this only at particular zoom levels? At particular locations?

Spot heights rely on the NGDC DEM files, which are 1km resolution.

[tom]

Hi Tim and thanks for responding.
I have not precisely recorded the orders of the inaccuracies, but as you have indicated the data is 1km resolution (of which I was not aware), this would probably account for most of the discrepancies I have witnessed.

One of note yesterday was of Mt Taranaki (Nth Island NZ) where the indicated map trig was of the order of 8200 odd feet, the highest spot height I could get by right clicking was around the 5000 feet mark....... but I guess even this is within the 1km resolution. 

So, ..... I will more accurately observe the orders of inaccuracy, but it seems the resolution of the data is the problem. Sorry to have bothered you - I am the wiser for it though.

Cheers ... Tom.

[tim arnot]

Yeah, mountain/volcano peaks like that would probably have to be hand edited into the data, and I don't know that they ever did that.