patymurrieta

Question about OFFSET in Viewshed Analysis

Discussion created by patymurrieta on Mar 23, 2011
Latest reply on Mar 24, 2011 by patymurrieta
Hi, Im a bit confused about the offset concept in viewshed analysis and I want to know if somebody could help me to clarify it.

As far as I understand, the Offsets A and B, will basically add a vertical distance (height) either to the observer (offset A) or to the cells that are considered for visibility (offset B). However, somebody told me that they were actually controlling the view FROM or the view OF the observer and this got me confused.

My friend says that if for example, you do the viewsheds from a point file representing monuments and you assign a value of "0" to Offset A (as the height of the monument) and 1.70m (hypothetical human height) to Offset B, then the viewshed is a viewshed OF the monument. If you do it the other way around and put 5.50m (hypothetical height of the monument) in offset A and "0" in offset B then it will be the viewshed FROM the monument. 

Is this correct? And if it is, how it works???

Many thanks!!! :o

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