I am trying to find which areas a camera can view from a certain point inside a given circle (known radius).
I tried to use the Viewshed tool Arcmap provides in order to do that. I read here that I have to use additional options in order to define the radius and the offset.
So I created a point feature class as my camera's position. I chose the WGS_1984_Web_Mercator_Auxiliary_Sphere projection in order to have units in meters and I add one point as my observer point (camera). Then in the attribute table I added two extra fields OFFSETA and RADIUS2 and set the values to 1.5 and 1500. I suppose that the units is in meters because of my projection selection. Am I right?
The DEM file I use is in the WGS84 Geographic Coordinate System meaning that its units is in decimal degrees. Does this make any difference? I mean does the tool transform meters to decimal degrees or the opposite automatically?
Then I used Viewshed tool. The result had ignored the radius value and in the output raster there were areas away from 1500m. I tried using different values for RADIUS2 but nothing changed. I also tried it without the OFFSETA field supposing that there was something wrong with this value but again nothing changed my output.
Am I missing something?
I am using ArcGIS Desktop 10.
I think I dont insert the types of optional values correct. Should they be integers, doubles or something else?Maybe that is why the tool ingores my values and uses the default ones.
أكثر...
I tried to use the Viewshed tool Arcmap provides in order to do that. I read here that I have to use additional options in order to define the radius and the offset.
So I created a point feature class as my camera's position. I chose the WGS_1984_Web_Mercator_Auxiliary_Sphere projection in order to have units in meters and I add one point as my observer point (camera). Then in the attribute table I added two extra fields OFFSETA and RADIUS2 and set the values to 1.5 and 1500. I suppose that the units is in meters because of my projection selection. Am I right?
The DEM file I use is in the WGS84 Geographic Coordinate System meaning that its units is in decimal degrees. Does this make any difference? I mean does the tool transform meters to decimal degrees or the opposite automatically?
Then I used Viewshed tool. The result had ignored the radius value and in the output raster there were areas away from 1500m. I tried using different values for RADIUS2 but nothing changed. I also tried it without the OFFSETA field supposing that there was something wrong with this value but again nothing changed my output.
Am I missing something?
I am using ArcGIS Desktop 10.
I think I dont insert the types of optional values correct. Should they be integers, doubles or something else?Maybe that is why the tool ingores my values and uses the default ones.
أكثر...