Viewshed problems
jdou
Global Mapper User
Hi,
I have just installed software to get an insight of a potential viewshed of a marine based windfarms around a Island. I am using an ASCI file as the map for the Island, however I am not getting any viewshed whenever I place any structure a few meters away from the coast. However, this is working fine when I place a structure in a bay. I tried placing structures on a sister Island but the effect was almost invisible on the other land since the view spread across the water. Is there a way how one could go around this issue? Any help would be appreciated.
I have just installed software to get an insight of a potential viewshed of a marine based windfarms around a Island. I am using an ASCI file as the map for the Island, however I am not getting any viewshed whenever I place any structure a few meters away from the coast. However, this is working fine when I place a structure in a bay. I tried placing structures on a sister Island but the effect was almost invisible on the other land since the view spread across the water. Is there a way how one could go around this issue? Any help would be appreciated.
Comments
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It sounds like you are placing your transmitter at a location where there is no elevation data, so a view shed isn't generated. I think what you need to do is replace all invalid values in your terrain layer with 0 so there will be valid elevation data there. To do this, simply open the Control Center, select the terrain layer(s), press Options, then go to the Adjust Elevations tab and select the option to replace invalid values with 0.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com -
Yes It worked out perfectly well.
Thanks
jdouglobal_mapper wrote: »It sounds like you are placing your transmitter at a location where there is no elevation data, so a view shed isn't generated. I think what you need to do is replace all invalid values in your terrain layer with 0 so there will be valid elevation data there. To do this, simply open the Control Center, select the terrain layer(s), press Options, then go to the Adjust Elevations tab and select the option to replace invalid values with 0.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com -
Hi I have another viewshed problem. I am trying to export a viewshed generated on GM as a KMZ file. I am right clicking on the viewshed generated as a layer and go to layer and Export layer to new file and save as KMZ. The problem is that the image on Google Earth is different from that generated on GM. I've been checking different boxes but keep getting teh same image over and over again. I need the same image. Tried saving as jpg but got the correct image on a white background, which I don't need.
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Hello,
How are the images different? Can you post a couple of screen captures to illustrate?
Cheers,
Bob -
attached file with printscreens
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Hi,
Can anyone explain why I am getting different images please? I attached printscreen in previous communciation but so far there was no reply. -
Hi,
The area is to complex to draw in GE.
Try this settings
Or simplify the shapes prior to export.
If you load back the kmz file to global mapper I suppose it s OK.
In the end, if nothing works, do the viewshed directly in Google Earth.
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Thanks for your reply, however note that the viewshed obtained through GE are no match with those produced by GM and I need an accurate viewshed not an approximate one. Secondly, I've done this process several times before and exported into GE as KMZ files but never got such a result. However, I will try your suggestion.
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jdou said:Can anyone explain why I am getting different images please? I attached printscreen in previous communciation but so far there was no reply.
If you are not getting a timely response on the forum, you should always feel free to contact Blue Marble Support directly via email (geohelp@bluemarblegeo.com). Please provide a detailed description of your workflow, and sample data that can be used to reproduce your results. Thanks.
Cheers,
Bob -
Tried exporting it using the above settings but always got the same results. Any other solutions would be most welcome.
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