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11

We usually have data concerning where the ground is, so we have to use that. The ground determines a solid figure in 3D. You project this figure radially onto the unit sphere centered at the viewer: this maps the ground onto a region in the sphere. Compute the area of the remaining region: that's the solid angle subtended by the sky (in steradians). ...


8

This is a known issue: http://support.esri.com/es/knowledgebase/techarticles/detail/17336 Basically it's a problem with using a raster layer in the inset maps. If you can only use vectors on your insets the transparency works.


7

Your choice of DSM vs DTM will depend on whether there is best-practice guidance or regulations governing the planning process for which you are performing the calculation. For instance, Viewshed Analysis for planning in the UK, especially for windfarms, requires that you use DTM data (and specifically Ordnance Survey data). Analysis with DSM may be used ...


6

Here's an answer that comes from the computer graphics world rather than GIS -- hence, it's a description of an algorithm rather than instructions for which tool(s) to use. Definition: a ray is an origin + a direction; it is the line that begins at the origin and continues to infinity along that direction. You need the following basic ingredients: ...


5

I cannot fully understand the code you have posted. When using the library OpenLayers, the usual programming pattern - as seen in the examples available at OpenLayers web page - consists on creating an instance of OpenLayers.Map that is stored in a global variable, so it is available to every function. Let us suppose that this variable is named map; then, ...


4

For a ZTV you would not normally use the Observer Points tool unless you need to know which turbine is visible at a given location and you have less than 16 turbines. Use the Viewshed tool. The simple setup you need for the calculation is like this: OFFSETA = turbine tip height (or hub height if requested by client) OFFSETB = 1.65 (in your case, I often ...


3

You can use an offset for one of the two routes. You find the option for each line style.


3

Ecotect (now an AutoDesk tool) enables you to do this. More generally, this is frequently examined in the area of daylighting and a tool from this field might be easier to use, than GIS. (Though I have heard of a GIS plugin that can do this and calculate solar exposure, but I've never managed to find it).


3

Sounds like you want to label your streets layer to show the street names. You can do this by right-clicking the layer > Layer Properties > Labels, then select the attribute field which contains the names: Hope this helps!


3

On/off doesn't appear to be an option with a data frame. Moving the frame off the document would work with elementPositionX and elementPositionY. Shrinking the frame to zero is an option as well. Initial code from python shell in ArcMap: >>> mxd = arcpy.mapping.MapDocument("CURRENT") >>> df = arcpy.mapping.ListDataFrames (mxd) [0] ...


2

You should use separate OpenLayers.Layer.Vector object for each WFS-layer. For example: var mylayer_1 = new OpenLayers.Layer.Vector("My Layer 1", { .... featureType: "mylayer_1", ... }); var mylayer_2 = new OpenLayers.Layer.Vector("My Layer 2", { .... featureType: "mylayer_2", ... });


2

You appear to be trying to turn off/on Layer Visibility in GeoWebCache which is integrated with GeoWebServer. Geowebcache is used for caching tiles to improve speed, not controlling layer visibility There are two ways to handle layer visibility Style the Layer using SLD in GEoserver, using<MinScaleDenominator></MinScaleDenominator> and ...


2

You might consider using the Visibility Index, which is a measure of the size of the viewshed for each pixel in a DEM. This way you could measure the overall visibility of a pathway or route. I wrote a blog on the calculation of the visibility index and some of the challenges involved that you might find useful here: ...


2

Have you considered using a model to automate this? You could use an iterator to step through each point and generate a view shed for it. Then if required merge the grids. If you do not know what I am talking about its time for you to open up desktop help and start reading up on model builder. This will allow you to automate this task.


2

I have a version 10.2.1 and tested exporting a dataframe (inset of Ontario) superimposed over a main dataframe and found that there are no issues any of the above-mentioned file types; PDF, EPS, JPG, TIFF (Example bellow) If I remember correctly some graphic-related transparency issues were addressed in the 10.2.1 version. If you do not have access to ...


2

You can do this with SQL. Without knowing how you're getting your data, I'd guess something like: SELECT ST_Intersects([the polygon geom], ST_LineFromWKB([point A geom], [point B geom])) AS Is_Obscured Obviously this is not a complete query. If it's not enough to point you in the right direction, then you'll need to share some more details.


2

I did exactly what you say and everything is working ok; some tips: Check your layer properties: in "General" select the radio button "'don't show layer when zoomed:', and after that define the scale in the textbox: 'In beyond'; click 'OK' Check if it is working: in the standard toolbar you can put any scale you wanted and check if your last setting is ...


2

The best way is to use viewshed (observer point does not seem necessary based on you question, except if you want to know which spire can see which WTG). First you determine the locations where you could see your WTG (viewshed of the spires), then you use "extract multivalue to point" to transfer this information from the resulting raster to each WTG point. ...


2

You could use the iface.mapCanvas().layers() method, which gives you only the checked layers in the ToC, i.e., no need to iterate through all map layers. You should then iterate through checked layers to evaluate if their scale-based visibility contains the current map scale, like this: canvas = iface.mapCanvas() for layer in canvas.layers(): if ...


2

The Viewshed tool uses a single DEM as input. @MappaGnosis explains clearly that you must decide whether a DSM, DTM or a combination of the two is best for your input DEM. By default, the observers eyes are at DEM + 1 (default OFFSET A = 1). So, yes, if you use the DSM as your input DEM and specify nothing else the observers eyes will be one meter above the ...


1

Here is a list of all of the Keyboard Shortcuts and Tips that is provided with ArcGIS for Desktop. It looks like pressing spacebar while you have the layer selected will turn it off, and then pressing it again will turn it back on. This way you are free to roam the map and toggle the layer.


1

You can use zoom based styling in order to make layers (actually, the geometries inside them) appear or disappear depending on the zoom. This lesson about zoom based styling explains in detail the trick, but basically in each your independent layers you can do: #table{ marker-fill-opacity: 0.9; marker-line-color: #FFF; marker-line-width: 0; ...


1

If you have access to 3D Analyst, there is a tool called Line of Sight from which you can directly create a Profile Graph that indicates which sections are visible and not from the observer points. See Creating a profile graph from line-of-sight results help file for details. Note the graphic output options are limited and may not allow you exactly ...


1

The scale you refer to as limited is not because of ArcGIS Online limitations. The basemap you are working with (those that are available as Basemaps in ArcGIS Online) has been cached in certain scale levels (the largest scale is ca 1:1128). That is why you cannot zoom in any further. However, you are not limited to ArcGIS Online basemaps. Feel free to add ...


1

You need to call setVisibility(true/false) on the layer. setVisibility All you are doing in your code is changing the value of static variables. This will not trigger any action on the layer. In your checkbox handler, you need to get a reference to the layer and change the visibility: triangleLayer1.setVisibility(value);


1

Ok this is how i solved it. I added a renderer to drawingOptions var sls = new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, esri.Color([255, 255, 0]), 3); drawingOptions.renderer = SimpleRenderer(sls); After i did that i had to enable dynamic workspaces in the service capabilities via the server manager. Hope this helps someone.


1

I don't know why "Feature to Raster" doesn't work, but found out that "Point to Raster" does! I just used my Shape-Layer as in-feature, the height as value field, MEAN for cell_assignment (That's the one for DEMs, right!?) and my wanted cellsize. Maybe this will help anyone in the future... :)


1

What I found out: It works, when I create a new base layer and set the parameter layer_gesamt.isBaseLayer = false.


1

I had to do something rather like this for my masters thesis, but with much fewer observer and target points. I'm not aware of a reasonable way to create a complete raster of "visible area," at least not one that wouldn't take a long time. Repeatedly running Viewshed, once for each centroid of the raster's cells, would certainly work... but as you've, ...


1

In ArcGIS you can use the Viewshed tool (Spatial Analyst Tools > Surface). The Viewshed lets you calculate the surface locations visible to a set of points or lines (see the documentation).



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