Campus Light Illumination

[SamLipscomb]

Please forgive me if this is the wrong forum, but...

I am looking to calculate the illumination of lights on a campus. However, I have no idea where to start. I have not really had much practice dealing with the 3D/Spatial tools; I mostly dealt with the Network Analyst tools in the past.

I have found other instances of people doing something similar, but they don't really mention what tools they used or the steps they used to get there.  I am imagining the output to be a raster with cell values higher near the lights and lower away depending on the type, height, etc of the bulb.  I have found some equations that will help me calculate this, I just don't know where to begin in ArcMap.  So, does anyone have any advice or resources that I could use/follow to get started?  I'm looking forward to learning, I just need some help getting started.

Thanks,
Sam

[Anonymous User]

To get you started, I would create a point feature class representing campus lights (if you haven't already) and fill in some attributes such as light type.  You could then use the Euclidean Distance tool to represent the illumination from the lights (bright by the light then fading to dark).

For example, suppose you have 3 different light types.  Type A can illuminate up to 30 feet, Type B can illuminate up to 50 feet, Type C can illuminate up to 75 feet.  You could then select the points by each type and use the Euclidean distance tool using 30 feet for the max distance for type A, 50 feet for type B, and so on.  This will represent the light illumination if you use the white to black color ramp. 

In this case, the low values will be the brighter spots and the higher values will be darker as you're moving away from the lights.  This is a very basic scenario but this will get you pointed in the right direction.

Link to Euclidean Distance
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//009z0000001p000000.htm

Another option is to use buffers.

[EricRice]

Sam,

What is it exactly that you want to calculate? There are a number of good tools in the 3D toolbox that could get you going depending on your needs. Attached is a screenshot of the city lights in Philadelphia from our Virtual City Template. It�??s just point features symbolized with semi-transparent spheres based on the approximate illumination distance of each streetlight. You can intersect that sphere with stuff (eg: the ground in a public space) to calculate the area of effective light coverage, for example.


Best,
Eric

[SamLipscomb]

Awesome, thank you!  I think I can work with and build off of this, but this is certainly a start for me. 

One more question...At the moment, the raster created doesn't fully show the distance from the points on the edge; it's basically a box that just fits around the points I am testing.  Is there a way to set this to fully show the distances of those edge points without using fake points to make the box bigger?

[SamLipscomb]

Sam,

What is it exactly that you want to calculate? There are a number of good tools in the 3D toolbox that could get you going depending on your needs. Attached is a screenshot of the city lights in Philadelphia from our Virtual City Template. It�??s just point features symbolized with semi-transparent spheres based on the approximate illumination distance of each streetlight. You can intersect that sphere with stuff (eg: the ground in a public space) to calculate the area of effective light coverage, for example.


Best,
Eric

Hi Eric,

I'm trying to "quantify" the environment to help me study risk perception.  The idea is to build a three dimensional model of the campus to help calculate visibility, light intensity, etc... from given locations and use those variables in a multiple regression model.  I'll look into that template, I believe I used it once but must have missed the lighting part. 

Thanks for the advice,
Sam

[EricRice]

Set the Extent in the Environment Settings to something larger than the input point extent when you run the tool.

[EricRice]

I don't believe it's part of the template.  Just some guys upstairs playing around with our capabilities, nothing official.  That doesn't mean you can't do it though.

Eric

[SamLipscomb]

Ah, well I'll look into it regardless.  And thank you, I can't believe I missed that option, my bad.