How do I obtain measurements of exterior corporate signage at the top of skyscrapers...from the ground?

July 6, 2009 10:59 AM

How do I obtain measurements of exterior corporate signage at the top of skyscrapers...from the ground?

I'm a graphic artist who has been asked to obtain/determine the exact dimensions (height + width + depth) of two dozen+ specific skyscraper's worth of corporate signage (usually mounted towards the top of the building). These buildings/signs look similar to those I'm researching:

Example 1

Example 2

Example 3

My first inclination was to determine each building's height and number of stories, then use this information to guesstimate the respective sign's dimensions. I also thought about doing a pixel grid overlay and setting up a pixel to feet ratio. Unfortunately I was told that guesstimates aren't acceptable.

I really want to avoid contacting two dozen companies and/or building maintenance departments and inquiring about their signage--it seems unlikely that they would have the information I'm seeking, plus in this day and age such a request would probably be considered suspicious at best.

Short of hiring a survey company with fancy scopes and lasers (not an option) how on earth can I measure these signs from the ground? Or, alternatively, how can I creatively obtain the dimensions without measuring or rapelling?

posted by muirne81 to media & arts (5 comments total)

Your city may have specific permits that these buildings had to grant for these signs to be erected - perhaps the building inspection or planning department of the city would have records of permit requests - which would probably list dimensions.

Alternately you might try to determine which sign company did the jobs in question and ask them for details- they may be willing to show off prominent examples of their work, including dimensions.
posted by gyusan at 11:10 AM on July 6

For width, I would try to run a long tape measure at street level to get a measurement of the landmark architectural details that line up wit the sign.

For height, I'd hold two rulers (at right angles) at about the same viewing angle as the photos and make semi accurate guess.

Then I'd infer a bullshit degree of accuracy by defining the distance down to the inch or cm.

Then I'd say I used a computer.
posted by bonobothegreat at 11:27 AM on July 6

You can use a clinometer to measure the how far away from the ground the top and the bottom of the sign are. Then subtract these two values to find the height of the sign?

Width and depth might be harder, but once you have one dimension (height) you could try work out the others by using aspect ratios measured off photos. I think you'll need to take photos from appropriate angles (face on, and sideways on). If the signs are of a standard corporate logo you could cross-check the ratio on a web version of the logo, perhaps?
posted by Tapioca at 11:30 AM on July 6

Seconding a permit search; that's the first place I would look, especially if the zoning regulations are restrictive.

Having bought and sold transits in the past, I know you can get a really good transit off eBay for about $50-100 as long as you skip the new/fancy/antique models, and avoid bubble levels (which won't work for this purpose). I ran some tests with an 1960s Craftsman transit I had that I had bought for $45, and I determined I was getting about 1 inch of accuracy at 800 ft. Therefore with a baseline distance to the building and use of the trigonometric tangent it's a piece of cake to get some very accurate estimates.

The only thing you'd have to be concerned with is building security getting creeped out, so if you get out tools like that, it might help to don a work helmet and reflective vest so you blend into the background. I know an engineer who wears a helmet on residential/commercial building inspections for that purpose, so it's no big deal. Also if you rent or buy a good quality laser distance measurer you can get a distance to the building without having to approach it.
posted by crapmatic at 11:42 AM on July 6

In all of your examples, it looks very easy to measure the width from ground level.

Calculating the height after that is pretty basic geometry, right?
posted by rokusan at 12:52 PM on July 6