02-19-2011, 07:25 PM
Interestingly if you take Wolfgang's photo as an example we have present a variable yardstick and that is the rail gauge as it diminishes into the background.
So lets say for argument you wanted to know the size of those two garage doors on the white house to the left of the tracks in the centre of the photo?
How do you measure them? Well we know that the gauge is most probably standard gauge at 4' 8 1/2" or 1435mm, so then if you measure the track width when level with the garage doors you will have a known dimension to work from. We also know from personal experience that the doors in all probability must be able to have a car drive through so that will act as a checking measurement.
The all time classic example of this yardstick method occurred during WW2 when an RAF Spitfire on photo recon took a photo of a Wurzburg radar installation. Standing at the bottom of the radar unit was a German soldier looking up at the Spitfire as it zoomed past. Photo interpreters back in England were able to use the height of an average male [at that time] to then work out the approximate diameter of the radar dish to work out its operating frequency and so know where to begin searching the radio wave spectrum and begin developing countermeasures. A photo is truely worth a thousand words.
Mark
So lets say for argument you wanted to know the size of those two garage doors on the white house to the left of the tracks in the centre of the photo?
How do you measure them? Well we know that the gauge is most probably standard gauge at 4' 8 1/2" or 1435mm, so then if you measure the track width when level with the garage doors you will have a known dimension to work from. We also know from personal experience that the doors in all probability must be able to have a car drive through so that will act as a checking measurement.
The all time classic example of this yardstick method occurred during WW2 when an RAF Spitfire on photo recon took a photo of a Wurzburg radar installation. Standing at the bottom of the radar unit was a German soldier looking up at the Spitfire as it zoomed past. Photo interpreters back in England were able to use the height of an average male [at that time] to then work out the approximate diameter of the radar dish to work out its operating frequency and so know where to begin searching the radio wave spectrum and begin developing countermeasures. A photo is truely worth a thousand words.
Mark
Fake It till you Make It, then Fake It some More