Measurement of deflection

[Swidru]

Hi,
this is my first post so hello Everyone. I'm student of geodesy.

I was wondering if there is a way to surveying a deformation (deflection of a rail viaduct) in PhotoScan software?
I know that with a several cameras it probably is very easy, but I have only single camera. I have an idea, that I can take a several photos of a viaduct from a standing camera (not move the camera) while a train will be in move. In that way I will get few photos with a deflection of a viaduct. But is this possible to measure a value of that deformation and how to get this?
Maybe Somebody know other software which could calculate this?

Thank You in advance for any help.
Cheers,

P.S. Sorry for my English but I know it only a little but I'm still learning

[Swidru]

but can I compare a photos in cloudcompare? cause I can't generate a point cloud from a single photo, of course I will have few photos but the scenes in this photos will not be the same (deflection of viaduct) so I will receive bad data.

[gatsri]

its not posible with only one camera...
you need at least two, wich trigger at exactly the same time...

[chrisd]

Does a train (like a single engine maybe?) with approx the same mass, velocity and direction travel over the bridge at different times?

[Swidru]

Ristag,
I agree but only if I would like to get 3D points...
I'm going to set camera exactly perpendicularly to the bridge (I will do it by using a total station). In that case I can neglect deformation parallel to my camera, so I will recieve this deflection in 2D what is possible with a single photo

Chrisd,
That "different times" will be approx 30 sec. I'm going to capture all photos during the passage of one train.

[Swidru]

btw
I figured that I can use the difference of parallax, like in "old" photogrammetry when people have used stereocomparator to measure (I'm not sure how that machine is called in English) and I hope it will work.