Polytechnic of Bari
Architectural Photogrammetry Laboratory
The photogrammetric archive

The objective set by the C.I.P.A. (Comité International de Photogrammétrie Architecturale) in its first meeting (Paris, 18 and 19 June 1970), was the establishment of an international archive of Photogrammetric Surveys of Architectural Heritage, duplicated and appropriately located in two secure centers.
The main difficulties that hindered the creation of this archive were essentially:

 
•   
   duplication of frames
  . At the time, terrestrial photogrammetry was derived from aerial photogrammetry, aimed at graphic restitution, giving primary importance to precision. Therefore the metric chambers used, as a support for the sensitive emulsion, rectified glass plates, of low sensitivity and, consequently, of high contrast. The duplication, besides involving a not negligible cost, was not exempt from a degradation of the image;   
•   
  the different format of the metric chambers
  . Each house, manufacturer of tools for photogrammetry, chose its own format and, consequently, each room required its own restitutor, which in addition to the particularly high costs, could only be used by specialized operators. The two central archives would have required prohibitive costs, both because of the non-depreciable equipment and because of the scarce use.    
•  
   the use of frames
  . When we talked about photogrammetric survey, we referred exclusively to the graphic restitution, which, made in specialized laboratories, ignored the needs of those who had to use the survey, so much so that these, also for economic reasons, preferred to resort to the metric tape. The stereometric pairs of frames, not only were not used for the very poor knowledge and diffusion of stereoscopes, but were doubled as they were considered "copies"

Today, thanks to digital cameras, photogrammetric surveying is within everyone's reach.
Once the concept of "normal case" has been clarified, anyone can calibrate their camera and use three simple 1st degree equations to program the return.
The StereoFot® 7.0 program, with its own archive, wants to be a concrete example.
If you think that:

   
•   the current digital cameras automatically provide a series of information, including the main distance and geographic coordinates;     
•  the internal orientation of the frame is fixed, in fact the film no longer exists, subject to deformation, displacement, etc .;     
•  frame duplication is a "no problem"     
•  the framing and the precision of the shooting, with a minimum of organization, can be verified on site, with the advantage, thanks to a simple key, of being able to archive the frames in real time (in fact the development and printing process has disappeared frames with the relative long technical times);

it can be safely said that the only problem to solve, in order to carry out the survey, is to take the two photos without changing the direction of the optical axis: in practice it is sufficient to slide the camera along an "L" bar and measure the moving anywhere in the room.
For the return it is sufficient:

    
• click on the "import photo" button;     
• enter the requested data (the indispensable ones are marked in red);     
• click on the "register" button     
• carry out the calibration, if the frames are loaded for the first time;

As for the results and, in particular, the accuracy of the survey, all that remains is to rely on the law of the Internet: unnecessary findings will not be consulted and will go down in the ranking!