Fig. 2. Coordinate system
Comparing the results of photogrammetric processing of images taken at different times (indifferent observation cycles), we determine the relative displacement of the markers.
This approach allows to monitor under different conditions (indoors, at the elevation of building, on bridges and at the industrial installations) and at different shooting distances (from 0.1m to 40m) between the camera and the object observed. Image processing in PhotoMicrometer is based on methods of photogrammetry, stereophotogrammetry, and also is based on high-precision measuring of marks. This allows monitoring with an accuracy of 0.1 mm to 0.005 mm, depending on the types of markers used. The deformations that the method allows you to measure with guaranteed accuracy can reach up to 5 cm on each coordinate axis.