I have taken a number of photos of a 400m long bridge with a UAV and have had problems getting it to calibrate. On inspection it seems that most of the keypoints for the images are coming from the surrounding vegetation with hardly any coming from the bridge itself (see images). The bridge is wrought iron with an iron deck with gravel infill (see close up). Is it that the photo was taken to far away…too close or is it just that this is not a suitable subject for photogrammetric modelling? .
There are many parameters to take into account to understand why there were issues during calibration. Was it possible to get a Point Cloud reconstruction of the bridge? or did the processing stop before? Next to the image with the orange crosses, there is a slider that shows how many images were used for each orange cross, what was the value of this slider in your screenshot? If it was high, it means that there could be other matches displayed, if it was low (e.g 2) then there were no matches found on the rails.
Maybe the repetitive pattern of the rails and bridge could make the calibration process more difficult.
More files that could help explain the calibration problem, would be:
Quality Report of the project (click Process > Generate Quality Report)
These cookies are necessary for the website to function and cannot be switched off in our systems.
They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences,
logging in, or filling in forms. These cookies do not store any personally identifiable information.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site.
They help us to know which pages are the most and least popular and see how visitors move around the site.
All information these cookies collect is aggregated and therefore anonymous.
If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
These cookies may be set through our site by our advertising partner (Google).
They may be used by Google to build a profile of your interests and show you relevant adverts on other sites.
They do not directly store personal information but are based on uniquely identifying your browser and internet device.
If you do not allow these cookies, you will experience less targeted advertising.