3D scanning is actually a rather difficult thing to achieve. 

I’ve tried many different systems and they all have limitations in one way or another. Some are not good for scanning small objects, while others cannot handle dark surfaces, and so on. 

3D Scanning Sunlight Issues

One of the biggest problems with many 3D scanning systems is outdoor use, where direct sunlight can wreak havoc with most 3D scanning systems. Consider the case of a structured light 3D scanner, which projects a cross-hatch pattern on a surface and then the images of the distortions are interpreted into a 3D model.  

In sunlight the structured light pattern is invisible because the scanner’s projector is not strong enough to overcome the brilliant sunlight. 

Thus I’m always looking for solutions that can make 3D scanning work better. Today I bumped into research that seems to solve one of the many 3D scanning issues: reflected light. 

Researchers from the Stevens Institute of Technology in New Jersey have been working on this issue as it relates to LIDAR scanning. LIDAR is a form of 3D scanning in which laser light is transmitted and reflected off target objects. Typically it’s used in outdoor settings where large landscapes or buildings must be 3D scanned. 

However, as an outdoor technology, it is also subject to the sunlight problem. Many objects in the field of view will also reflect sunlight towards the scanner’s sensors, and thus mess up the results. 

The researchers developed an implementation of single-photon noise reduction with something called “quantum parametric mode sorting”, or QPMS. 

Quantum Parametric Mode Sorting

How does quantum parametric mode sorting work?

It seems that the researchers were able to modify the outbound photons from the source laser to have certain quantum properties. These properties stay with the photons, even as they are reflected. 

Thus the sensor is able to filter out photons that do not have the assigned properties. This means that sunlight should no longer be an issue for LIDAR using QPMS. 

At top you can see a comparison of two 3D scans, one using regular LIDAR and the other using a QPMS system. The difference is quite clear. Also of interest is that this 3D scan was captured through a screen as seen on the left. If there was ever a barrier to 3D scanning, a screen would certainly destroy almost every 3D scanner’s chance of success. However, the QPMS technique worked very well in this situation. 

This development will certainly improve the capabilities of field-bound LIDAR devices, but my hope is that similar solutions can be developed for other forms of 3D scanning that also suffer from sunlight constraints. 

Via LaserFocusWorld