This is classic damage due to abuse.
Note the ‘trail’ that is formed as the pixels are damaged. As has been stated, a Laser operating in the passband of the cameras optics is well known for causing such harm to pixels. People experiment with Lasers and wish to check the beam quality. They have been known to destroy thermal imaging cameras by directly exposing the sensor array to the laser beams energy without adequate attenuation to protect it from damage.
FLIR have detailed such sources of damage and look at the SC660 image with its Sun induced burn-in damage. The FLIR SC660 uses an A-Si sensor array rather than VOx and FLIR say it is vulnerable to sun damage. Look at the ‘tail’ tracing the course of illumination and damage. Look familiar ? I know you say your camera is not damaged by the sun but there are other energy sources that are ‘in-band’ that can cause such damage. Even a simple high powered Halogen lamp is a broad spectrum radiator capable of harming a sensor array if enough energy falls within the passband of the cameras optics.
https://flir.custhelp.com/app/answers/detail/a_id/3192/~/exposing-camera-detectors-to-high-energy-sources/session/L2F2LzEvdGltZS8xNTg0MzYyNDU2L2dlbi8xNTg0MzYyNDU2L3NpZC9mVWhEbW9zSiU3RUUzVVM2VmI3WVpEUUd0REJZOUp5d3RnZnNiamUzR2cwQTlobjlLUzRRd3lRZHNlemRQTDdRTWdWYzVjVXJzNkRqTkFUZUolN0VtZWdzQzJheWFjbHkySjdoNHo4M2d1MTI2dlBnTjMyJTdFY1drRWFXYnclMjElMjE=So what is the damage caused you may ask ?
Well presenting an excessive level of energy to a pixel causes significant heating as one might expect. This excessive heating can cause a range of changes in the pixel. The possibilities are listed below:
1: Excess heat in the pixel and surrounding structures causes temporary defects in the image that decrease with time and are not permanent. Basically a ghost’ image that fades as the heat is dissipated from the sensors die.
2. Excess heat in the pixel causes permanent changes in the pixels thermal response but the pixel remains operational. This damage causes the pixel to appear hotter of colder than the rest of the pixels around it and is an abuse instigated non uniformity issue. Some cameras can correct fir this with the FFC function but more commonly, the camera will require a calibration that will create a new NUC and dead pixel table. The damages pixel(S) will be tested for response and either gain correction applied or marked as dead due to being outside the acceptable correction range.
3. Excess heat in the pixel actually burns its surface and renders it non functional due to warping of the pixel structure and potentially destruction of the supporting ‘legs’. The pixel is effectively dead. This dead pixel would need to be logged in the dead pixel table so that algorithms in the video processing stages can hide its presence, just like any dead pixel. Sadly life is rarely so simple as many pixels are often damaged and so dead pixel ‘clusters’ ASR’s formed. Such clusters would normally cause a sensor array to be rejected at the production stage. As such the dead pixel video processing is likely unable to cope with the cluster and either will fail to address it, or fail to hide it adequately. A full calibration is recommended in such cases anyway as there is a need to capture any and all effects if the damage on the sensor array. This ‘cluster’ type of damage is usually beyond rectification and requires a new sensor array to be fitted.
4. In extreme cases of excess energy, usually from a ‘in-band’ powerful laser, the energy melts the pixel causing collateral damage around it and can damage the die surface behind the pixel. Such damage is usually catastrophic and a large area of the sensor array ceases to operate. This damage cannot be addressed with new calibration tables and the sensor array is scrap. There can also be damage to the AR optical layers of the lens system if the laser is of a high enough power. This is extreme and foolish abuse of a thermal camera and may actually be an attack on the camera to deliberately kill it. Think military use
I hope this helps.
For information. The image you have provided shows user abuse and FLIR would reject any warranty claim made if it was one of their cameras sent for repair.
Fraser