I have disabled night time MD as it is more easier trigger false positive MD, however, we have a snow today daytime, and I got a lot MD alerts. Does anyone has a good value for threshold/sensitivity so it can ignore tiny but multiple snow/rain drop, but works for one piece but big, solid objects?
any good practice prevent snow/rain trigger MD? (Dahua NVR)
- Thread starter akoei
- Start date
If your cameras have line crossing detection, that might help.
tigerwillow1
Known around here
I never found a way to "fix" this situation with motion detection. Rain and snow triggers with line crossing are rare. I've totally stopped using motion detection, too many false positives.
There is an expensive solution: buy a thermal camera and use it to trigger other cameras (if that is even possible with Dahua NVRs). I got one last Black Friday for just under $300 USD. While traditional cameras would trigger all night and all day in a snowstorm, the thermal camera would not. It isn't perfect, though. If there is not a lot of temperature difference in the scene, then the effect of sensor noise is highly visible in the video stream, and sometimes it causes the entire video frame to darken and brighten significantly sort of like a normal camera that is unable to settle on an exposure time. This can trigger some primitive motion detection algorithms. This happens very rarely, so I'd say 99%+ of my thermal motion detection alerts are legitimate. There was also one night when the sensor freaked out a bit and random patches of pixels turned pure white on and off, causing lots of false alerts, but that got resolved by rebooting the camera and the problem hasn't happened again.
One simple rule for me on MD. Only use it on cameras indoors. Use Tripwire outdoors.
nayr
IPCT Contributor
Disable IR and go w/External Illumination.