Multi-Channel DVR to record signal with interference

[nab 0]

Hi,

 

I'm building systems to record drone FPV footage. For that, we transmit image from an onboard analog camera through radio, and output the signal to a screen or to some goggles the pilot uses for flying. I'd like to record multiple streams to compare different systems and also record views from multiple pilots during races.

 

When flying in closed environment like inside buildings (that are often metallic) or in forest, we often get bad signal, like dropouts, glitches and snow, comming from interference, multipathing of radio transmission or just bad signal power at reception. A lot of recording systems blank out the video signal in these cases, so that the recording and display stops. I'd like to still be able to see the image, which is actually still pretty usable and also need to see it to compare how good different systems are.

 

Does anyone have experience with multi-channel systems and can tell me if those security systems still record image with bad quality signal ? Systems like the HikVision analog/hybrid (HDTVI?) recorders or the Dahua HDCVI recorders?

 

For more details, the video I receive has these types of issues:

 

* Multipathing: reflexions of the signal on obstacles, those are the white horizontal bands:

 

* snow: when the signal fades away:

 

 

With those glitches, a lot of the recording and viewing systems blank out or show a blue or grey screen, like the system on the right:

 

 

The image comes from cameras like these:

http://fatshark.com/product/1745.html

http://www.surveilzone.com/26*26mm-Plastic-Case-13-CMOS-700TVL-Mini-CMOS-Camera-Super-WDR-g-1414

 

And are transmitted through A/V radio transmitters:

http://www.immersionrc.com/fpv-products/25mw-5-8ghz-av-tx/

http://www.immersionrc.com/fpv-products/duo5800-5-8ghz-av-rx/

[brebenac 0]

Any analog system from Dahua does record the image "as is". Even the "no video" type of signal, when the sync is lost is recorded as a black image with the OSD (channel name and time) on it.

The HDCVI system cannot be used to receive analog signals. HDCVI cameras cannot be used to send image through A/V wireless systems, so the options here are pretty limited. Use a standard analog system if the cameras are on pure analog format.

And there's the "tribrid" option where you can record analog/HDCVI/IP signals on same unit...