A look at AHD and Analog Technologies
Also known as analog high definition close circuit television, AHD is surveillance that utilizes a coax analog CCTV camera cable, to be able to transmit 1080p and 720p video resolutions.
AHD can transmit video highest resolution analog CCTV camera in 1920 x 1080 uncompressed format. This technology can achieve reliable transmission of up to 500 meters of an HD video signal. It takes on advanced Y/C simulation filtering and signal separation technology. This effectively reduces color noise found in high-frequency regions.
The various types of analog cctv cameras comes in three formats:
- AHD08: This refers to image definition ranging from 960H to 720p and maxes up to 800TVL.
- AHD10: This refers to an AHD image definition equal to a 720p internet protocol (IP) camera.
- AHD20: This relates to the image definition of not more than 1080p.
Why Analog AHD Technologies are Preferred over HD IP Cameras
- In terms of picture quality, AHD offers superior live picture quality. This is because the pictures aren't compressed.
- You will get better video analytics results. This is because camera images are sent to the DVR in real-time and without being compressed. Compression generally degrades image quality.
- You will also not experience any lag as the live pictures are in real-time. On the other hand, IP CCTV cameras experience some lag because images are compressed in the camera. The compressed videos are also sent over LAN, and the pictures mustn't be compressed when being sent to NVR. This is a process that takes time hence possible lags.
- The technology is like that of analog CCTV camera. This is to mean, each camera has a connection to a DVR.
- It uses a 75 Ohm coaxial cable, but rather than transmitting video only; it's transmitting three signals simultaneously, i.e. serial data, audio, and video.
- The signals being transmitted cannot be affected by outside electromagnetic interference.
- There is a 500m maximum distance between the DVR and camera.
- You will need an analog CCTV camera to IP converter to convert from analog to IP CCTV cameras.
- There's no delay, latency, and compression, thus giving instant transmission of signals.
- Supports 1920 x 1080p and 1280 x 720p cctv camera quality full HD and HD video image quality.
- It is compatible with many different devices from varying manufacturers making the same technology.
- Low maintenance and ownership costs.
- AHD technology will give you Progressive-Scan high-definition analog video in full-frame.
- This technology utilizes the 960H wiring regulations, analog CCTV camera meaning users can easily upgrade from 960H to an HD CCTV by replacing the DVR and camera.
Can AHD Technology Replace Analog CCTVs?
While there was a time when the surveillance industry believed that analog CCTVs would have been faced out by now, that is far from the truth. In the year 2007, there was a rise in the popularity of megapixel-resolution internet protocol cameras.
However, their popularity was short-lived as more people realized that their price was high and set up more difficult. In came the HD-SDI in 2010, which has since been widely used to make HDTV and movies for years. Even so, there has also been a limited acceptance of good quality HD-SDI cameras. One of the reasons is their limitation as far as running a coaxial cable at a long-distance goes. HD-SDI also doesn't support video baluns.
AHD has since addressed the most prominent issue one of them being the Analog CCTV camera price. Other issues held back other HD surveillance cameras, preventing them from taking the lead in the analog Closed Circuit TV market. Installers now have the option of using coax cables like analog surveillance cameras. What's more, the coaxial cables will work at a similar max distance. Installers who prefer UTP cables like CAT5 have video baluns for their Analog AHD cameras.
In terms of analog CCTV camera price, AHD cameras have a slightly higher cost as compared to analog ones.
AHD Installation
AHD are suitable for these installation types:
- Small scale installations have a single DVR and about 16 x cameras.
- Those looking for an economical solution
- In situations where the installation will use current coaxial/fig 8 cables previously used in CCTV installation.
- Suitable for low-maintenance and low-budget CCTV installations.
Cables used by AHD cameras
AHD cameras use coaxial cables to connect to DVRs. These cables are similar to those used in conventional analog CCTVs. It is typically an RG6 or R59 coaxial cable. It is worth noting that an RG59 coaxial cable can run for a long distance without losing video.
Conclusion
Even though AHD has many benefits, it also has its weaknesses. For example, it has a limited ability to integrate with complex access intrusion or control systems. This is mainly due to a lack of support from major manufacturers.