Choosing a video storage solution for a surveillance environment can be a difficult task in reality. If we happen to zero upon a solution, the next question will be how long the captured surveillance videos have to be stored. Is it for 1 week, 1 month or 1 year? This has become a fundamental question to every surveillance system manager. As the duration period of video storage becomes critical, when a situation to produce video evidence arises. If the surveillance video is stored for too short time, then it can make you helpless in situations when a piece of recorded evidence is required. If it is done for too long time it could waste the fair amount of IT resources and budget in most cases.
So, here is an analysis which will help in examining how long a surveillance video has to be stored in a surveillance environment.
Storage fundamentals followed while designing a surveillance system depend on the frame rate and resolution of the recording cameras: how much storage will be needed (approximately)? What is the storage type which has to be selected (NAS/SAN)? Which features should be covered by the storage appliance, say redundancy, RAID usage, some other? Last, but not the least will be to determine whether the recording of videos will be in continuous mode or on motion based. It is a wise decision to go for intelligent way of motion based recording as it will save a lot of storage space from being wasted and thus will help in saving IT resources.
The key drivers which influence the storage duration factor are cost of maintaining the storage and how long does it take for the users to know that the need for video evidence from the surveillance system is needed as well as how long does it take to retrieve the video.
Incidentally, demand for video evidence is usually within a period of few days or weeks and some extra time is needed to retrieve the video from the sources.
To be honest on the above aspect, there are no international or national standards to be followed while designing surveillance storage. All depends on the needs of the surveillance environments and budget allotted for that particular IT activity. But generally, 30 days to 90 days period of surveillance recording is generally followed in this regard. This includes European continent as well, where a standard of 30 days minimum/maximum is followed. But this can be altered as per the requirements of the surveillance needs of an organization/enterprise.
To be specific, they are only four themes which emerged as applications requiring long term storage duration.
Government organizations related surveillance storage must be maintained for 90 days and that has become a mandatory in all parts of the world. But, certain FDA compliance laws suggest having a 180 day (6 months) surveillance storage period. Due to the recent terrorist activities and increase in security concerns, it has become unofficially mandatory in United States, Australia and United Kingdom to maintain surveillance videos related public places for longer periods such as 6 months.
Till April 2013, due to privacy concerns the monitoring videos were only maintained for a period of 30 days and that too with many stipulated rules in place.
But in wake of events like the unfortunate incident in Boston on April 2013, many government/private organizations have started revising the minimum requirement of the video storage retention to longer periods of time.
Storing surveillance videos from interview and interrogation rooms for longer duration is seen in police departments. The videos are retained for a period of 999 days in general. In a military detention center, the videos are retained for up to 7 years.
All financial institutions including Banks & ATMs will need a 180 day surveillance video storage. For organizations that face significant litigation risk such as food or chemical firms will go for a 6 month -5 years period of video surveillance storage.
Going by the technological trend, megapixel driven surveillance can also show its influence on video storage needs. In order to get a higher clarity in images, megapixel IP cameras are deployed in surveillance activities. The higher the MP resolution will be, the more size the captured image will occupy on the video storage. For this reason, megapixel camera surveillance system demand significantly shorter time to keep surveillance videos. However, all depends on the needs of the application environment and the value the stored videos generate.
Impact of project size on storage duration can also be seen in environments, as integrators involving in larger projects insist on keeping videos for longer time than the small project specialists.
Hence the conclusion is that there isn’t any general hard and fast rule as to how long you should keep your video storage intact. It completely depends on the application needs and compliance requirements.
Note: The above said time periods were described from the experience of the integrators who had more than a decade long experience in the surveillance field. The duration might vary and there is no need to follow the specified periods as a mandatory.