DIGITAL STORAGE IN SURVEILLANCE
All visual and audio data is now in digital format. It is very important to know what the storage retention is. Because if accident happened and you didn’t catch it at that time it can be gone. There are ususally two types of storage: Short-term Storage and Long-term Storage.
Short-term storage is the recycling of the available storage space using the first in first out (FIFO) principle. In other words, if recorders have a drive capacity to store for only 14 days, an incident that occurred three weeks previously cannot be retrieved – it would have been overwritten by the new recording during the last 14 days.
Long-term storage refers to indefinite storage of information. This typically happens by backing up the detected incident from the short-term storage to another media form and storing the information for a longer term by not allowing it to be overwritten or erased. Some users refer to this as archived storage.