High speed cameras are often synchonised, (aka genlocked, framelocked) together. All but the most basic cameras include the ability to input or output a sync signal for this purpose. Creating movies with frames captured at exactly the same instant has many uses, including:
Accurate motion analysis of an event with cameras at multiple viewing positions
- 3D imaging
If there are two cameras located close to each other, the simplest way to configure the cameras is connect the camera together with cabling. For larger number of cameras or large distances between cameras, this can get quite messy or very difficult to configure. In many outdoor testing environments, the length of cabling required often result in frame sync’ing being desired, but not actioned.
Instead of cabling, a GPS timing signal* can be used. If the camera includes GPS (like IDT’s NX-Air and Y-Series cameras), the internal clock of the camera is locked to the timing pulse of the GPS signal, so all cameras are totally in sync with each other. All that’s needed is a low cost GPS aerial connected to the GPS connector on the back of the camera, then choose GPS from the frame sync dropdown in the control software. There is no limit to the distance between cameras, so even if the cameras are miles apart, they can still be frame sync’d. Cable free sync’ing is also useful for indoor tests (eg where the cameras are on board a test vehicle and a trailing cable is not possible). GPS sync’ing can still be achieved indoors, with the addition of a GPS repeater, which receives a GPS signal externally, then transmits inside the building.
- How to configure cameras for GPS sync’ing
- What extra hardware is required?
- Which cameras can be wirelessly sync’d?
- Can everything be wireless (control, download, triggering…)?
*GPS satellites are more often associated with positioning (satnav etc), but a single GPS satellite only transmits a (very accurate) timing signal. Positional data is obtained by triangulating from 3 or 4 satellites.