Hardware

SeaGIS supplies a variety of hardware relating to underwater 3D calibration and measurement.

There are several important design considerations for stereo measurement systems. The camera separation and convergence angle dictate the measurement precision and amount of stereo overlap (the effective measurement area), and should be selected to suit your application. In order to maintain 3D measurement accuracy the stereo camera calibration must remain stable. Movement of the camera within the housing must be minimised (eliminated), and the spatial relationship between the camera lens and the camera housing port must be maintained. Likewise the relative orientation of the left camera with respect to the right needs to be stable. Hardware must be designed and built around these considerations, otherwise poor measurement accuracy is guaranteed. See here for more information about calibration stability.

Discuss your stereo measurement requirements with us, to ensure you end up with a measurement system that stays in calibration and is fit for purpose.

Calibration hardware
A calibration hardware package consists of a calibration cube (used with the CAL software package to calibrate camera systems), a distance bar (used to independently check calibration results), and shipping case. The calibration cube collapses for transport. For typical applications the standard calibration cube is 1000x1000x500mm when assembled. For close-range applications a 500x500x300mm option is avaliable.

SeaGIS can supply custom-built calibration hardware packages.

Camera housings and camera systems
SeaGIS supplies custom-built camera housings designed specifically for use in stereo measurement applications. The housings incorporate multiple design features that help maintain stereo camera calibration, particularly when housings are opened and closed.

Baited remote systems
SeaGIS supplies galvanised or stainless steel stereo camera systems suitable for remote baited stereo video deployments. Systems include the frame, a base bar, bait arm, two camera housings, four removable ballast pieces (5kg each piece), and all required fasteners, clips and hose clamps. The camera base bar has a tilt adjustment and can be readily removed for storage, shipping and calibration (in stereo systems). Suits all SeaGIS camera housing types (typically supplied with long camera housings bodies that have space for a USB power bank).

Diver/swimmable systems
Camera housings can be integrated into light weight 'swimmable' stereo camera systems. The camera configuration is customised to suit your specific measurement application - small or large scale. This type of camera system can be used for transect surveys of fish or benthos, minimum approach distance (MAD), or for detailed measurement of individuals (for example, schooling behaviour).

Collapsible diver systems with transport cases are a popular configuration. They can be collapsed and packed in their case for transport whilst retaining calibration.

Aluminium base bar systems
Systems with a structural aluminium channel base bar to suit long camera housings bodies with space for a USB power bank. Suited to applications where the camera system will be attached to already existing infrastucture (ROVs, traps, nets, wind farm infrastructure, moorings, etc.). Can be one-piece or collapsible, can be supplied with handles as a diver system.

Stainless base bar systems
A 316-grade stainless steel base bar and bait arm with two camera housings (typically long camera housings bodies with space for a USB power bank), hose clamps, clip, and fasteners. Typically used as the photogrammetric base for building baited remote stereo camera systems. The base bar suits all SeaGIS housing types (including short housing bodies and long housings bodies with space for a USB power bank). A length of 20mm PVC tube (not supplied) will slide inside the bait arm to complete the bait arrangement.

Pelagic systems
A structural aluminium channel base bar with two camera housings (typically long camera housings bodies with space for a USB power bank), hose clamps, bait arm and clips, fasteners, inverted 'Y' yolk and plastic end plates. The bait arm can extend behind the base bar to add a counterbalance for the bait and the base bar has a tilt adjustment with respect to the yolk. Plastic end plates bolt on to the ends of the base bar in place of the yolk, and create a base bar with overall dimensions and mounting hole pattern identical to the stainless base bar system. Suits all SeaGIS housing types (including short housing bodies and long housings bodies with space for a USB power bank). A length of 20mm PVC tube (not supplied) will slide inside the bait arm to complete the bait arrangement.