Question 1

What is GEOCAL's accuracy?

Accepted Answer

We have achieved at least the accuracy level of conventional test-chart-based measurements. GEOCAL also provides the outer (angular) orientation, which can't be measured with traditional methods.

Question 2

What is the device-to-device variation?

Accepted Answer

We currently do not see a risk for significant device-to-device variation. Quantization is still ongoing.

Question 3

In the case of calibrating stereo pairs, how long can the stereo base be?

Accepted Answer

This case depends on the diameter of the DOE (Diffractive Optical Element) and the diameter of the camera's entrance pupil. We currently expect a stereo base of 60 mm for cameras with small lenses for the first GEOCAL device and much larger ones for future devices with larger beam diameters.

Question 4

Can the wavelength of the laser be modified?

Accepted Answer

It may be possible to select a laser with a different wavelength, but the laser and the DOE work as a system, and therefore a change in one component needs to be verified in the other. Thus, we start with 633 nm, an excellent choice to bridge visible and IR wavelengths to each other and 935nm specifically for NIR applications.

Question 5

What is the limit of the distortion model?

Accepted Answer

We use rotationally symmetric distortion models, primarily those based on OpenCV. In some cases, e.g., for cameras behind a windshield, this model may not work accurately. Therefore, we are investigating alternative models that may be better suited to certain applications.

Question 6

What is the uniformity of the illumination?

Accepted Answer

We are working with a DOE and a standard frequency-stabilized laser. This combination creates some variation in uniformity. However, we keep the uniformity high enough to achieve good geometric measurement results within most cameras' dynamic range.

Question 7

Can GEOCAL be used in a production environment?

Accepted Answer

Yes. With our experience building hardware for production, we see GEOCAL being useful in development labs and on the production floor, performing geometric calibrations and alignment for a wide variety of cameras.

Question 8

Can the number of dots in the camera sensor be adjusted?

Accepted Answer

The number of visible dots in the image depends on the field of view. The standard DOE design is intended for a field of view between 30° and 120°. Please contact us if your application is outside of this range. We also offer a DOE with a grating constant of 15µm, which may be an option if your camera is wide-angle and low-resolution.

Product Specifications

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