Orca's Subsystems

These photos were taken 1 day before shipment of the hardware to Japan, and 116 days after receipt of the order.

The 80 cm telescope is the right, with the receiver mounted on its left side. The telescope is a fast Newtonian design, which we have found to be especially suitable for Lidar applications. It is efficient, insensitive to misalignment, and simple. The imaging quality is lower than a comparable Cassegrain-type design, but it is more than good enough to meet Lidar system requirements.

The scanner assembly is at the left. The scanner covers half of the telescope aperture. A special feature of the scanner is that it can be pulled away from the telescope when not being used (as shown), in order to provide full aperture capability for zenith observations. In addition, the scanner is on a hydraulically raised platform, so that it can be retracted inside the building when not in use. It is shown in the retracted position. When raised, it extends upward an additional 1m through a closely fitted hatch in the roof of the laboratory.

Detailed View of the Scanner

Elevation is scanned by the uppermost mirror, which is shown in its fully retracted storage position. Azimuth is scanned by rotating the entire upper frame assembly.

Interior of the 4-Channel
Receiver Package

Received light enters the receiver through a port at the top-center of this photo. The programmable field stop assembly, which is also located on a motorized focusing mount, is on the far side of the baseplate, and therefore not visible.