Abstract: A method and system are provided for marking marine channels. A single laser beam is selectively interrupted to produce an identifying on/off laser beam sequence distinguishable by the human eye. The laser beam is then expanded in terms of beam diameter during specifically timed periods of laser beam transmission. The expanded laser beam is projected along a beam path that is substantially along the center of a marine channel to be marked at a height above the water's surface. The height of the beam path is selected such that marine traffic may pass under the beam path without obstructing same.

Abstract: A solid monolithic spectrograph utilizes the Czerny-Turner geometric confration. It has a base constructed of BK7 optical glass to which all components are affixed with optical epoxy. The compact spectrograph operates in the visible spectrum in second order thereby permitting it to be smaller by a factor of two than if it operated in first order. The spectrograph is programmable and is capable of simultaneous multi-channel measurements of wavelengths and bandwidths of sources in the visible and near infrared spectral regions.