Ships' distance becomes easy to see

Jan. 1, 2004
Because the U.S. Navy wants its ships to be capable of staying at sea for long periods of time, even when far from ports where they can be resupplied, the Navy has come up with underway replenishment techniques in which supply ships or helicopters stock combat ships with fuel, ammunition, provisions, and spare parts.

Because the U.S. Navy wants its ships to be capable of staying at sea for long periods of time, even when far from ports where they can be resupplied, the Navy has come up with underway replenishment techniques in which supply ships or helicopters stock combat ships with fuel, ammunition, provisions, and spare parts. In the case of ship-to-ship transfer, a cargo can be transferred via a trolley on a tensioned wire spanning the gap between ships. The conventional method of keeping track of distance between ships requires a line with evenly spaced knots strung between the vessels, along with intense monitoring by the captain and deck personnel. Maintaining the proper distance between ships during transfer becomes especially difficult in bad weather.

Click here to enlarge image

To ease this difficulty, engineers at Laser Atlanta (Atlanta, GA) have developed a laser-based proximity-measurement system that provides a distance readout on a large display, giving instant feedback on distance to the captain of the ship that is being maneuvered. The pulsed time-of-flight rangefinding system has a 904-nm-emitting laser diode as its source; the diode has an emitting area of 300 × 225 µm, which is imaged by 100-mm-focal-length optics onto the target vehicle, producing a square pattern roughly a foot on a side.

Click here to enlarge image

The laser is synchronized to a rotating mirror in the optics assembly so that the laser can fire at any combination of points along a scan line. An avalanche photodiode receives the return signal; both range and velocity are computed. Selective buffering of the return signal minimizes problems caused by stormy or foggy weather. Here, the ship in the center is the USNS Tippecanoe; the inset shows the display of the proximity-measurement system.

Sponsored Recommendations

Achromatic Lenses: High-Quality Custom Optics

March 13, 2025
Ensure clarity and accuracy in your optics systems with Lacroix’s achromatic lenses. Explore how our custom solutions minimize chromatic aberration for perfect results.

Manufacturing Considerations for Tolerancing Aspheres

March 13, 2025
Understand the critical factors in manufacturing aspheres and how Lacroix Optics ensures precise tolerancing in every optical component.

Explore Our Videos: Insights into Precision Optics

March 13, 2025
Get an inside look at Lacroix Optics with our collection of informative videos showcasing our capabilities, innovations, and processes.

Optical Assemblies: Reliable and Precise Solutions

March 13, 2025
Ensure your optical system works seamlessly with Lacroix Optics' custom optical assemblies. Discover the precision and reliability we bring to every project.

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!