The European Space Agency (ESA) is developing 3-D imaging lidar as a navigation aid for deep-space exploration. Lidar operates in the same fashion as radar but with shorter wavelengths since it uses light rather than radio waves. A pulsed laser beam scans targets by measuring the time it takes for the light to bounce back; its shorter wavelength offers more precise measurements — nanometers rather than the centimeters offered by radar. Read More
