Laser Remote Sensing

Introduction

Laser remote sensing (LRS) is the general term to describe the procedure to gain physical information on systems from a large distance with the aid of lasers. The technique is also referred to as LIDAR: light detection and ranging. The principle is simple: light from a laser strikes the system of interest and the returning light is detected by a telescope and analysed. The technology is developing from the 1970's but especially the rapid advances in laser technology and computers over the past ten years opened up a wide variety of applications. Most commonly LRS is used in atmospheric and environmental studies applied from an airplane, minivan or satellite, measuring concentrations of pollutants, mapping cloud formation and monitoring agricultural crops for stress. The latter example is being dealt with in the experiment chosen here. This is a special case of LRS since instead of investigating scatter properties one monitors the laser-induced fluorescence (LIF) of photosynthetic systems.

Photosynthesis is the process by which plants, algae, cyanobacteria and some other bacteria chemically fix the energy from solar light. This process involves a high number of different protein complexes and reaction steps, all tuned for maximal energy conversion (meaning minimal heat loss) and directionality. Photosynthesis is optimised for low-light conditions and several mechanisms exist to dispose of excess energy. Here, we will investigate the fluorescence pathway.

The LRS experiment that you can conduct is suitable for upper level high school students and undergraduate students as the experiment and the interpretation of the experimental data can be considered at different levels of complexity. The information provided through this website differs for high school and university/college students. So to proceed from here, first select the information appropriate for you.

Viewer

The remote lab can only be controlled from one computers. Others can monitor the experiment through a viewer program. The viewer program does allow others to download recorded data and can perform their own analysis using the data processing software that is available off-line.