Combining your hobby with your work

Dr. Joan Girona had a data collection problem. The solution included model trains:

Dr. Joan Girona of the Institute of Agroalimentary Research and Technology in Catalonia, Spain, studies irrigation and the water and nutrient needs of fruit trees. In a recent study, he wanted to measure the absorption of photosynthetically active radiation (PAR) for use in analyzing growth and fruit production issues. Transpiration from fruit trees and overall evapotranspiration in orchards is closely related to absorption of solar radiation by the tree canopy, so this study would help researchers more accurately measure these processes.

The more measurements he could make, the truer Dr. Girona’s results would be, so he tried a few methods to accurately capture the needed data. First he set up a network of 32 sensors at various points on the ground around the fruit trees to measure light as it came from many angles. Dr. Girona and his co-researchers found that the values were too distant from each other for good modeling of sun movement. To get enough measurements in a net of this sort, they would need more than 1200 sensors, along with the associated dataloggers and multiplexers—impossible with the resources available.

As they thought about how to get measurements from so many points, they came up with a way to move the sensors around the measurement area precisely and quickly. They mounted the instruments [. . .] on small-scale model trains and ran the system on carefully laid-out tracks covering a large area around trees in an orchard. They placed metal markers every couple of inches along the track, and electromagnetic detectors on the train sensed these markers and signaled the datalogger to take a measurement at each point.

H/T to "Jeff the S", who thinks Dr. Girona should be nominated for a Nobel Prize for the "Best Use of Model Railroads in Agricultural Research".