New Classical Optics | Components • Devices • Systems

GLOBAL LIGHTING STANDARD (2015 – 2020)

Mobile street light characterization system

Contact: Henrik C. Pedersen, Henning E. Larsen, Paul Michael Petersen, Linda Christel

This project started – like many others – at the coffee machine. Former colleague, Jakob Andersen, was going to do quite a few manual measurements on several stretches of street light. Henrik C. Pedersen came up with the idea of placing a measurement system at the roof of a car and then acquire light data while driving under the lamps. Three years after spin-off company Global Lighting Standard was borne.

PROBLEM

In 2015 DTU Fotonik founded the Danish Outdoor Lighting Lab (DOLL), in which new street lamps could be tested. However, at that time street lights were tested manually using a hand held luxmeter that had to be moved around to 50 locations between each pair of lamps. This was very time consuming and very often measurements were disturbed by traffic.

SOLUTION

The solution comprises a metal bar placed on top of a car, in which the bar is equipped with an array of light sensors, two up-pointing cameras placed at each end of the bar, and an accurate GPS unit placed in the car. While driving under a street lamp, it’s position with respect to the car is calculated using the two cameras (triangulation). The light sensors’ measurements can then be converted to “ground level” light values.

Measurement bar placed at the roof top of a car. The light sensors collect light data that are later converted to ground level.

The developed light measurement unit mounted at the roof of our car.

Heat map of a light distribution on a road stretch equipped with 14 street lamps.

Global Lighting Standard - Mobile Street Light Characterization System

RESULTS