In February 2017 CSER jetted off to Austria for the third year in a row. We have been providing measuring services for The Jump! A Channel 4 reality show in which celebrities and sports stars compete in a series of Winter sports events.
In 2015 we helped TwoFour (the production behind the show) to measure the height of jumpers launching themselves from a formidable snow ‘kicker’ (read about this trip on our blog).
In 2016 we returned with an expanded remit. In addition to ‘air jumps’ we would also measure the distance competitors achieved in a traditional ‘ski jump’ event. This required us to adopt different measurement techniques.
To measure a jump we used two high speed cameras which we attached to lighting towers and positioned them to observe the landing area. By using two cameras we ensured that we had a fail-safe system and it also increased the reliability of our measurements. The system isn’t automatic and relies on expert user judgement – both users were within a few cm of each other most of the time.
Measuring a ski-jump introduces complexity, the measurement area isn’t perpendicular to the camera. In order to be able to accurately gauge jump length, a complex calibration process is required. To survey the jump’s landing we created a number of ‘control points’ which were at known distances from the take-off ramp. We located these control points in our camera images and used their positions to create a calibration which transformed the pixels from our camera images into the metres and centimetres which would be used to judge the competitors.
Each jump was measured at the instant that the competitor made full contact with the slope (both skis) and the measurement was taken from the back of the rearmost boot. The pixel co-ordinates were processed using a bespoke software program and the length of the jump was relayed to the production team. All of this had to happen in around 20 seconds. Luckily the team has been working on this for a number of years and they have progressively become more efficient by refining the process.
The 2017 show was a great success which saw a new record for jump length of just under 19 metres. After getting a behind-the-scenes look at the show for a number of years, it’s very apparent the dedication and bravery of the contestants. The jump itself is formidable and getting down it is a massive achievement. To actively compete and push yourself to the edge has always greatly impressed us.
To give you an idea of how close all the finalists were, we’ve created a composite image that shows the images we used to take jump measurements. Spencer Matthews is in first place with Louis Smith closely behind. In third place is Jason Robinson with Amy Williams closely behind in fourth. Using the calibration we created on the night I’ve mapped some lines which show metre marks across the landing slope. As you can see, because the slope is on an angle in the image, the lines are closer together at the top of the slope (which is further away) than at the bottom.
We hope to be able to measure the jumps for a fourth year in 2018!
Simon Choppin and Marcus Dunn