The issue centres on the particular needs and challenges that port operations throw up, not least because they often combine extreme weather conditions with an industrial environment.
“There are some shortfalls with reliability when it comes using to magnetic or optical systems in ports, as they get ‘easily distracted’ by dirt, snow, humidity and even weed growth. On top of this, variations in light in the more extreme operations can also cause difficulties,” she says.
So, transponders appear to be the best option for port guidance systems. However, even then the industrial environment throws up specific difficulties, mostly because the machinery often emits interferences around the 60kHz mark that can disrupt the sensor’s signals. Ms Schael explains that there are ways round it, by changing the frequency band or compensation, depending on the system.