Having just returned from the 10th Annual RIN Baška GNSS Conference in Croatia, the Brexit debate seems far away. A truly international crowd in a stunning location – Krk Island – pushed politics on to the back-burner for two days.
As usual we had several learned papers on ‘total electron count’ and ionospheric modelling.
Once upon a time the ionosphere was “sounded”, measurements being made by pinging signals up from the earth. Now scientists use sources ‘from the other side’ and measure the effect of the ionosphere on satellite signals. The ideal signals are those that come from the GNSS satellites themselves and here lies the irony. What to the navigator is an error adding to his or her uncertainty, to the scientist is a data-point adding more precision.
This of course would be an exercise in lifting oneself up by one’s own bootlaces were the scientists not blessed with two advantages over the navigator. Firstly, they know where they are and secondly, they work in collaboration with others to establish a global view.
It has always been thus. Navigators carry with them the knowledge of others in the form of charts and almanacs. Measurements made by people who know where they are to help those who do not. And when one looks more closely one sees evidence of this in GNSS itself. The user’s receiver can only operate thanks to ground stations tracking the location of satellites to maintain an almanac. In the past this “ground segment” was made up of learned court astronomers.
Modern communication has enabled these corrections to be real-time; the conference heard of the roll out of EGNOS Remote Integrity Monitoring Stations. And future receivers will contain better ionospheric models thanks to the research of the total electron count wizards.
So what of those who want to ‘take control’ and not rely on this community of helpers. Ded reckoning is one option but as the miles go by and the hours pass, errors just grow and grow. That smugness of knowing your exact location will slowly give way to a state of uncertainty technically known as being completely lost.
Navigation is deceptive. The loan yachtsman may appear to epitomise independence but is in fact totally reliant on thousands of years of international scientific collaboration.
Conference over. Now back to Brexit.