OPINION: GPS systems modelling could improve
By Pali Lehohla
JOHANNESBURG - When we were little boys herding cattle, we relied on a digital device that would let us know where the cattle are or where our home is.
This brown miniature scaly worm like creature the size of a bean with a sharp ended head, possessed magical digital capability. It acted like Siri - yours was to ask it ‘where is my home?’ -(a name it became known by incidentally) - it would swing its head and finally settle pointing in a particular direction, to a rapturous applause of herdboys.
Come to think of it, we actually conceived of prospects for a navigation device through this little creature. But that is where it ended and we never explored it further until we came to know about the compass at secondary school.
Many years passed and we could have hand-held navigation devices that you can tell to take you home. This is how the global positioning systems (GPS) has made life easy with a precision at sub-meter level.
I recall in 1990, after purchasing fifty Magellan GPS instruments for the Bophuthatswana Statistics Office, I would gladly set the instrument to my home and I would be excited when it said I had arrived.
However, the device was not very appropriate for drawing boundaries around squatter settlements because its accuracy was up to about 50 meters. Thus at any point in time you could be up to 50 meters off target. But now things have changed drastically. The remote sensing devices are able to measure the growth of the strands on a wheat straw.
Google gives you a street view and yours is to punch the address and the worm will swing its head and tell you where to turn until you get home. Like that deficient worm, the devices have as yet not built into themselves the three dimensions to include altitude.
This is where trouble starts.
Almost every week, at least more than four trucks get stuck in front of my house.
At least every year they will threaten to break into the wall of my home.
I have picked pictures and motion views of these trucks as they struggle up the steep incline, lose power and start reversing.
In 2019, a truck crashed into the wall and, fortunately, there was no one behind it otherwise, there would have been a sure and sudden death. I have written to the Tswhane Metro complaining about this.
In fact the municipality officials told me that trucks are not permitted to use that road. But they use it anyway and it is dangerous.
So yesterday again a truck snaked up this treacherous incline and got stuck halfway and started reversing. But the driver stopped it, hopped out, got a rock to serve as a stopper on the rearmost tyre.
So I asked him why he was using this treacherous route . He answered, like many before him, that the GPS showed him that route to follow.
Thus the GPS, without an elevation model, can direct you to your destination, but without telling you the obstacles ahead. All these point to systems that are not outcome and impact based. Without public participation, there cannot be a plan. Doing harm will always be lurking in the rear to attack.
Dr Pali Lehohla is the former Statistician-General of South Africa and former head of Statistics South Africa. Meet him at www.ie.org.za and @palilj01