Do you own any GPS devices or equipment that relies on GPS to function? If so, now is probably a good time to check whether or not those products are protected against the GPS Week Number Rollover issue — a sort of mini Y2K Bug for GPS receivers that will occur in April.
The bug isn’t disastrous and should only hit a small number of GPS devices, but for those impacted the results could be severe, resetting the receiver’s time and corrupting its location data. Only older devices are at risk, though, and if you’re just using a commercial device the fix is simple: just check that its software is up to date.
The rollover issue itself is caused by the fact that GPS systems count weeks using a ten-bit parameter. This means they start counting at week zero and reset when they hit week 1,024. The first count (or “GPS epoch”) started on January 6th, 1980, and the first reset took place on August 21st, 1999. That means the next one is due this coming April 6th.
When the rollover happens older devices may reset their date, potentially corrupting navigation data and throwing off location estimates. GPS relies on precise timing data to operate, and each nanosecond the clock is out translates into a foot of location error.