The launch of a SpaceX heavy lift rocket in August of 2017 created some unexpected results in the earth's ionosphere, effectively punching a temporary hole in this portion of the earth's atmosphere. As noted in this article at ARS Technica, the ionospheric disruptions resulted from the rocket's unusual vertical trajectory, rather than a typical rocket trajectory that is more parallel to the earth's surface. Scientists say this disruption may have caused errors in GPS navigation of up to 1 meter. Why the errors?
With GNSS timing is everything. This diagram shows how satellite transmissions can be delayed by varying conditions in the ionosphere. Basically, GPS receivers determine their position based on the time it takes for satellite signals to reach them, and any interference with that time calculation impacts the accuracy of the result. If your GPS application is just to navigate the highways from city to city, the error resulting from this ionospheric disturbance won't make any difference, but if your application is precise surveying to centimeter accuracy, 1 meter makes a world of difference!
The concern is that as we become more dependent on GPS navigation for applications such as autonomous vehicles, and as the frequency of rocket launches increases, scientists need to better understand the influences of rocket launches on the ionosphere so that GPS calculations can compensate for these predicted changes in timing.
And on a more local note, we wish a Happy Easter to all!!