Measurement for Recovery - M4R
Measurement for Recovery - M4R

Where on earth am I?

NPL celebrates Space Week with latest Measurement at Home challenge

In celebration of Space Week, NPL has created a Measurement at Home challenge based on one of the most useful inventions of the 21st century, the Global Positioning System (GPS).

Signals from satellite, received by devices like smartphones, tell taxis where we are, help locate pets and are key in navigation.

The electromagnetics team at NPL use anechoic chambers to measure power of transmitters, response of receivers and blocking effects of materials. Their measurements include work on the type of radio waves used by GPS. The time waves take to travel from satellites to your device indicates distance, and therefore your location. Your device knows where all satellites are at any moment. Signal from one satellite indicates you’re somewhere on a circle. Another signal, from a second satellite narrows it down to 2 points. A with 3 satellite signals you can pinpoint your location on the Earth’s surface.  

Buildings can affect how well this system works as they can absorb the radio waves that bounce in between them. NPL’s ‘Where on earth am I’ experiment aims to investigate the true affects buildings can have on GPS accuracy.

Using a GPS Status app, we’re asking participants to record a range of results indoors and outdoors to determine how the GPS accuracy was impacted. Full details on how to participate and submit results can be found here.

In collaboration with the Institute of Physics’ Space Week activity, Andrew Hanson, Outreach Manager, Riley Ilieva, Higher Research Scientist and Peter Woolliams, Senior Research Scientist, will be hosting a live session on 10th October to discuss the conclusions from the data submitted by participants.

Andrew Hanson, NPL’s Outreach Manager states: “I hope that through participants’ evaluations of measurement repeatability (actually the range of locations recorded for fixed positions inside and outside of buildings) we shall discover how well we can trust GPS location in a variety of environments. From an educational point of view, the task is great in helping people understand the metrological meanings of the words accuracy, precision and resolution.”

05 Oct 2020