Scientists at the National Geophysical Data Centre, Boulder, U.S., which is an affiliate of the National Oceanographic and Atmospheric Administration, have come up with a novel way to crowd-source geomagnetic data for their project to map the world’s magnetic field.
App developed They have developed an app called CrowdMag which is to be downloaded to your mobile phone. Enabling “background reporting” on this app will cause the phone to transmit vector magnetic data at regular intervals. Combining this data with that obtained from real-time solar wind data, the scientists will be able to create models of the Earth’s magnetic field.
“With satellite and airborne surveys you can achieve only a certain level of resolution. For example, our best geomagnetic model (High-Definition GeoModelling — HDGM) has a resolution of only about 28 kilometres. Citizen scientists, walking around the signal/noise sources, can achieve much greater spatial resolution,” says Manoj Nair, a scientist from NGDC, in an email.
Not only this, the contribution can also help the scientist to recognise and remove the effects of local sources of magnetic field, such as transformers etc, which cannot be identified in the satellite data.
But where is the need for a compass in the days of GPS and other geospatial technologies?
One reason One reason is that unlike a stationary device, the GPS does not provide a pointing direction. Also, satellite signals can get jammed, or they may stall. A map of the Earth’s magnetic field can act as a referencing system.
The privacy issues are also outlined clearly. The data are collected anonymously. Once the “send data” option is enabled in a phone, the phone transmits the following information: Time of measurement; location; location accuracy; magnetic data from the phone’s magnetic sensor; the phone’s model, which is needed because there could be many different types of sensor.
The statistics “From download statistics, we know that about 2,000 people are currently using it all over the world, including India. Currently, the highest number of users is from France. Denver metropolitan area has highest users for a city,” says Dr Nair.
“The app is freely available to all from Google playstore or from iTunes, and it contributes data automatically,” he adds. More information is available at the website: >http://www.ngdc.noaa.gov/geomag/crowdmag.shtml
