AVÃûʪ

Team Members: Huan Nguyen, Clint Olsen, Doan Bui, Ben Herman, Matt Zarekani, and Gabriel Yen

Guidance from: Dr. Richard Saltus and Dr. Manoj Nair from NOAA/CIRES

The measurement of Earth’s magnetic field has been an interesting and profitable field for scientists past and present. Such data allows for navigational techniques (through the creation of maps of the planet’s field data) and exploration of natural phenomena, such as the way Earth’s magnetic field shields flora and fauna from harmful cosmic events such as solar wind and radiation.

The scientists, both professional and hobbyist, who wish to record measurements of Earth’s magnetic field for interest and profit (e.g. in the creation of NOAA’s magnetic/true north declination models) currently face two main problems: the first is that noise is prevalent in magnetic measurements due to both internal and external interference. The data provided to NOAA is therefore not as accurate as desired. The second problem is that scientific-quality instruments are expensive, and difficult to deploy on a larger scale.

In the CrowdMag phone app, the current widespread tool for measurement of magnetic fields that both amateur and professional scientists can use, the internal noise comes from a variety of sources, the first being that magnetic sensors embedded in the phones are subject to interference from theÌýmetal of the enclosures, which holds the phone’s integrated circuits. These ICs also emit heat and electromagnetic interference, which has an outsized distorting effect on the magnetic sensors, invalidating measurements affected by thermal and magnetic interference.

This thermal and magnetic interference can also come from powerful external sources such as power lines, electrical transformers, large vehicles and other electromechanical structures. The scientific-quality instruments that are sophisticated enough to account for thermal and magnetic interference are difficult to deploy on a large scale due to cost, in both dollars and man-hours. In addition, operating and interpreting these instruments requires specialized knowledge.

The CrowdMag External Sensor (CES) implements a sensor system that abstracts the collection ofÌýimportant magnetic data from internal smartphone sensors to a portable external unit. This external unit provides a more accurate representation of data through the use of sensitive componentry which is communicated wirelessly to the CrowdMag mobile application.

The primary benefactors of CES are scientists and the citizen scientists looking to study the Earth’s magnetic field or satisfy their own curiosity. By crowdsourcing data collection, this product provides scientists with a cost-effective but accurate magnetic map. Ultimately, the CES has the potential to help on a global scale by improving magnetic modelling that ultimately contribute to navigational ability and understanding natural phenomenon associated with the Earth’s magnetic field.

The main feature of the CES is that it contains sensor technology about two orders of magnitude more precise than any available in a mass market device, allowing for accurate scientific readings of magnetic fields to take place in any location. This bridges the gap between scientific-grade data collection and practicality through portability, simplicity, and affordability.

Having a more precise, cheaper, and user-friendly sensor system is but half of the solution. Previously, there has been a concern over existing scientific equipment being durable enough to takeÌýmeasurements in more extreme climates and noisy environments. The CES addresses this issue by being operational at a wider range of temperatures and atmospheric conditions and is able to map and correct for internal and external sources of interference, such as heat, metal structures, and other artificial magnetic fields. In addition to its robustness and measurement accuracy, the sensor supports two functional modes: observatory and survey mode. Observatory mode addresses needs catered towards scientific applications where the long term collection of data is necessary at a single location. Survey mode is appropriate for many applications, but a common use for hobbyists is portable data collection over a potentially large area, allowing the user to generate a map of their magnetic environment.

In sum, the CES acts as a practical medium to provide data of high enough quality to be interesting to citizen scientists, as well as of practical use to professional scientists.