4.4
436 reviews
50K+
Downloads
Content rating
Everyone
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About this app

Introducing CrowdMag's newest feature: Flight Mode, which lets you contribute to scientific research by measuring the magnetic field as you fly around the world. To get started, simply provide your itinerary on the CrowdMag app, and you'll be able to turn your flight into a scientific expedition. Check out this step-by-step tutorial for measuring data while flying: https://www.noaa.gov/education/resource-collections/data/tiny-tutorials/crowdmag-flight-mode.

CrowdMag is an app that lets you measure the local magnetic field using your smartphone. You can view the data as a graph or a map in nanotesla units. CrowdMag measures the Z (downward component), H (horizontal intensity), and F (total intensity) magnetic field components. You can use CrowdMag for measuring magnetic data during outdoor activities, while flying, or to conduct your own experiments. You can also share it with NOAA to help scientists better understand Earth's magnetic field.

If you're going for a walk, run, or other outdoor activities, you can use CrowdMag to measure the magnetic data along your path and save it as a "magtivity." And, if you get a new phone, don't worry! You can export a backup of your CrowdMag data and save it on your computer. This way, if you have to reset your phone or switch to a new one, you can import your backup and continue using CrowdMag without losing your data or progress.

CrowdMag also has a magnetic calculator that provides magvar (declination), the magnetic field's dip angle, total magnetic field, and other magnetic field components based on the latest World Magnetic Model (WMM2020). Some of the other features of CrowdMag include creating your own magtivities, customizing recording frequency and location accuracy, exporting your data via email or Google Drive, and seeing generalized crowdsourced magnetic data from other users.

And, before we forget, CrowdMag also features a compass that distinctly shows both true and magnetic north. As an added feature, the compass also has a 3D display with an optional audio output - check it out!

CrowdMag features:

* Create your own magnetic activity (called a "magtivity")
* Measure data while flying
* Customize recording frequency and location accuracy to your preferences
* View your magnetic data on an interactive Google Map
* Graph your data as a time series line chart
* Check the quality of your data by comparing it with the World Magnetic Model (WMM)
* Export your data as a CSV file
* Clear stored data on your phone when you want to start fresh
* Choose to share your data with NOAA (optional)
* See generalized crowdsourced magnetic data from other users
* Use the live magnetic compass for 2D and 3D rendering
* View information about the current solar magnetic disturbance
* Use the most up-to-date magnetic field model (WMM2020)
* Export your data via email, Google Drive, or other options
* Export a CrowdMag backup to save your contributions' status and data
* Import your CrowdMag backup (works across different phone platforms)


Visit https://www.ncei.noaa.gov/products/crowdmag-magnetic-data to see crowdsourced magnetic data.
Updated on
Jan 18, 2024

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
Learn more about how developers declare sharing
This app may collect these data types
Location
Data is encrypted in transit
Data can’t be deleted

Ratings and reviews

4.4
412 reviews
Jacob Bingham (UFTS)
February 14, 2024
I wish this wasn't buried in the search results among thousands of garbage compass apps, this app (which is literally from NOAA themselves) is a compass, allows you to calculate magnetic declination and true north, calculate changes in the magnetic field using a model, crowd source (log and contribute) to a magnetic field model, and more. It uses old Android UI elements, but still receives updates (most recent one added a 1 Hz log rate option) so I will not complain.
2 people found this review helpful
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NOAA's National Geophysical Data Center
February 20, 2024
Thank you so much for your feedback.
Amanda Sousa
February 4, 2021
We love the app! I fell sensitive about the electromagnetic waves and radiation and we are specially today experiencing a high level variation from our pattern. We live in the middle of south America and we saw an incredible increase of our numbers. From 23.000nt to 149.000 and it's not going back normal! From 02 Jan 2021. Even our phones started to break with no apparent Reason....
25 people found this review helpful
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Rand Flory
March 12, 2022
I use the app to determine magnetic declination at my location. It works well, but I have a suggestion as to the readout of the declination. BY CONVENTION, positive declination is east and negative declination is West. As I sit here, that is easy to remember. In the field, it may not be. To reduce confusion when setting the declination on a compass, which marked East and West, but NOT +/-, how about reporting the declination like this: 10.43 (E), or -10.43 (W) Adding this would be a big help.
17 people found this review helpful
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What's new

* Added 1 second polling rate (on newer androids it might be slower, as in every 5 seconds)
* Recording now asks for permission from the user to use an alarm