B4A Library Magnetics Library

Magnetics calculates the magnetic variation, inclination and grid variation (the last for lat > 55 deg or < -55 deg).

The WMMC.COF file is good for 5 years, the attached one is up to 2022. Hence you should put it in File.DirRootExternal & "/Magnetics", so the user will be able to replace it.

Edit: Version 1.1 enables the developer to select where to store the WMMC.COF file. The initialization method includes the directory as a parameter.
File.DirAssets cannot be supplied there. You must copy the file from there to another directory, for example:

File.Copy(File.DirAssets,"WMMC.COF",File.DirInternal,"WMMC.COF")
mg.initialize(File.DirInternal)

Edit: The file WMMC.COF has been updated, I attach the new file here (open the zip). It is valid until 2022 ! The library files do not change.
EDIT: A new WMMC.COF file is attached, valid until end of 2024. unzip and copy the WMMC.COF file.

Edit: Updated to ver 1.2
Edit: Uploaded ver 1.3, bug correction.

Edit : WMMC.COF file replaced with a new file for 2025-2030

 

[Erel]

A B4J project is attached.

Please test it. If there is any error then try to find it. It will be easier for you.

 

[derez]

The module works fine in b4a program.

 

[Erel]

In that case it should work in B4A, B4J and B4i.

 

[Andris]

In that case it should work in B4A, B4J and B4i.

See my follow-up post in iOS Questions here.

 

[derez]

Got this mail from NOAA:

Dear NOAA Geomag users,


This is a message from NOAA's National Centers for Environmental Information (formerly National Geophysical Data Center). You received this email because you opted for notifications related to NOAA Geomagnetic models or services. We would like to bring to your attention that, in the event of a U.S. Government shutdown, NOAA Geomagnetic calculators, Application Programming Interface (API) services and our web pages will likely go offline starting 2018-01-20. However, backup calculators and models will be available through the University of Colorado CIRES Geomagnetism site. URL https://geomag.colorado.edu/online-calculators#backup_calculators.


If you need assistance during the shutdown period, please send an email to CIRES Geomagnetism experts at ciresgeomag@colorado.edu or visit https://geomag.colorado.edu/about-us.html.

As the existing data file is valid until 2022 there is time to find how to replace it...

 

[Andris]

Got this mail from NOAA:


As the existing data file is valid until 2022 there is time to find how to replace it...

Derez, I think you should post this here: Announcements Thread. Thanks for the alert, and yes, we have time, but as is usual, it will be on our doorstep before we know it

 

[derez]

Got this mail from NOAA, regarding errors in the Arctic region.

 

[derez]

I got this message from NOAA, FYI, it seems that nothing should be done unless you plan to take your phone to the Arctic region...

Dear World Magnetic Model users,

This is a message from NOAA’s National Centers for Environmental Information

(formerly National Geophysical Data Center).

An out-of-cycle update for the WMM2015 model (WMM2015v2) is now available to you. Please note that we had provided the WMM2015v2 coefficients in a limited, pre-release in September, 2018. If you have already updated the model coefficient file (WMM.COF) in your software, no further action is required.

1. The current release comes with a technical note, model coefficients, downloadable software, mobile applications, test values and instructions to update your WMM software.

2. We updated the NOAA geomagnetic field calculators to use WMM2015v2.

3. We updated the WMM website with the new global maps of magnetic field components developed from WMM2015v2.

For many users, updating the WMM software is as simple as replacing the old “WMM.COF” file with the new “WMM.COF” file, and testing the updated software with the new test values. This out-of-cycle update is primarily intended for WMM customers operating in areas where the WMM performance is degraded (in the Arctic region).

To download the model, software or technical report, visit https://www.ngdc.noaa.gov/geomag/WMM/. While doing so, we request that you complete the survey page. Your feedback will strengthen the World Magnetic Model program.

Questions and comments may be addressed to geomag.models@noaa.gov.

 

[Andris]

Thanks Derez for being so vigilant!

 

[derez]

A new WMM.COF file is attached in the first post, valid until end of 2024.

 

[derez]

The WMMC.COF in the first post is replaced after change of format to comma-seperated, like the previous file.

 

[derez]

A letter from NOAA received on 17/12/21, there is a link inside to read the report :

Dear World Magnetic Model users,



This is a message from NOAA’s National Centers for Environmental Information. We are excited to announce the release of the “State of the Geomagnetic Field, December 2021” report. In this report, the performance of the World Magnetic Model 2020 (WMM2020) was assessed by comparing its predictions at 2022-01-01 with that of a more recent model inferred from data collected by the European Space Agency Swarm satellites until September 2021. For all magnetic field components, the WMM2020 global root-mean-square error increased by less than 1.5% over the past two years and remained well below the maximum error allowed by the U.S. Department of Defense WMM specification. The report also includes an assessment of the WMM secular variation, and descriptions of noteworthy changes in the Earth's main magnetic field, including magnetic pole drifts and the deepening of the South Atlantic Anomaly. The complete report can be accessed here.



Going forward, we plan to update this report on an annual basis, except for the years when we release a new World Magnetic Model.



Note that we did not update the World Magnetic Model. No action is required at this point of time to update WMM in your system. The next regular update of WMM will happen in December 2024.

 

[Andris]

A letter from NOAA received on 17/12/21, there is a link inside to read the report :

Keep up the good work @derez! We appreciate it.

 

[derez]

I got this message from MOAA:

Dear World Magnetic Model users,
This is a message from NOAA’s National Centers for Environmental Information. We are excited to announce the release of the “State of the Geomagnetic Field, December 2022” report. In this report, the performance of the World Magnetic Model 2020 (WMM2020) was assessed by comparing its predictions at 2023-01-01 with that of a more recent model inferred from data collected by the European Space Agency Swarm satellites until September 2022. For all magnetic field components, the WMM2020 global root-mean-square error increased by less than 5% over the past three years and remained well below the maximum error allowed by the U.S. Department of Defense WMM specification. The report also includes an assessment of the WMM secular variation, descriptions of noteworthy changes in the Earth's main magnetic field, including magnetic pole drifts and the deepening of the South Atlantic Anomaly and an assessment of the impact of strong to severe geomagnetic storms on WMM performance. The complete report can be accessed here.
We plan to update this report on an annual basis, except for the years when we release a new World Magnetic Model.
Note that we did not update the World Magnetic Model. No action is required at this point of time to update WMM in your system. The next regular update of WMM will happen in December 2024. If you have any questions, please contact geomag.models@noaa.gov.

Action - not required.

 

[derez]

A new WMMC.COF file is attached in the first post, valid until end of 2029.
I had to modify the new file from NOAA to have seperating commas like in the first file. Thanks to BlueVision who noticed it !!

Edit : corrected the end date...

 

[BlueVision]

A new WMMC.COF file is attached in the first post, valid until end of 2024.

Small correction: The file is valid until end of 2029 (as written in post #1, only a typo in post #35.