I told ya

[ivconic]

In 2003, New Scientist reported that induced magnetic fields had been found in the ocean, from space.
Then, on 11 April 2018, European Space Administration revealed that changing magnetic fields in the ocean measured 2.0-2.5nT at satellite altitude and provided a video of their activity on a planetary scale.
This article may be the first publication of provisional results on the ground and suggest that various further experiments may be worthwhile.

https://www.newscientist.com/article...flow-revealed/

[ivconic]

I hate to say I told ya...
...
For years, I have been repeating the same story about something that is directly related to this and has a radical impact on our hobby, directly on the work of metal detectors...
I probably have at least 50 posts, scattered across many forum topics, where I wrote the same thing. No one ever paid attention to those posts. There was not ONE reaction... all these years.
You cannot fully understand the behavior of metal detectors in real conditions without knowing about this process.
Of course, you will already know everything and much more about the operation of metal detectors... in the simulator, of course.
I rest my case...

[ivconic]

Page put in PDF:

[PICON]

Hi ivconic,


“For years, I have been repeating the same story about something that is directly related to this and has a radical impact on our hobby, directly on the work of metal detectors...
I probably have at least 50 posts, scattered across many forum topics, where I wrote the same thing. No one ever paid attention to those posts. There was not ONE reaction... all these years.
You cannot fully understand the behavior of metal detectors in real conditions without knowing about this process.
Of course, you will already know everything and much more about the operation of metal detectors... in the simulator, of course.
I rest my case...”

How do you perceive that this will impact on our hobby?

[Qiaozhi]

The article also says that these induced fields are tiny compared to the Earth’s overall field, which is 6000 times stronger.
The publication date is in 2003. 21 years ago.

[moodz]

I hate to say I told ya...
...
For years, I have been repeating the same story about something that is directly related to this and has a radical impact on our hobby, directly on the work of metal detectors...
I probably have at least 50 posts, scattered across many forum topics, where I wrote the same thing. No one ever paid attention to those posts. There was not ONE reaction... all these years.
You cannot fully understand the behavior of metal detectors in real conditions without knowing about this process.
Of course, you will already know everything and much more about the operation of metal detectors... in the simulator, of course.
I rest my case...

NO way ....

man made power distribution is much worse source of noise and that has not affected well designed machines. ( and then there is lightning .. The average positive ground flash has roughly double the peak current of a typical negative flash, and can produce peak currents up to 400 kA and charges of several hundred coulombs. ... )

[ivconic]

[ivconic]

The article also says that these induced fields are tiny compared to the Earth’s overall field, which is 6000 times stronger.
The publication date is in 2003. 21 years ago.

Then, on 11 April 2018, European Space Administration revealed that changing magnetic fields in the ocean measured 2.0-2.5nT at satellite altitude and provided a video of their activity on a planetary scale....

[ivconic]

To all this should be added the influence of solar storms, which do not have predictable behavior and intensity.
Which have the double effect of "swamping" the thin signal of the target in the soil.
Direct and indirect because the same storms affect the magnetic changes of large water bodies such as oceans at the same time.
As well as direct impact on the soil in which the targets are.
...
Folks, I've been observing this for decades, these are not isolated excesses.
It's a cyclical process that happens all the time.
Drastic changes were noticeable within one day.
...
Moodz most sites are very far from urban areas and industrial noise. In many such places I don't even have a GSM signal.
And you in Australia should be aware of this even more because you are surrounded by oceans and seas.
The only logical explanation why you don't accept this can be that you constantly go with the detector around transformer stations and search there... or you never go with the detector outside the workshop, anywhere!?
There is no other explanation!

[ivconic]

Let's establish some basic knowledge, okay?
The TX produces a strong magnetic field around the coil... and that's the part of the story that matters less here.
What happens in the RX coil? Under the influence of TX, an alternative magnetic field is created in the RX coil, much less powerful.
The focus is on that RX coil alternating magnetic field. Which is very weak and lasts a very short time, rapidly decreasing/decaying in strength.
It is the center of the whole story.
Any external influence will have a radical impact on the properties of that alternative magnetic field.
Shall I rest my case again?

[ivconic]

... What happens in the RX coil? Under the influence of TX, an alternative magnetic field is created in the RX coil, much less powerful...

Should be: " an alternative magnetic field is created in the target and picked up by the RX coil..."
Error in explanation because I was writing half asleep.
But the point is clear.
The so-called "target signal" is actually an alternating magnetic field on the target that has a very short half-life and a rapid decay.
The RX coil should pick up as much of that "information" as possible in order to have the clearest picture of the detected target.
And external influences certainly have a serious impact on that.

[moodz]

Should be: " an alternative magnetic field is created in the target and picked up by the RX coil..."
Error in explanation because I was writing half asleep.
But the point is clear.
The so-called "target signal" is actually an alternating magnetic field on the target that has a very short half-life and a rapid decay.
The RX coil should pick up as much of that "information" as possible in order to have the clearest picture of the detected target.
And external influences certainly have a serious impact on that.

Well two points ...

1. Telling us about the change in earth magnetic field is like telling us we are all going to die one day .... guess what we are.

2. The change in the mag field is in a different frequency spectrum from the TX/RX signal. I guess you are a time domain guy

[ivconic]

I have no comment on such outbursts...

[moodz]

Pretty much like your outbursts but I get straight to the point.

[ivconic]

You better go back to your simulator and continue playing with math and drawing various oscillograms.
This is a topic for real and serious detectorists, not video game fans.
If you noticed; I have long stopped visiting the meaningless theoretical self-indulgent self-centered floods of "I know everything"-obsessed diarrhea... that you started on the forum.
So it would be polite of you not to barge in here uninvited and act like a circus clown.
That would be the bare minimum of decency on your part.