The earth has an ambient magnetic field which always has a 'north' in the ground. There's the north known as a direction, but the field also dips into the earth to varying degrees.

The idea is to have a simple magnetic detector fuse that detects this ambient magnetic field, and can count the peaks as the fuse is rotated on its way to the target.

Since the distance traveled is the same per rotation, regardless of forward velocity, an accurate turn-count fuse allows for precision air-bursting muntions.

The turn-count fuzes in current use, such as the Diehl ABM, use a micromechanical device to detect this, requiring advanced technologies.

Using an external reference that is universally present, such as the earths dip field, may greatly simplify fuse design.

I would suggest including a filtering to the fuse to prevent passage near powerlines or large metal objects from causing false counts. Such filtering might be using a timer that counts how long it takes to for the first two peaks to be counted, then only allows measurements during a narrow time-frame based around that initalization.

The earth has an ambient magnetic field which always has a 'north' in the ground. There's the north known as a direction, but the field also dips into the earth to varying degrees.

The idea is to have a simple magnetic detector fuse that detects this ambient magnetic field, and can count the peaks as the fuse is rotated on its way to the target.

Since the distance traveled is the same per rotation, regardless of forward velocity, an accurate turn-count fuse allows for precision air-bursting muntions.

The turn-count fuzes in current use, such as the Diehl ABM, use a micromechanical device to detect this, requiring advanced technologies.

Using an external reference that is universally present, such as the earths dip field, may greatly simplify fuse design.

I would suggest including a filtering to the fuse to prevent passage near powerlines or large metal objects from causing false counts. Such filtering might be using a timer that counts how long it takes to for the first two peaks to be counted, then only allows measurements during a narrow time-frame based around that initalization.

The earth has an ambient magnetic field which always has a 'north' in the ground. There's the north known as a direction, but the field also dips into the earth to varying degrees.

The idea is to have a simple magnetic detector fuse that detects this ambient magnetic field, and can count the peaks as the fuse is rotated on its way to the target.

Since the distance traveled is the same per rotation, regardless of forward velocity, an accurate turn-count fuse allows for precision air-bursting muntions.

The turn-count fuzes in current use, such as the Diehl ABM, use a micromechanical device to detect this, requiring advanced technologies.

Using an external reference that is universally present, such as the earths dip field, may greatly simplify fuse design.

I would suggest including a filtering to the fuse to prevent passage near powerlines or large metal objects from causing false counts. Such filtering might be using a timer that counts how long it takes to for the first two peaks to be counted, then only allows measurements during a narrow time-frame based around that initalization.

I don't think this is going to work.

The barrel will be steel, as will the case of any airburst munition. The angle of firing will be different, and the trajectory changes during the flight.

The main issue is the rate of rotation is far too high for most field strength detectors, thousands of times a second, which is far higher than the sample rate of any chip I have ever seen. And it is a tiny signal.

What's wrong with the far simpler time of flight calculation? Drop in an accelerometer if you want amazing accuracy, otherwise use a basic timer circuit to detonate after the right time at the speed of travel.

It could be measured by a magnetic or optical sensor in the round from a couple of marks on the barrel's muzzle. A basic circuit could do that, then feed a microprocessor or whatever to determine the flight time to the target. That would be very accurate.

EDIT: I think this would only work on the north/south line, or at 45 to each side. If you fired it east to west, you wouldn't get a detection event, as there is no dip to see. If you turned it round so it did do that, you would get two detects... I think... I'm not sure - I'm tired as it is late. I'll have a think about it till tomorrow.

I don't think this is going to work.

The barrel will be steel, as will the case of any airburst munition. The angle of firing will be different, and the trajectory changes during the flight.

The main issue is the rate of rotation is far too high for most field strength detectors, thousands of times a second, which is far higher than the sample rate of any chip I have ever seen. And it is a tiny signal.

What's wrong with the far simpler time of flight calculation? Drop in an accelerometer if you want amazing accuracy, otherwise use a basic timer circuit to detonate after the right time at the speed of travel.

It could be measured by a magnetic or optical sensor in the round from a couple of marks on the barrel's muzzle. A basic circuit could do that, then feed a microprocessor or whatever to determine the flight time to the target. That would be very accurate.

EDIT: I think this would only work on the north/south line, or at 45 to each side. If you fired it east to west, you wouldn't get a detection event, as there is no dip to see. If you turned it round so it did do that, you would get two detects... I think... I'm not sure - I'm tired as it is late. I'll have a think about it till tomorrow.

I don't think this is going to work.

The barrel will be steel, as will the case of any airburst munition. The angle of firing will be different, and the trajectory changes during the flight.

The main issue is the rate of rotation is far too high for most field strength detectors, thousands of times a second, which is far higher than the sample rate of any chip I have ever seen. And it is a tiny signal.

What's wrong with the far simpler time of flight calculation? Drop in an accelerometer if you want amazing accuracy, otherwise use a basic timer circuit to detonate after the right time at the speed of travel.

It could be measured by a magnetic or optical sensor in the round from a couple of marks on the barrel's muzzle. A basic circuit could do that, then feed a microprocessor or whatever to determine the flight time to the target. That would be very accurate.

EDIT: I think this would only work on the north/south line, or at 45 to each side. If you fired it east to west, you wouldn't get a detection event, as there is no dip to see. If you turned it round so it did do that, you would get two detects... I think... I'm not sure - I'm tired as it is late. I'll have a think about it till tomorrow.

Might such a thing be used specificially to target power plants and such that produce large magnetic distortions?

Somewhere out there the federal agent assigned to monitor this site has urgently faxed a dispatch to his contacts at DOD to check with some scientists to see if this is feasable. Hello agent Bob :)

Might such a thing be used specificially to target power plants and such that produce large magnetic distortions?

Somewhere out there the federal agent assigned to monitor this site has urgently faxed a dispatch to his contacts at DOD to check with some scientists to see if this is feasable. Hello agent Bob :)

Might such a thing be used specificially to target power plants and such that produce large magnetic distortions?

Somewhere out there the federal agent assigned to monitor this site has urgently faxed a dispatch to his contacts at DOD to check with some scientists to see if this is feasable. Hello agent Bob :)

Mega I think that there is acctually a multiple rocket launcher system armed with rockets having similar system as warhead guidance. It is designed for longrange tank combat. Work similar to anti-radar rocket. Launch, parachute opens at highest point of trajectory, little gliding till sensor lock on large metalic moving object, secondary buster rocket ignition and tank get its cumulative panzer-piercing charge at turet opening hatch which is one of the armor weak points. Bad day for armor divison in attack. Yes Bob, it can be made to work:)

Mega I think that there is acctually a multiple rocket launcher system armed with rockets having similar system as warhead guidance. It is designed for longrange tank combat. Work similar to anti-radar rocket. Launch, parachute opens at highest point of trajectory, little gliding till sensor lock on large metalic moving object, secondary buster rocket ignition and tank get its cumulative panzer-piercing charge at turet opening hatch which is one of the armor weak points. Bad day for armor divison in attack. Yes Bob, it can be made to work:)

Mega I think that there is acctually a multiple rocket launcher system armed with rockets having similar system as warhead guidance. It is designed for longrange tank combat. Work similar to anti-radar rocket. Launch, parachute opens at highest point of trajectory, little gliding till sensor lock on large metalic moving object, secondary buster rocket ignition and tank get its cumulative panzer-piercing charge at turet opening hatch which is one of the armor weak points. Bad day for armor divison in attack. Yes Bob, it can be made to work:)

Could be useful for taking down powerlines, too. Anything that gives off a large magnetic field due to the flow of electric inside could be targeted.

Could be useful for taking down powerlines, too. Anything that gives off a large magnetic field due to the flow of electric inside could be targeted.

Could be useful for taking down powerlines, too. Anything that gives off a large magnetic field due to the flow of electric inside could be targeted.

How about as a proximity detector for helicopters? A metallic object suspended in mid-air has to have a magnetic field or some distortion effect on the ambient earth field.

How about as a proximity detector for helicopters? A metallic object suspended in mid-air has to have a magnetic field or some distortion effect on the ambient earth field.

How about as a proximity detector for helicopters? A metallic object suspended in mid-air has to have a magnetic field or some distortion effect on the ambient earth field.

I think that helicopters are easier to take down with IR guided rockets but it can be good idea to try this one.

Few days ago I look at Discovery channel and saw interesting system. It isn't like this one, but it is close. Shell is fired from a cannon, it splits up in two parts that are NIR guided missiles for tank combat I think. It caught my attention:). Maybe OT but...I have to share it with you guys.

I think that helicopters are easier to take down with IR guided rockets but it can be good idea to try this one.

Few days ago I look at Discovery channel and saw interesting system. It isn't like this one, but it is close. Shell is fired from a cannon, it splits up in two parts that are NIR guided missiles for tank combat I think. It caught my attention:). Maybe OT but...I have to share it with you guys.

I think that helicopters are easier to take down with IR guided rockets but it can be good idea to try this one.

Few days ago I look at Discovery channel and saw interesting system. It isn't like this one, but it is close. Shell is fired from a cannon, it splits up in two parts that are NIR guided missiles for tank combat I think. It caught my attention:). Maybe OT but...I have to share it with you guys.

Electric field might be best for tracking a helicopter. Magnetic may well be too short range.

After several minutes in the air, those rotating parts and the friction against the air mean that there is a charge built up. There used to be guidance saying that the sling should touch down before being caught, to avoid static shock to the catcher. Not sure if this is still true, though.

If I had an E-field meter, it would be easy to see when the police helicopter flies over...

Electric field might be best for tracking a helicopter. Magnetic may well be too short range.

After several minutes in the air, those rotating parts and the friction against the air mean that there is a charge built up. There used to be guidance saying that the sling should touch down before being caught, to avoid static shock to the catcher. Not sure if this is still true, though.

If I had an E-field meter, it would be easy to see when the police helicopter flies over...

Electric field might be best for tracking a helicopter. Magnetic may well be too short range.

After several minutes in the air, those rotating parts and the friction against the air mean that there is a charge built up. There used to be guidance saying that the sling should touch down before being caught, to avoid static shock to the catcher. Not sure if this is still true, though.

If I had an E-field meter, it would be easy to see when the police helicopter flies over...

Another point to consider is that even if magnetic guidance for targetting helicopters is technically inferior to IR guidance, it is still a valuable tool, because it won't be expected. The very fact that it's inferior, means that they will expect the superior IR-based system, and possibly have counter-measures in place for it. The magnetic system, due to it's technical inferiority will provide the element of surprise.

Another point to consider is that even if magnetic guidance for targetting helicopters is technically inferior to IR guidance, it is still a valuable tool, because it won't be expected. The very fact that it's inferior, means that they will expect the superior IR-based system, and possibly have counter-measures in place for it. The magnetic system, due to it's technical inferiority will provide the element of surprise.

Another point to consider is that even if magnetic guidance for targetting helicopters is technically inferior to IR guidance, it is still a valuable tool, because it won't be expected. The very fact that it's inferior, means that they will expect the superior IR-based system, and possibly have counter-measures in place for it. The magnetic system, due to it's technical inferiority will provide the element of surprise.

Exactly!

Apaches and Blackhawks have IR decoys and flare launchers and all that shit. But point detonated RPG's have taken both of these birds down! :p

And what kind of ECM could there be for a magnetic field? I know you can degauss a ship, but can you do that for a helicopter made of composites?

Exactly!

Apaches and Blackhawks have IR decoys and flare launchers and all that shit. But point detonated RPG's have taken both of these birds down! :p

And what kind of ECM could there be for a magnetic field? I know you can degauss a ship, but can you do that for a helicopter made of composites?

Exactly!

Apaches and Blackhawks have IR decoys and flare launchers and all that shit. But point detonated RPG's have taken both of these birds down! :p

And what kind of ECM could there be for a magnetic field? I know you can degauss a ship, but can you do that for a helicopter made of composites?

Only thing I can see that makes this good idea is if it can be make to work it will make helicopter producers to start using other materials as titanium, aluminium etc. (as it already happens with submarines) making it harder/expensive to produce and it still won't make them "immortal" as NBK2000 already mentioned. The bigger they are...harder they fall. But anyway there is not such thing as invisibility shield (unless you are a spirit but then you couldn't care less for the earthly problems;)). Hell if I was looking for a low cost system for anti-helicopter rocket I would try sound detector (most of those noisy things are subsonic aren't they?) and I think it wouldn't be to hard to design system that would look for the frequency of helicopter rotating blade. Then you only need couple of those detectors per rocket little of phase or of centered for a triangulation of helicopter position, set it to detonate at certain proximity of sound source and that should do the job. You could even make system that would lock the target by using directed microphone for the target locking before launch. This could be made as double use system for the infantry making no difference between the tank or helicopter as long as it is in range. I must go to the radio and spare electronic parts shop this days anyway on the other matter, so I will see can an amateur done that in his backyard.

Only thing I can see that makes this good idea is if it can be make to work it will make helicopter producers to start using other materials as titanium, aluminium etc. (as it already happens with submarines) making it harder/expensive to produce and it still won't make them "immortal" as NBK2000 already mentioned. The bigger they are...harder they fall. But anyway there is not such thing as invisibility shield (unless you are a spirit but then you couldn't care less for the earthly problems;)). Hell if I was looking for a low cost system for anti-helicopter rocket I would try sound detector (most of those noisy things are subsonic aren't they?) and I think it wouldn't be to hard to design system that would look for the frequency of helicopter rotating blade. Then you only need couple of those detectors per rocket little of phase or of centered for a triangulation of helicopter position, set it to detonate at certain proximity of sound source and that should do the job. You could even make system that would lock the target by using directed microphone for the target locking before launch. This could be made as double use system for the infantry making no difference between the tank or helicopter as long as it is in range. I must go to the radio and spare electronic parts shop this days anyway on the other matter, so I will see can an amateur done that in his backyard.

Only thing I can see that makes this good idea is if it can be make to work it will make helicopter producers to start using other materials as titanium, aluminium etc. (as it already happens with submarines) making it harder/expensive to produce and it still won't make them "immortal" as NBK2000 already mentioned. The bigger they are...harder they fall. But anyway there is not such thing as invisibility shield (unless you are a spirit but then you couldn't care less for the earthly problems;)). Hell if I was looking for a low cost system for anti-helicopter rocket I would try sound detector (most of those noisy things are subsonic aren't they?) and I think it wouldn't be to hard to design system that would look for the frequency of helicopter rotating blade. Then you only need couple of those detectors per rocket little of phase or of centered for a triangulation of helicopter position, set it to detonate at certain proximity of sound source and that should do the job. You could even make system that would lock the target by using directed microphone for the target locking before launch. This could be made as double use system for the infantry making no difference between the tank or helicopter as long as it is in range. I must go to the radio and spare electronic parts shop this days anyway on the other matter, so I will see can an amateur done that in his backyard.

I found this snippet in a defense symposium proceedings.

The circuit can detect to a resolution of 1.5°, which should be more than adequate.

And, given 3 axis counting, plenty of anti-falsing, so large ferrous bodies should have no effect on the accuracy of the count fuze. :)

nbk, magnetic tracking wouldn't work because of too much ambient interference, however, magnetic proximity fuzes were all the rage in WW2. Most flak shells used them, allied and axis. Get a big enough charge with plenty of fragmentation on the end of a rocket and presto! optical sights would work fine for helicopters, they're nice and slow!