Close range shoots which laser jammers performs the best?

[afauzims]

At a close range shoot using Laser digicam (LTI Marksman) say 150 meter and below, which jammers will have a better coverage of detecting the laser shoot and how may head to be used for a typical medium car. Any suggestions guys?

[<<JAZZY>>]

http://guysoflidar.com/march-2007/la...mmer-test.html

[afauzims]

Thanks, but the tests was perform at 2,000 feet (600 meter) and straight road. In real situations, as for laser digicam (Marksman) the optimal range is only 50 to 125 meter (160 to 410 feet) and the beam from the laser gun is 5 – 14 in or less (3 feet wide at 1000 feet). The concept is ambush i.e. at corners, under and over bridge even at hilly side of the road. Sure are hard to beat.

Only if the tests are made to stimulate the real life driving situation, the result would be better e.g. so we can figure out how many heads to be used at a very closed range and the performance. ops:

[Mthman30]

Thanks, but the tests was perform at 2,000 feet (600 meter) and straight road. In real situations, as for laser digicam (Marksman) the optimal range is only 50 to 125 meter (160 to 410 feet) and the beam from the laser gun is 5 – 14 in or less (3 feet wide at 1000 feet). The concept is ambush i.e. at corners, under and over bridge ever at hilly side of the road. Sure are hard to beat.

Only if the tests are made to stimulate the real life driving situation, the result would be better e.g. so we can figure out how many heads to be used at a very closed range and the performance. ops:

I did some tests a month or two ago with a Marksman and tried some short engagements, around the corner shots etc. The jammer I tested was an Antilaser G8 dual head unit.

Until I did the tests I didn't think that the jammer would work as well on short term engagements as when targeting began at 2000FT. I was not a believer.

I was unable to get a reading no matter what I tried. My buddy thought for sure that on the off axis around the corner shot he'd be able to ambush me and get a reading. He couldn't. We were both amazed.

I'll be testing the unit again in the next few weeks with an LTI Ultralyte. The unit is now mounted on my new car, a 2007 Nissan Altima SE which is metallic grey. I will once again test the "real world" scenarios such as over the hill and around the corner.

I tried short term engagements on my brothers truck and could not get a lock.

Bottom line is that distance did not make a difference. I don't know how small the beam on the Marksman actually got, but it was obviously still wide enough to trigger the jammer, otherwise there would have been PT.

I was able to fool the Valentine 1 when shooting short range on fog lights or at the plate, but never the jammer.

My guess is that the beam will only get down to a certain size on some guns and never smaller.

I'd love to see an IR video of a variety of guns at say 100FT to see what the beam looked like in terms of size.

Does anyone have anything like that to post??

[jimbonzzz]

Thanks, but the tests was perform at 2,000 feet (600 meter) and straight road. In real situations, as for laser digicam (Marksman) the optimal range is only 50 to 125 meter (160 to 410 feet) and the beam from the laser gun is 5 – 14 in or less (3 feet wide at 1000 feet). The concept is ambush i.e. at corners, under and over bridge ever at hilly side of the road. Sure are hard to beat.

Only if the tests are made to stimulate the real life driving situation, the result would be better e.g. so we can figure out how many heads to be used at a very closed range and the performance. ops:

-There is NO difference in jamming capability regardless of when the vehicle is first targeted. For example, if a vehicle is first targeted at 2000 feet and jams to within 100 feet, then if the vehicle is first targeted at 500 feet it will also jam to within 100 feet.

-The beam widths you are referring to are expressed in FWHM (full width at half maximum) and most modern jammers are sensitive enough to detect the laser even if the heads are not directly targeted with the "hot part" of the beam (which is what one would see with an IR camera).

[fulcrum]

At close range, the amount of laserheads becomes the most important factor. Triple head in the front and rear.
At very close ranges also the jammer software could become a problem.

[repeter]

-There is NO difference in jamming capability regardless of when the vehicle is first targeted. For example, if a vehicle is first targeted at 2000 feet and jams to within 100 feet, then if the vehicle is first targeted at 500 feet it will also jam to within 100 feet.

I don't have any experience with jammers, but your example seems too general. Some of the jammers from the last GOL test would jtg in one round and get +500ft. pt in another round (made up numbers). I don't think you could predict the results of a 300ft. test given the previous results of the 2000ft. or am I missing something?

[jimbonzzz]

-There is NO difference in jamming capability regardless of when the vehicle is first targeted. For example, if a vehicle is first targeted at 2000 feet and jams to within 100 feet, then if the vehicle is first targeted at 500 feet it will also jam to within 100 feet.

I don't have any experience with jammers, but your example seems too general. Some of the jammers from the last GOL test would jtg in one round and get +500ft. pt in another round (made up numbers). I don't think you could predict the results of a 300ft. test given the previous results of the 2000ft. or am I missing something?

Some jammers were indeed inconsistent against some guns, which is why we do three run each. But you can expect the same level of inconsistency regardless of the distance the vehicle is first targeted. You CAN predict how they would perform in a 300-foot test. Given the same test conditions of course, if one waited until 300 feet to pull the trigger, you would expect almost immediate punchthrough on one run and JTG on another. So if one was looking for a jammer to protect against short 300-foot shots against this particular example gun, then this example jammer might not be a good choice, because it is inconsistent.

[fulcrum]

Often on this forum there is talk about laser beam width at a certain distance. At least as important is the (often ignored) receiver part of a lasergun and its high quality optics. An example might clarify this:

- Imagine a car at a distance of 300ft.
- The laserjammer is in the centre under the licence plate
- The lasergun is pointed at the far left of the left headlight
- We trigger the gun
- The jammer will be triggered (in most of the cases), because its receiver is very sensitive and a laser beam is always scattered a little bit. (Die structure of the laserdiode, optical imperfections of the lens and environmental factors)

- And this is the essence: The lasergun doesn’t SEE the jammer. It looks in a very small field of view. (Amout as small as the width of the laser beam) However smart the jammer software or powerful its laser. This jammer can not protect you.

This info is correct for at least one lasergun (JenOptic) that I tested; I connected an oscilloscope to the receiver signal of the gun pointed at an active pulse laser diode. This receiver field of view is real, and becomes more of a problem when the distance is smaller and the gun is pointed away from the jammer. (Worst case: Using a tripod)

Solution: More jammer heads

ONE of the reasons causing the inconsistencies in the GOL tests is this effect. Test the guns at short ranges from a tripod and you will be shocked! JTGs will become a lot less common. (Luckily tripods are not used that often in the real world)

Look at the size of the beam in these pictures and imagine a jammer on the left or right of this car. The gun will not "see" the jammer, and make an easy punch through.

[ELVATO]

From what I understand, jammer beams are divergent.