Radar transmits pulses of radio waves or microwaves that reflect off any object in their path. The reflected waves are detected by the radar receiver, which uses the information to calculate the position, speed, and other characteristics of the object.
Radar can be used to detect objects on the ground, in the air, or in space. It is most commonly used to detect aircraft, but can also be used to detect ships, vehicles, weather features, birds, and even celestial bodies such as planets and stars.
Radar is a powerful tool, but it has some limitations. It can be affected by atmospheric conditions, terrain, and other objects in the vicinity of the target. Radar also has a limited range, which depends on the power of the radar transmitter. Also factor is size of the target radar is tracking.
How Does Radar See a Bullet
The radar signal that is reflected off of an object is usually relative to the size of the said object. So, for example, a bullet would register on a radar in a similar way to how a very stealthy plane would– though it does not mean the aircraft is undetectable. Rather, you wouldn’t be able to get any sort of usable information about the target at any distance.
Radar cross sections are not exclusive to bullets and planes or any other projectiles—storms, animals, and other objects can have them too. They will all add “noise” that will make finding the bullets very small signature hard to find.
So it’s not that radar systems can’t see bullets; it’s more that if you raise the sensitivity to detect bullets, it transforms into weather radar and you can’t tell what’s a bullet and what’s a cloud.
The distances bullets travel compared to radar range and accuracy are thus of little use. Even for a short-range radar system, you’ll pick up birds and other objects. Then there’s the issue of radars’ reaction times; a very fast radar would be needed as most can’t look all over at once.
Projectile Size Matters
So radar can detect projectiles like bullets and sometimes it is used for that purpose. Radars are used in a variety of ways to fire control systems (meaning, to see if your artillery fire is where it should be).
The availability of those systems is limited to heavier ordnance because the radar signature of 155mm shells, mortar rounds, and MLRS unguided rockets is very small. While there are several systems that detect small arms fire, they are mostly based on detecting the shockwave passing through the air. Another limiting factor is size and price.
Detection capabilities of the Israeli Iron Dome antimissile system, for example, are based on radars. The US/Israel joint experimental THEL defensive laser system is another example.
The aforementioned system is geared towards DIY MLRS rockets (particularly because that’s what most of the Israel-Palestine border assaults are using, but also because a big antimissile to shoot down a mortar shell is not really feasible tactically / economically). The former technology isn’t yet operational, but it has shown the ability to defeat many 90mm mortar shells fired into its engagement zone in quick succession.
Doppler Rader Technology for Wound Ballistics
To see if Doppler radar could provide more accurate readings of velocity and direction for bullets, anesthetized pigs were shoe from 9-10 meters away and measured the results with both Doppler radar and photocells.
The data from the two types of equipment was compared. An excellent correspondence was found between low, medium, and high-velocity bullet entry speeds, with an average variation of less than 1% (range 0-2%).
The correlation between overall accuracy and exit velocity was good, but the consistency of measurements at various distances is too poor. Because of signal cluttering due to tissue fragments released from the exit wound and bullet deflection, measurements of high-velocity bullets were difficult in both systems.
To measure the bullet’s movement, a Doppler radar was used to track its travel and determine its speed. They were able to construct a system that could follow even tiny caliber bullets for up to 15-20 meters.
The yaw angle could be detected even with smaller calibers, and the radar wasn’t bothered by other equipment closeby. Doppler radar is beneficial because it’s easy to set up, there is minimal risk of damage from stray bullets, and it gives very accurate measurements.
So far, there are positive results in measuring yaw angles of bullets to determine the point of stability. However, more research is needed before the measurement of the angle of yaw is more precise.
