LabRadar
- Thread starter Gregory Gauvin
- Start date
Doublehelix3216
New member
I am thinking that one of the reasons for the high cost of the Labradar is that they are the only product like it in the world that I know of. I am sure the technology is not cheap either, but when there is no competition, you can charge whatever you want.
I'll bet that someday, Caldwell or some other manufacturer will have a similar product, and then the costs will come down somewhat. It may come down to patent issues, and then of course the wait will be longer.
I'll bet that someday, Caldwell or some other manufacturer will have a similar product, and then the costs will come down somewhat. It may come down to patent issues, and then of course the wait will be longer.
There are numerous systems in industry and military applications that use the same, or substantially similar technology as LabRadar. But yes, the only one in the shooting sports market. I too suspect that will change, and it would not surprise me to see that change come in 2017. When the price comes down, I will reconsider.
I played with a system that used similar technology in 2008 that was built by a friend who is an engineer.
https://en.wikipedia.org/wiki/Continuous-wave_radar
He also built a 3'x3'x3' box that you shot 5 rounds through at 25, 50, 100, 200 and 400 yards and for that bullet and environment, you get an equation that is the dynamic BC of the bullet. It was cooler than cool and very cutting edge, but with the current solvers, there is really no way to utilize an equation, instead of a constant, in a solver. I am not sure if that will change or not, but there are some advanced systems that are attempting to use such an equation, especially for ELR shooting.
I played with a system that used similar technology in 2008 that was built by a friend who is an engineer.
https://en.wikipedia.org/wiki/Continuous-wave_radar
He also built a 3'x3'x3' box that you shot 5 rounds through at 25, 50, 100, 200 and 400 yards and for that bullet and environment, you get an equation that is the dynamic BC of the bullet. It was cooler than cool and very cutting edge, but with the current solvers, there is really no way to utilize an equation, instead of a constant, in a solver. I am not sure if that will change or not, but there are some advanced systems that are attempting to use such an equation, especially for ELR shooting.
There are lots of radar modules out there that are not expensive and are used in robotics. I haven't looked at the details to see how power levels compare. There is an FCC limit to the power of an unlicensed radar unit, and that's the only reason a version of the Labradar isn't available that can reach out two or three hundred yards, the way military and licensed industrial Doppler installations can.
I have to point out the Oehler 35P optical chronograph costs $595. The German Kurzzeit B19 optical chronograph is $1199. No quality instrument that is not made in China is inexpensive. The original pre-release price on the Labradar (made in Canada) was going to be about $100 lower than it currently is. I'm thinking they nudged it up to be $50 less than the Oehler, since it doesn't come with a stand or case like the Oehler does. That lets them recover some of the initial investment before the Chinese knock-off's show up. At that point I expect they'll come down a bit.
MarkCO,
The RSI Shooting lab lets you use custom drag functions. So does the QuickTARGET Unlimited software that comes with QuickLOAD. Indeed, it has hundreds of Lapua bullet individual drag coefficient tables based on Doppler radar readings, plus some tables the BRL created for bullets used by the military thirty years ago. With such a table, the bullet becomes its own reference projectile and is used a BC of 1.0000. Works fine.
I know Hornady now has a licensed Doppler unit that reaches out 300 yards, and is getting G1 BC's for their bullets from that. I am hoping they will eventually follow the example set by Lapua and convert that data to drag coefficient tables for their bullets that they publish.
I have to point out the Oehler 35P optical chronograph costs $595. The German Kurzzeit B19 optical chronograph is $1199. No quality instrument that is not made in China is inexpensive. The original pre-release price on the Labradar (made in Canada) was going to be about $100 lower than it currently is. I'm thinking they nudged it up to be $50 less than the Oehler, since it doesn't come with a stand or case like the Oehler does. That lets them recover some of the initial investment before the Chinese knock-off's show up. At that point I expect they'll come down a bit.
MarkCO,
The RSI Shooting lab lets you use custom drag functions. So does the QuickTARGET Unlimited software that comes with QuickLOAD. Indeed, it has hundreds of Lapua bullet individual drag coefficient tables based on Doppler radar readings, plus some tables the BRL created for bullets used by the military thirty years ago. With such a table, the bullet becomes its own reference projectile and is used a BC of 1.0000. Works fine.
I know Hornady now has a licensed Doppler unit that reaches out 300 yards, and is getting G1 BC's for their bullets from that. I am hoping they will eventually follow the example set by Lapua and convert that data to drag coefficient tables for their bullets that they publish.
ShootistPRS
New member
I have to ask whether the ability to track bullets at greater distance is due to the power of the unit or its operating frequency. As a rule your radar target must be larger than the wavelength in order to be seen.
Like stealth planes boat tail bullets and small calibers do not have large reflective surfaces and are harder to "see". As range increases the watt density decreases but a directed beam at 100 mW should have considerably more range than 200 yards.
Are there limitations on the frequency that can be used in the microwave segment of the radio bands?
Like stealth planes boat tail bullets and small calibers do not have large reflective surfaces and are harder to "see". As range increases the watt density decreases but a directed beam at 100 mW should have considerably more range than 200 yards.
Are there limitations on the frequency that can be used in the microwave segment of the radio bands?
The autonomous automobiles are using W band radar, which is in the 75-110 GHz range, with 4.0 mm to 2.7 mm wavelength, respectively. Small enough for airgun pellets. The beam shape on the Labradar is not too tight as the aiming device isn't too precise and the bullet has to be captured by the unit offset to the side of the gun. So the signal disperses fairly quickly. The power is limited by the FCC, which will allow some maximum number of microvolts per meter field strength at some distance from the transmitter.
ShootistPRS
New member
Unclenick,
I didn't do the calculation for wave length but the lab radar works at 24.080 to 24.168 GHz using 8 MHz band steps.
Off the top of my head isn't that close to 12mm? Or close to 0.5"...
I didn't do the calculation for wave length but the lab radar works at 24.080 to 24.168 GHz using 8 MHz band steps.
Off the top of my head isn't that close to 12mm? Or close to 0.5"...
Yes. 12.5 mm, give or take.
I pulled a lazy and didn't stop to check the Labradar frequency. I was just thinking of all the inexpensive radar transducers you can pick up now, some of which run pretty high up.
So, going back and thinking about reflection of waves, I recall the rule of thumb in UHF antenna design was to figure any grid smaller than a quarter wavelength would appear solid and serve as a reflecting surface. But the grid itself might be made up of hardware cloth or other mesh whose individual wires were a lot smaller in diameter than the openings, yet they still reflected the signal just fine. So I'm thinking the premise is wrong. A smaller-than-wavelength item can reflect, though it's likely partial and only during some phases of the wave, and the rest would refract around the bullet. But a partial reflection can still be detected.
I pulled a lazy and didn't stop to check the Labradar frequency. I was just thinking of all the inexpensive radar transducers you can pick up now, some of which run pretty high up.
So, going back and thinking about reflection of waves, I recall the rule of thumb in UHF antenna design was to figure any grid smaller than a quarter wavelength would appear solid and serve as a reflecting surface. But the grid itself might be made up of hardware cloth or other mesh whose individual wires were a lot smaller in diameter than the openings, yet they still reflected the signal just fine. So I'm thinking the premise is wrong. A smaller-than-wavelength item can reflect, though it's likely partial and only during some phases of the wave, and the rest would refract around the bullet. But a partial reflection can still be detected.
ShootistPRS
New member
Unclenick,
I agree that a grid of thin wire reflects because the holes are less than one wavelength and the entire grid is substantially larger.
The lab radar might get an echo off the shock wave that travels with the bullet too. That was one of the reasons the stealth fighter was kept subsonic.
The argument against that thought is that the radar will track an arrow, which clearly is never supersonic and has a small cross section.
So I don't understand radar as well as I thought I did.
Thank you for the very polite discussion.
I agree that a grid of thin wire reflects because the holes are less than one wavelength and the entire grid is substantially larger.
The lab radar might get an echo off the shock wave that travels with the bullet too. That was one of the reasons the stealth fighter was kept subsonic.
The argument against that thought is that the radar will track an arrow, which clearly is never supersonic and has a small cross section.
So I don't understand radar as well as I thought I did.
Thank you for the very polite discussion.
It's been 40 years since I even looked at a microwave lab and they didn't let me stay and play. I'm also remembering we always figured telescope mirrors to 1/4 wavelength, too, to prevent ghosting of virtual images seen through it. So I'm thinking 1/4λ is the actual critical value. Have to go back to a physics book to check on the wave mechanics involved. Time for a little homework.
A good discussion here. I appreciate the more in-depth discussion.
One thing that hasn't been mentioned are the limitations of the LabRadar. It has an upper velocity detection limit of 3,900 fps and has reported difficulty with detecting sub-22 caliber bullets. That's fine for 98% of us 99% of the time. But an Oehler 35P or Magnetospeed might be more suitable for those shooting loads exceeding 3,900 in 220 Swift, .22-250, .204 Ruger, .17 Rem. Fireball, .17 Rem, etc. or any possibly any load in 17-20 caliber firearms.
One thing that hasn't been mentioned are the limitations of the LabRadar. It has an upper velocity detection limit of 3,900 fps and has reported difficulty with detecting sub-22 caliber bullets. That's fine for 98% of us 99% of the time. But an Oehler 35P or Magnetospeed might be more suitable for those shooting loads exceeding 3,900 in 220 Swift, .22-250, .204 Ruger, .17 Rem. Fireball, .17 Rem, etc. or any possibly any load in 17-20 caliber firearms.
I've looked at a few documents on basics of RADAR and found that while direct reflection is limited to objects a wavelength or greater in size, sub-wavelength size items will still produce scattering. This is likely the actual reason for the ¼λ telescope mirror resolution. The scattering, through various filtering and software analysis techniques, can still produces information.
This is the best review I found on line so far. It gives some good hints for setup.
This is the best review I found on line so far. It gives some good hints for setup.
Bytesniffer
New member
How do u use Labrador at the range
When everyone is firing next to you and
All the targets are down range
Next to one another.
When everyone is firing next to you and
All the targets are down range
Next to one another.
Read the review I linked to. The bullets on adjacent points don't enter the radiation cone at a usable angle, and even if their sound should trigger it, the instrument doesn't pick up the bullet until way down range, so it ignores it.
I do advise a better aiming than the device comes with the unit (a little v-channel at the top). That article showed how to use a plastic square as a sighter, which I thought was a good idea. I went to a lot more trouble and turned a bore sighter holder for mine, then used it to check how well a small metal tube laid into that notch lined up with the laser point. I had to sand the notch in a little to get it right, and now I just keep the tube in the carrying case and lay it in the notch and try to center it on a point on the target that is about 6" above my mean point of aim (though it doesn't have to be that exact). But the square is a lot simpler and a tube can be glued to it without having to alter anything on the radar. I would recommend the square method and not wasting time with what I did. Sometimes it seems, having the tools, I take the complicated way out because I can.
I do advise a better aiming than the device comes with the unit (a little v-channel at the top). That article showed how to use a plastic square as a sighter, which I thought was a good idea. I went to a lot more trouble and turned a bore sighter holder for mine, then used it to check how well a small metal tube laid into that notch lined up with the laser point. I had to sand the notch in a little to get it right, and now I just keep the tube in the carrying case and lay it in the notch and try to center it on a point on the target that is about 6" above my mean point of aim (though it doesn't have to be that exact). But the square is a lot simpler and a tube can be glued to it without having to alter anything on the radar. I would recommend the square method and not wasting time with what I did. Sometimes it seems, having the tools, I take the complicated way out because I can.