Radar Guns
- Thread starter FrozenRope
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I know it depends on the Radar Gun, but the pocket radar manual says it will register lower speeds if your at an angle. It says for true speed reading to be directly in path with ball flight, as close as you can be. It says to think of it like holding a flashlight, you want to shine it beam directly at the ball no angles.
For pocket radar it shows standing behind the pitcher (fastpitch) and have gun aimed at release point. I haven't tried it this way yet. I just got the PR so I'll be experimenting with it. It also says that some balls register better then others. It doesn't say which balls tho.
I'll probably even try Grandpa Radar technique just for fun.
I hate tacos- said no Juan anywhere
For our use, we just try to make sure the radar gun is in a constant location. Honestly, and again this is just me, I don't really care about the exact speed (to an extent). But I want to know how each pitch changes; ie, the differential between fastball and off speed, or pitcher A vs pitcher B. Placing the gun in a fixed position, either on a tripod or on the fence seems to be the best recipe for success.
- Dec 11, 2010
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Here is a good explanation of consign effect or what some call "angle of radar wave deflection". It includes some nice graphics.
http://www.sportsradargun.com/pdf/COSINEEFFECTDETAILS.pdf
This paragraph is "nice to know" info. Skip ahead if you want the " cut to the chase" info.
Really simply, Doppler radar works like this: It sends out radar waves. Those waves are reflected back to the unit by moving objects. The unit measures the difference in time that it takes for those waves to be reflected back and makes a calculation based on that to determine the speed of the moving object. This measurement of the change in time it takes for the wave to be reflected is Doppler effect.
Two big things effect the measured speed of an object in motion. The first is the angle of the radar gun in relation to the object in motion. The closer you can be to having the object moving directly toward or away from where the radar is the more accurate the speed will be. In other words, the more "off to the side" the radar is the lower the speed reading will be. Keep in mind that as long as you are diligent about being fairly close to being directly in line with the object, this lower speed will be minimal. Like tenths of a mph.
Secondly, and this is the big one IMHO. Stay with me on this one. The speed of an object in flight like a thrown object or projectile fired from a gun is constantly decelerating. It can not stay a constant speed or accelerate without an outside force being imparted during flight. It is not traveling the same speed at the catcher as it was when it left the pitchers hand. It is constantly decelerating. Hold that thought, add this one: A radar unit projects a cone shaped beam. It is smallest at the radar and bigger the farther you get from it. So keeping both of those things in mind, where is the speed of the ball being measured and how much of an angle is there between the radar and the thrown ball?
So two questions for the radar operator from that: is the speed of the ball being measured early in flight after release or later? Is that particular pitch moving directly toward or away from the radar unit?
So for the op: is the low pitch the pitch that is moving in the straightest line toward or away from the radar unit?
Try this: clock your pitcher from over the right shoulder of your catcher, the left shoulder of your catcher, the right shoulder of the pitcher and the left shoulder of your pitcher. Here Is my prediction assuming the ball is pitched at a constant speed from a rh pitcher: The highest speed read should be from over the right shoulder of the catcher on a pitch to the outside half of the plate for a rh batter. Why? That would be the location that the ball is traveling almost directly toward the radar and the cone shaped beam should be picking up the ball closer to release not closer to the catcher. Flip flop all that for a lh pitcher, fastest pitch measurement should be from over left shoulder of pitcher with a pitch on inside half to a rh batter.
I don't know how wide the beam of a pocket radar is. If it is wide, you might have the highest speed obtained by shooting from close to the pitcher. I also don't know if they read constant speed or highest speed read and if it's constant, how often that speed reading is updated. (Larger radars update every so many milliseconds.....)
Also, some radars display highest speed obtained. Mine all read in continuous mode and you can see the speed of the ball decrease in flight.
Good radars are consistent, even from unit to unit. From manufacturer to manufacturer. They will have a margin of error less than one mph. (I am not including cheapo sports radars in this statement. I do not consider pocket radar to be a cheapo sports radar btw and I would like to own one.) In other words, technique of operation will affect readings more than the brand of radar.
Shoot from a consistent location. Know that position of the radar and technique of operator will affect readings slightly. Maybe consider flip flopping position for left handers- put it on the arm side or vice verse whether you are on catcher or pitchers end of field.
http://www.sportsradargun.com/pdf/COSINEEFFECTDETAILS.pdf
This paragraph is "nice to know" info. Skip ahead if you want the " cut to the chase" info.
Really simply, Doppler radar works like this: It sends out radar waves. Those waves are reflected back to the unit by moving objects. The unit measures the difference in time that it takes for those waves to be reflected back and makes a calculation based on that to determine the speed of the moving object. This measurement of the change in time it takes for the wave to be reflected is Doppler effect.
Two big things effect the measured speed of an object in motion. The first is the angle of the radar gun in relation to the object in motion. The closer you can be to having the object moving directly toward or away from where the radar is the more accurate the speed will be. In other words, the more "off to the side" the radar is the lower the speed reading will be. Keep in mind that as long as you are diligent about being fairly close to being directly in line with the object, this lower speed will be minimal. Like tenths of a mph.
Secondly, and this is the big one IMHO. Stay with me on this one. The speed of an object in flight like a thrown object or projectile fired from a gun is constantly decelerating. It can not stay a constant speed or accelerate without an outside force being imparted during flight. It is not traveling the same speed at the catcher as it was when it left the pitchers hand. It is constantly decelerating. Hold that thought, add this one: A radar unit projects a cone shaped beam. It is smallest at the radar and bigger the farther you get from it. So keeping both of those things in mind, where is the speed of the ball being measured and how much of an angle is there between the radar and the thrown ball?
So two questions for the radar operator from that: is the speed of the ball being measured early in flight after release or later? Is that particular pitch moving directly toward or away from the radar unit?
So for the op: is the low pitch the pitch that is moving in the straightest line toward or away from the radar unit?
Try this: clock your pitcher from over the right shoulder of your catcher, the left shoulder of your catcher, the right shoulder of the pitcher and the left shoulder of your pitcher. Here Is my prediction assuming the ball is pitched at a constant speed from a rh pitcher: The highest speed read should be from over the right shoulder of the catcher on a pitch to the outside half of the plate for a rh batter. Why? That would be the location that the ball is traveling almost directly toward the radar and the cone shaped beam should be picking up the ball closer to release not closer to the catcher. Flip flop all that for a lh pitcher, fastest pitch measurement should be from over left shoulder of pitcher with a pitch on inside half to a rh batter.
I don't know how wide the beam of a pocket radar is. If it is wide, you might have the highest speed obtained by shooting from close to the pitcher. I also don't know if they read constant speed or highest speed read and if it's constant, how often that speed reading is updated. (Larger radars update every so many milliseconds.....)
Also, some radars display highest speed obtained. Mine all read in continuous mode and you can see the speed of the ball decrease in flight.
Good radars are consistent, even from unit to unit. From manufacturer to manufacturer. They will have a margin of error less than one mph. (I am not including cheapo sports radars in this statement. I do not consider pocket radar to be a cheapo sports radar btw and I would like to own one.) In other words, technique of operation will affect readings more than the brand of radar.
Shoot from a consistent location. Know that position of the radar and technique of operator will affect readings slightly. Maybe consider flip flopping position for left handers- put it on the arm side or vice verse whether you are on catcher or pitchers end of field.
Last edited:
- Dec 11, 2010
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- 113
More "nice to know" info:
Lighter objects in flight decelerate at a much higher rate than heavier objects.
A whiffle ball decelerates much faster than a stitched softball. A foam ball decelerates faster than a dimple pitching machine ball. Not important in the pitching section but maybe it is in a front toss batting discussion.
Lighter objects in flight decelerate at a much higher rate than heavier objects.
A whiffle ball decelerates much faster than a stitched softball. A foam ball decelerates faster than a dimple pitching machine ball. Not important in the pitching section but maybe it is in a front toss batting discussion.
- Jul 17, 2012
- 1,091
- 38
Westwind, I don't think that you'll see a measurable error from either shoulder of the catcher.....assuming you're only moving the gun 2 or 3 feet, that's less than a degree off of dead center, unless of course it's a wild pitch. 1% error doesn't kick in until you get to 8 degrees. I agree, opposite shoulder of the pitcher may get you a significant error, but not from behind the catcher. So in your example, I would expect the SAME reading from either shoulder of the catcher, and throwing shoulder of the pitcher. May get a slightly lower reading from the glove side of the pitcher.
- Dec 11, 2010
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- 113
I agree.
I doubt most radar users understand that that though. I see too many people trying to use radar wrong.
Consign, added to clocking the ball late in flight might very well the the 2-3 mph that drives a half loony pitchers parent over the edge, lol.
I have noticed this as well and that it is slower on high pitches. I can think of two explanations: 1) The Pocket Radar measures the fastest point which will be near release of the ball. The angle of release will be pointing more directly at the catcher when the ball is thrown into the dirt. To throw a strike the angle of release is pointing above the catchers head and on a high pitch even higher. The faster the pitch the less this has an effect but at 40 mph its noticeable. 2) If the catcher is holding the pocket radar then there could be an unintentional Grandpa Effect where as you reach down for a low pitch to the glove side your right hand holding the radar jerks forward.
It has nothing to do with the radar, it is because pitches thrown lower in the zone tend to yield higher velocity.
