Lasers can be used to determine the distance from an object, and this is the idea behind using a laser range finder. Such range finders are used in the military, forestry, sports and even as an alternative to measuring tapes.
How Do Laser Range Finders Work
The basic principle behind such laser range finders is the one of time of flight. A laser pulse is sent to the object whose distance from a point is to be measured, and gets reflected back to the point of origin. The time taken for the pulse to return is measured. Most such pulses are coded, so that they have a unique identity that cannot be jammed. Precision can be limited to millimeters depending on the speed of the measuring detector and the sharpness of the laser pulse. The calculation of the distance is a simple mathematical one that is linked to the speed of light. This requires timing measurements that are measured in nanoseconds, and thus needs fairly sophisticated circuitry.
Likely Problems in Laser Range Finders
While laser range finders can be largely depended on for fairly accurate results, they are sometimes affected by atmospheric distortions and likely divergence of the beam itself. The narrowness of the beam is affected by air and diverges as the object distance increases. This obscures the beam on its return and can result in errors. Wind and temperature can also affect laser beams, and thus the results from a laser range finder. Heat tends to bend laser beams, and in case the beam passes any source of heat it can go off target.
Technologies Used
The most common of these is the measurement of the time taken by the laser to travel to the object and back. Most laser range finders will fire a number of pulses in sequence and then work out the average time taken for the pulse to travel back. This is then averaged out to be converted into distance using the speed of light for the calculations. Other laser range finders measure the shift of the phases from multiple frequencies caused by the reflection and this generates a number of simultaneous equations that need to be solved to arrive at an answer. Interferometry is another technique in use for laser range finders.
Choosing the Right Laser Range Finder
A number of things need to be considered when you are contemplating buying a laser range finder. Besides the obvious price restraint, it is necessary to consider the magnification required, the range for which it is needed and any compensation features for accurate readings.
When you operate a laser range finder, you basically first need to pinpoint the object whose range you need to find. This can be done through magnification devices that bring the object into close view so that they are correctly targeted. Magnification of between four and eight are considered ideal for hunters, golfers and archery athletes.
Effective range can be the one in which you will get fairly accurate results. If the targets are larger, this maximum range can increase substantially. So the objects that are normally to be targeted have to be determined before you decide on effective range. Targeting an animal can be different from targeting large buildings or structures as surveyors would.
Angle compensation features come into play when the target is at a very steep angle from the viewing position. Under normal circumstances, such angle compensation may not be necessary for normal use.
How Do Laser Range Finders Work
The basic principle behind such laser range finders is the one of time of flight. A laser pulse is sent to the object whose distance from a point is to be measured, and gets reflected back to the point of origin. The time taken for the pulse to return is measured. Most such pulses are coded, so that they have a unique identity that cannot be jammed. Precision can be limited to millimeters depending on the speed of the measuring detector and the sharpness of the laser pulse. The calculation of the distance is a simple mathematical one that is linked to the speed of light. This requires timing measurements that are measured in nanoseconds, and thus needs fairly sophisticated circuitry.
Likely Problems in Laser Range Finders
While laser range finders can be largely depended on for fairly accurate results, they are sometimes affected by atmospheric distortions and likely divergence of the beam itself. The narrowness of the beam is affected by air and diverges as the object distance increases. This obscures the beam on its return and can result in errors. Wind and temperature can also affect laser beams, and thus the results from a laser range finder. Heat tends to bend laser beams, and in case the beam passes any source of heat it can go off target.
Technologies Used
The most common of these is the measurement of the time taken by the laser to travel to the object and back. Most laser range finders will fire a number of pulses in sequence and then work out the average time taken for the pulse to travel back. This is then averaged out to be converted into distance using the speed of light for the calculations. Other laser range finders measure the shift of the phases from multiple frequencies caused by the reflection and this generates a number of simultaneous equations that need to be solved to arrive at an answer. Interferometry is another technique in use for laser range finders.
Choosing the Right Laser Range Finder
A number of things need to be considered when you are contemplating buying a laser range finder. Besides the obvious price restraint, it is necessary to consider the magnification required, the range for which it is needed and any compensation features for accurate readings.
When you operate a laser range finder, you basically first need to pinpoint the object whose range you need to find. This can be done through magnification devices that bring the object into close view so that they are correctly targeted. Magnification of between four and eight are considered ideal for hunters, golfers and archery athletes.
Effective range can be the one in which you will get fairly accurate results. If the targets are larger, this maximum range can increase substantially. So the objects that are normally to be targeted have to be determined before you decide on effective range. Targeting an animal can be different from targeting large buildings or structures as surveyors would.
Angle compensation features come into play when the target is at a very steep angle from the viewing position. Under normal circumstances, such angle compensation may not be necessary for normal use.
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