The market space of the online business of green laser is still large enough

Returned from the target, the optical signal received by the scanning optical system and beam expander, the two-part optical receiver; T / R change-over switch will receive the optical signal into the mixer and local oscillator baseline optical signal mixer then focused on the detector amplified and converted into electrical signals by the imaging optical system; and high-pass filter to filter out the background and the local oscillator low-frequency signal; lidar measured target distance and speed information from the signal processor to extract. Bistatic laser radar by the separation of the beam expander and a scanning optical system composed of the receiver, eliminating the need for T / R change-over switch, the other is identical with the monostatic lidar. Laser radar range equation. It is commonly seen for green laser pointer .
Ranging equation formula. Monostatic and bistatic laser radar range equation, the general formula: where: laser power (W); distribution function for the beam; atmospheric transmittance for the transmitter to the target; transmitter optical system efficiency; φ is beam width or divergence (rad); transmitter to target distance (m); target laser cross section (m2); atmospheric transmittance for the target to the receiver; target to receiver distance (m); D, for the receive window diameter (m); receiver optical efficiency of the system; received power (W). The development of microwave radar, laser radar is the same location principle. The difference is that the microwave wavelength and beam width is much larger than the laser targeting error is very small; laser radar is the opposite.  green laser pointer can be used in the open air for irradiance during travel or camping of the customer.
For purposes of comparison, as shown in the microwave radar ranging equation: If the target angle width greater than the transmitter beam width in azimuth and elevation direction, the laser target cross section is proportional to the irradiated area, ie φ is 2 and R 2 is proportional to the beam distribution is approximately uniform Lambertian intensity distribution. The formula (1) can be simplified as: where: ρ is the reflection coefficient of the Lambertian target. Monostatic laser radar to target distance under the conditions of weak atmospheric attenuation, the maximum measured Chengjing Gong (1) transformation too. Transmitter characteristics. The transmitter characteristics of the beam distribution function, the beam width and pointing error, external factors. Beam forming and beam distribution function. Beam in the laser cavity, the lowest order mode (TEMoo) Gaussian mode. So the manufacturer should keep customer’s feedback towards green laser pointer  well in record.
If you ignore the pointing error of a uniform beam distribution to estimate the performance and power, the beam distribution function as follows: K (ψ, φ) =; where ψ is the pointing error; φ is the beam width (divergence). Airy function to describe the far-field beam distribution function as follows: where the first order Bessel function. With Gaussian intensity TEMoo mode of the distribution function: where, for the Gaussian beam waist radius. The beam width is a measure of launching a wide-angle beam distribution. Which conventional radar beam width, defined as the maximum value on the full-width (FWHM), it has nothing to do with the beam distribution. Laser radar beam width, optical experiments can accept a difference with conventional radar defined as follows: (1) diffraction-limited beam width. The customer can put forward the information of some parameters and performances of green laser pointer .
III transmitter pointing error pointing error of the air small targets. Air small targets such as a high-precision laser radar ranging, targeting error is small can be measured to the three-dimensional spatial location; slightly increased targeting error, even if accurately measured the radial distance will produce a horizontal distance error performance of the laser radar is usually by limit of atmospheric transmission performance. Atmospheric transmission performance can be calculated with Beer's law: where: atmospheric attenuation density. ; R is the laser radar to target distance; points for the distance variable; ω is the wavelength of the variable of integration; λ1 and λ2, respectively, for the shortest and longest wavelength. To simplify the formula for where α is the atmospheric attenuation constant atmospheric attenuation constant, the density in the whole optical spectral region. The market space of the online business of  green laser    is still large enough.