Study of the technique of 4-face coated pyramid prism for measurement of upper atmospheric wind field

The principle of measurement of upper atmospheric wind field has been described first by using the technique of 4-face coated pyramid prism (CPP). If the anti-r efraction films is coated by λ/4λwavelengthstepped optical path difference (OPD), there can be obtained 4 interference intensities for one fringe simultan eously to measure the upper atmospheric wind field. After correlative parameters of CPP technique are calculated, the CPP's vertex angle must be larger than 24 degree and the width of symmetric incident beam to CPP vertex may be less than 8 mm by LF7 prism and MgF2 anti-refraction films, so that it can be use d to dete ct the upper atmospheric wind for 9°×9° interferometer's field of view (FOV) and CCD 4.5°×4.5°. Finally, we made a simulation test for 2-face coated prism , two group of speckle patterns of deflection light and intensities on CCD have been obtained for prism vertex angle 60°　and °. By copying the two-speckl e patterns to obtain CPP's four ones, it can achieve “four intensities way" for upper atmospheric wind field measurement. The test result is made sure of this way to measure the atmospheric wind. This way has developed the technique of pas sive measurement of wind field.