SKY LUMINANCE MAPPING SYSTEM AND MAPPING METHOD

摘要

A sky luminance mapping system includes a camera unit, two pyranometer units and a processing unit. Camera unit includes a fisheye lens to shoot image of sky dome and is equipped with light-shading devices which block the sun from the camera unit corresponding to instant location of the sun at instant time. First pyranometer unit measures daylight illuminance from the sky dome and outputs first intensity signal while the light-shading device is applied to block the sun. Second pyranometer unit measures daylight illuminance from the sky dome and outputs second intensity signal without blocking the sun. A reference intensity value is obtained by subtracting a value of the first intensity signal from a value of the second intensity signal. According to the value of the first intensity signal and the reference intensity value, a total luminance of and the luminance distribution in the image of the sky dome are corrected.

主权项

1. A sky luminance mapping system comprising:
a camera unit comprising:
a first support mechanism;a digital camera arranged on the first support mechanism, the digital camera having a fisheye lens to shoot an image of a sky dome; anda first light-shading device arranged on the first support mechanism, a location of the first light-shading device corresponding to an instant location of a sun at an instant time, such that the first light-shading device blocks the sun from the digital camera; a first pyranometer unit comprising:
a second support mechanism;a first pyranometer arranged on the second support mechanism, the first pyranometer measuring the daylight illuminance from the sky dome to output a first intensity signal; anda second light-shading device arranged on the second support mechanism, a structure of the second light-shading device being the same as a structure of the first light-shading device, a location of the second light-shading device corresponding to the instant location of the sun at the instant time, such that the second light-shading device blocks the sun from the first pyranometer, wherein the second support mechanism and the second light-shading device corresponding to the first support mechanism and the first light-shading device are separately arranged, or the second support mechanism and the second light-shading device are common devices used as the first support mechanism and the first light-shading device; a second pyranometer unit comprising:
a third support mechanism; anda second pyranometer arranged on the third support mechanism, the second pyranometer measuring the daylight illuminance from the sky dome to output a second intensity signal while the sun is not being blocked; and a processing unit, receiving the first intensity signal output by the first pyranometer, the second intensity signal output by the second pyranometer, and the image of the sky dome shot by the digital camera, wherein a reference intensity value is obtained by subtracting a value of the first intensity signal from a value of the second intensity signal, and a total luminance of and the luminance distribution in the image of the sky dome are corrected according to the value of the first intensity signal and the reference intensity value.