國內氣象站需量測許多不同氣象數據，因此需在有限空間內安裝不同氣象儀器，而氣象站的地點也會因位處都市或山上而周圍環境可能才在有高樓大廈或林木等等，這些遮蔽物皆會在量測全日空日射量時造成誤差。無論因人為因素或自然因素所造成的遮蔽物，皆會阻擋漫射量造成全日空日射計所量測的輻射量減少，也會因這些遮蔽物直接阻擋或反射太陽光而增加或減少全日空日射計所量測到的輻射量。本研究以不移動此些遮蔽物為前提下，以計算出照片中各個遮蔽物的sky view factor，進而求得整體的環景遮蔭度，藉由環景遮蔭度能夠計算出因遮蔽物阻擋之漫射量；而反射還須知各個不同遮蔽物對太陽光所造成的反射情況，且因專門研究不同物體對太陽光之反射分布的實驗數據稀少，本實驗參考其他公布論文之實驗方法，自行設計出追日裝置，藉由此追日裝置進行太陽光對不同物體的反射分布實驗；並先使用高反射率之鋁板，鋁貼紙進行試驗，將結果和分光光譜儀所測得知結果進行比較，來驗證自行建立之實驗設備分析方法之確定性。最後由計算出之反射率，並藉由此反射率和從魚眼相片中算出的sky view factor 計算出因太陽光經遮蔽物反射而造成對全日空日射計所增加之輻射量。根據本研究之計算，澎湖馬公氣象站和台東氣象站之環景遮蔭度為8.4%和3%，針對馬公和台東兩個氣象站數據，選擇一個空曠且距離不遠之處架設一套標準件來進行量測標準件並和氣象站數據進行比對。經由漫射和反射之修正，在澎湖和台東皆可以有效地將誤差量縮小。台東2016年修正前平均誤差量為6.2%，經由本研究修正後，修正後平均誤差量為3.4%；2017年修正前平均誤差量為5.3%，修正後平均誤差量為2.7%。澎湖2015年修正前平均誤差量為12%，修正後平均誤差為10.5%；2016年修正前平均誤差為6%，修正後平均誤差為4.3%。且由本研究校正方法不會因季節不同而造成修正幅度不同，各個季節皆能穩定將修正前後誤差縮小。

Global radiation is typically divided into the following three areas: isotropic diffusion, beam radiation, and horizon brightening diffuse irradiation. A shelter next to the instrument is necessary when measuring global radiation (Figure 1).
However, shelters will cause shading effects and reflections. To correct the errors caused by such obstructions, it is necessary to determine the related reflectivity and shelter view factor.
Evaluation of shelter view factors is made by means of a fisheye-lens photograph together with the calculation method developed by Steyn (1980). There is little research on the surface reflectance of solar radiation, so this study refers to Marschner, et. al (2000) and Voss, et. al (2000) to design the facility (Figure 2) used to measure the reflectivity of an object.
Taitung Weather Station and Penghu Weather Station were chosen for the study. The shelter view factor for the pyranometer installed at Taitung Weather Station was estimated to be 8.4%, and that for the Penghu Weather Station was estimated to be 3%. Measurements of global solar radiation were conducted at a location near the weather stations but under conditions in which there is a zero shelter view factor.
It has been suggested that there is a need for correction if there are sheltering effects and error cause by reflection in the measurement of global solar radiation at weather stations, with the exception of locations that are not subject to surrounding obstacles in the sky dome. In this study, as much as a 4.05% correction was found at Taitung Weather Station, and as much as a 2.4% correction was found at Penghu Weather Station.

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