Retrieval of Aerosol Optical Depth（AOD）over land through satellite remote sensing is difficult. Traditional methods to retrieve aerosol over land involve the use of the Dense Dark Vegetation（DDV） algorithm. However

this algorithm requires the support of an infrared band and dark pixels. Compared with DDV

the structure function method can be utilized to retrieve AOD over bright areas with high surface reflectance. However

the precision of retrieving AOD through the structure function method can be significantly influenced by pixel distance. Not all pixels can be retrieved with high precision; this condition results in a large amount of unnecessary computations. As a result

determining the pixel distance settings and the pixels with a small retrieval error is important in improving the retrieval precision and efficiency of the structure function method.To acquire the best pixel distance settings

we calculated the structure function values with different pixel distances and obtained the final structure function value of the target pixel through single-pixel distance

average

slopeheight

and average linear area methods to retrieve AOD at 550 nm over Kiaochow Bay. The first band of nine-scene MODIS L1 B data with resolutions of 250 m and 500 m was used.Surface reflectance was the minimum value of the first band of MOD09Q1 in 2012. By validating the AOD data measured by CE318 and by analyzing the retrieval result and spatial distribution of AOD

we obtained the pixel distance settings with high precision and minimal effects of resolution. The experiment indicated that the average linear area method has a small retrieval error whether the resolution is 250 m or 500 m. According to statistics and by analyzing the structure function value of the surface reflectance of pixels with an acceptable error（the absolute value of the absolute error is 0.1 for measured AOD less than 0.6 and 0.2 for measured AOD greater than 0.6）

we found that the ratio of pixels with are solution of 500 m is obviously larger than that with 250 m resolution. Pixels with a surface reflectance structure function value larger than 0.02 have a good result and areaways distributed over areas with a sudden change in geographical elements

such as piedmonts

mountain streams

coasts

rivers

and rural–urban continua. In this study

we utilized different methods and historical surface reflectance data with two resolutions to calculate the final structure function value. The retrieval precision and distribution of AOD were analyzed to acquire the best pixel distance settings

and its features were identified through the statistics of the structure function values with high retrieval precision. The average linear area method is stable

and its result has an insignificant relationship with data resolution. The retrieved AOD with high precision is concentrated on pixels with a surface reflectance structure function value larger than 0.02. The efficiency of this method increases when the measured AOD is greater than0.5.