| Taking the Yangtze River Delta as the research area, the applicability of spatial interpolation method for aerosol optical depth interpolate was discussed from sampling density, measured data and spatial distribution. The results showed that with the decrease of sampling density, the goodness of fit R2 between AOD spatial interpolation results and original image increased as power function, the inflection point was around 5%. Natural neighborhood interpolation was the best method. After interpolation, the proportion of days with valid AOD data from satellite increased to about 70%, the correlation coefficient R＞0.8, and the annual mean value increased from 0.48 to 0.66, showing a gradual decreasing trend from northwest to southeast. The standard deviation increased from 0.27 to 0.38, showing a gradual decreasing trend from north to south. The proportion of days with valid data showed an increasing trend with the precipitation decreasing from south to north. The proportion of days with valid data on water surface and mountain area was low. When the sampling density was 5%, the correlation coefficients between interpolation results and the spatial autocorrelation of original image, standard deviation and mean value were 0.74, 0.73 and 0.69, respectively. |
