Establishment of an Improved Floor Area Ratio with High-Resolution Satellite Imagery

An Improved Floor Area Ratio (IFAR) which can describe the intensity of urban land development was proposed and estimated by means of remote sensing technique. The paper intent to conduct a quick and high-precision estimation of the index based on building shadows in high-resolution images. Firstly, the spectral characteristics of shadows were analyzed to establish a ratio band SR which would enhance shadow information. The object-oriented method was used to achieve the extraction of shaded areas. Secondly, GIS method was used to estimate the shadow length and building height. The inspection of the building height between the estimation result and the filed measured data showed an accuracy of 90%. Finally, the gross floor area of each building was calculated by multiplying the storeys with the basement area. Thiessen polygons were built by assuming the centroid of the basement area as a point. The IFAR of each building was the ratio of the gross floor area to the corresponding polygon. The IFAR have more abundant connotations by taking more information into consideration. The remote sensing tool can well extract the proposed index accurately on a very large scale.