Yogya (KU) - Spatial modeling through satellite image processing, especially with hill-shade analysis, can be used as model to explore the potential income tax revenue of an individual. Based on this research, the use of satellite imagery in all villages in Klojen sub-district, Malang, East Java can estimate the potential of untapped individual income tax, which amounts to approximately four times of the total income recorded in the database.
"Income tax revenue could be increased up to three times from the current individual income tax revenues," said the Head of East Java Regional Office of Tax Directorate General III, Suharno, S.H, M.P.M, in open examination of doctoral promotion of Geography Study Program, Faculty of Geography Universitas Gadjah Mada (UGM), Saturday (8/5). According to Suharno, the total of the taxpayers is still relatively low, i.e. 3,380. This is due to the fact that not all taxpayers have been reported.
The satellite imagery analysis showed that there are 13,485 taxpayers. The analysis is based on the building height measurement through hill-shade analysis that reflects the actual height. "The results of each measured object are divided by the average building height of each object whilst to obtain estimated areas of each building, we calculate the number of floors and by the groundfloor area measured through identification of digital building maps processed from the image," he said.
He added that the result was used to obtain an indication of basic consumption expenses related to the use of the building in concern, such as for electricity, water and telephone. Based on spatial modeling, the estimated nominal is Rp812.63 billion and the potential personal income tax is Rp 69.44 billion, while the newly explored through the Tax Office is Rp15,66 billion or 22.55 per cent for income tax. "This situation shows the potential loss, Rp 53.78 billion, because the amount of income tax revenue is only 22.55 percent of potential revenue that can be obtained," explained the man born in Trenggalek on 21July, 1953.
On his dissertation, to the examiner team led by Prof. Dr. Suratman, M.Sc., Suharno emphasized that extensification and intensification programs are needed in tax offices based on the results of the spatial and economic modeling to obtain new individual income taxpayers. Through these programs, potential tax revenue is expected to be gained to raise the state tax revenue.