| 摘要 |
PROBLEM TO BE SOLVED: To provide a calculation method and its recording medium that can estimate attenuation amount by buildings, depending on the utilizing state of lands and its number of households, even when the height data of the buildings are not available, to calculate the attenuation amount in a city. SOLUTION: First, a scale of a city in the direction of a transmission point is obtained from land utilization data from a receiving point to obtain an attenuation by buildings (S1), then the attenuation is compared with a building attenuation obtained from data of number of households, the attenuation, which is the larger, is selected for a maximum attenuation of the building (S2). When a frequency to be checked is a VHF, the maximum building attenuation is halved (S3), a fault distance on a path is obtained, depending on an incident angle onto the receiving point (S4), the maximum building attenuation is corrected by the land use classification and the land form in the fault distance on the radio wave path (S5), and is also corrected by the incident angle (S6), Fresnel loss is calculated (S7) and then finally the city attenuation is calculated (S8). |
