https://blog.gongquiz.com/2022/01/03/%ec%b5%9c%ec%8b%a0-%ed%8f%ac%ec%bc%93%eb%aa%ac%ea%b3%a0-gps%ec%a1%b0%ec%9e%91-%ed%85%94%eb%a0%88%ed%8f%ac%ed%8a%b8-100%ec%97%91%ec%84%a4%eb%9f%b0%ed%8a%b8-%eb%93%b1%eb%93%b1-%e2%85%b2/