百度地图返回的这个geo的前半段数字代表什么

{"content":{"geo":"4|13375480.97,3519658.96;13375695.97,3519839.46|1-13375480.97,3519789.96,13375499.34,3519695.34,13375490.93,3519685.33,13375498.97,3519658.96,13375624.47,3519687.96,13375636.97,3519694.96,13375629.97,3519744.85,13375636.98,3519764.86,13375695.97,3519773.96,13375683.47,3519839.46,13375635.97,3519830.96,13375583.44,3519823.36,13375575.42,3519838.37,13375480.97,3519789.96;","uid":"4ea3f2f1522b0dabaecb66d0"}

全是纸图坐标,比如13375480.97,3519658.96就是一个坐标点