proj4.defs("EPSG:7831","+proj=tmerc +lat_0=0.0833333333333333 +lon_0=41.5 +k=1 +x_0=7300000 +y_0=0 +ellps=krass +towgs84=24,-123,-94,-0.02,0.25,0.13,1.1 +units=m +no_defs +type=crs");