Viking 1 Lander on the surface of mars: Revised location

Late in 1977, the periapsis altitude of the Viking Orbiters was lowered from 1500 to 300 km. The higher resolution of pictures taken at the lower altitude (8 m/pixel) permitted a more accurate determination of the location of the Viking 1 Lander by correlating topographic features seen in the new pictures with the same features in lander pictures. The position of the lander on Viking Orbiter picture 452B11 (NGF Rectilinear) is line 293, sample 1099. This location of the Viking 1 Lander has been used in a revision of the control net of Mars (M.E. Davies, F.Y. Katayama, and J.A. Roth, R2309 NASA, The Rand Corp., Feb. 1978). The new areographic coordinates of the lander are lat 22.483° N and long 47.968° W. The new location is estimated to be accurate to within 50 m.