The calculated distance (air line) between Pyŏksŏng-ŭp and Sunch’ŏn is approximately 98 miles respectively 157 kilometers.
By car or train, the actual journey to Sunch’ŏn is certainly longer, as only the direct route (as the crow flies) between Pyŏksŏng-ŭp and Sunch’ŏn has been calculated here.
Air line (approximately)
157 kilometers
85 nautical miles