What is a typical range for tropospheric duct propagation of microwave signals?
10 miles to 50 miles
100 miles to 300 miles✓Правильный ответ
1,200 miles
2,500 miles
Объяснение
Ducts are local weather structures of limited extent, so trapped microwave signals typically travel a few hundred miles — far beyond line of sight but well short of intercontinental distances. Ten to fifty miles is roughly ordinary line of sight and requires no duct at all.