2台の光波測距儀による同時比較測距

抄録

Side-by-side distance measurements by two Geodimeters were made in order to investigate the origin of fluctuations in measured lengths with a period from a few tens of minutes to one hour. The light paths and distances for the instruments were set to be close to each other, and the measurement was carried out within a few hours before and after sunset for four consecutive days. A weak correlation was found in slow fluctuations with a period of one to four hours in the two lengths observed with the two Geodimeters; the is considered to be due to the change of light velocity along the path. On the other hand, there can hardly be seen any certain relationship in the fluctuations with short periods (10-20 minutes), so that they are presumably caused by the instrumental error. It is also suggested that an accuracy higher than ±1.0X10^-6 will be obtainable in the distance measure ments with Geodimeter 6BL by repeating measurements many times within a few hours around sunset.