經緯儀水平角「複測角法」討論

「複測角法」是一項能夠具體提升角度解析度的作業方法。在20 世紀初期起，藉由「複測經緯儀」該法獲得實踐。該種類經緯儀，具有上、下盤構造，適於「複測角法」之施測。爾後，隨同儀器製造科技的提升，「方向經緯儀」幾乎全面替代「複測經緯儀」，「複測角法」亦隨之而成為過時的作業方式，經常於基礎測量教學中移除。而在測量儀器科技再次進化之發展下，電子經緯儀與全測站儀，業已全面替代機械式與光學式讀數之儀器。而在電子化之發展結果裡，「複測角法」已無需具有上、下盤構造之儀器實踐，使用簡便的「凍結」按鈕，便可進行往昔的「下盤動作」，又再度提供「複測角法」作業之環境。檢視「複測角法」之基本觀念，十分切合測量工作的基本精神：「使用適當之作業方式，提升測量成果」。雖然，「複測角法」之實用性在學界受到許多學者質疑，但是其為一種可行之作業方式，於需要時實施，蓋無疑義。本文謹就「複測角法」之基本精神、儀器環境，予以探討，並就其作業效益具體分析。但是就基礎測量教學上是否應包含此一方法，不同觀點會有不同結論。 The repetition method is an observation scheme which could practically improve the resolution ofhorizontal angle measurement. This method was realized with “repeating theodolite”. This typeinstrument is structured with upper and lower plates with two vertical axes which could rotateindependently. With the advent of instrument technology, “direction theodolite” almost completelyreplaced “repeating theodolite”, and also the “repetition method”. Once again, with the advent ofinstrument technology, electronic theodolite and total stations have replaced instruments with mechanicalor optical angle reading devices. With the electronic devices, a simple “Hold” button could freeze thehorizontal angle reading and facilitate “repetition method”. “Repetition method” is based on the fundamental surveying concept. That is, with properoperation schemes, observation of better quality is obtained. Although the practical value of“repetition method” may be questionable in today’s surveying environment, this method istheoretically sound and practically usable. This note describes the fundamentals of “repetitionmethod”, its operation, and also the expected improvement. However, regarding whether thismethod should be included in the lectures of fundamental surveying course, the conclusionwould be highly dependent on the viewpoints.

The repetition method is an observation scheme which could practically improve the resolution ofhorizontal angle measurement. This method was realized with “repeating theodolite”. This typeinstrument is structured with upper and lower plates with two vertical axes which could rotateindependently. With the advent of instrument technology, “direction theodolite” almost completelyreplaced “repeating theodolite”, and also the “repetition method”. Once again, with the advent ofinstrument technology, electronic theodolite and total stations have replaced instruments with mechanicalor optical angle reading devices. With the electronic devices, a simple “Hold” button could freeze thehorizontal angle reading and facilitate “repetition method”. “Repetition method” is based on the fundamental surveying concept. That is, with properoperation schemes, observation of better quality is obtained. Although the practical value of“repetition method” may be questionable in today’s surveying environment, this method istheoretically sound and practically usable. This note describes the fundamentals of “repetitionmethod”, its operation, and also the expected improvement. However, regarding whether thismethod should be included in the lectures of fundamental surveying course, the conclusionwould be highly dependent on the viewpoints.