Bussolentheodolite
A Bussolentheodolite is a combination of a very precise compass and a theodolite . It enables measurements that are oriented to magnetic north . If the theodolite is provided with a total station , it is called a bus total station ; Measurements with these instruments are called bus tachymetry . Bussole total stations or theodolites allow an accuracy of the angle determination (magnetic azimuth) of 0.1 to 0.2 gon .
history
The Bussole theodolite was developed from the Bussole (French Boussole, from Italian “ bussola ”, “ box ”). A first stopover was the tripod compass, which was also called Bussole for short . Here the diopter of the Bussole has been replaced by a telescope with a height circle. In the case of a Bussolentheodolite or tachymeter, the compass socket sits on the tilting axis or between the telescope supports .
Areas of application
These devices were used when there are no surveying points for orientation, or when these cannot be seen due to a visual obstruction (for example in the forest). Bussolentacheometry was used as a method of archaeological site survey. Since the development of north-pointing gyroscopic theodolites , the use of bus tachymeters has continuously declined and has practically ceased with the availability of GPS . Only in places where GPS is not available and a gyro theodolite is too complex or too expensive, for example in cave exploration, bussole tachymeters are occasionally still used.
particularities
Due to the migration of the magnetic north pole , it is important to record the date and time of the measurement in the measurement log so that the direction can be calculated back when taking a new picture. Like any compass, the Bussole reacts to magnetic fields in the environment, which is why a Bussole tachymeter cannot be used near large amounts of metal (railroad tracks, electric fences) or underground if iron ore is present. The observer must also not use any metallic objects, such as B. carry pocket knives and key rings or metal pens for field bookkeeping with you.
literature
- Rudolf Glutz: Castle research with the theodolite. Archaeological prospecting on four Zug castle sites with the help of bus tachymetry. In: Tugium. 14, 1998, pp. 85-94.
- Gottfried Schulte, Wilhelm Löhr: Markscheidekunde for mountain schools and the practical use. 2nd improved edition. Springer-Verlag, Berlin 1941, p. 280.
