Theodolites are a common instrument in the testing, alignment, and building of various systems ranging from a single optical component to an entire instrument. They provide a precise way to measure horizontal and vertical angles. They can be used to align multiple objects in a desired way at specific angles. They can also be used to reference a specific location or orientation of an object that has moved. Some systems may require a small margin of error in position of components. A theodolite can assist with accurately measuring and/or minimizing that error.
Previously, when aligning a system with a theodolite, it required the user to use their unaided eye with the theodolite eyepiece. When viewing the alignment through the eyepiece, the user could induce human error by how well they could see the alignment indicators. Other attempts have used a bare CCD (charge coupled device) array attached to the theodolite, but this technique limited the ability to achieve proper focus of the theodolite because it did not properly simulate the human eye, and therefore introduced error.
This technology minimizes time required to align a system with a Leica WildT3000 Theodolite or multiple theodolites. The secondary objective was to allow a single individual to align a single coupled system to multiple theodolites, simultaneously, in real time. This technology mounts a CCD camera with a lens at the theodolite eyepiece. This simulates the human eye and creates an improved way to align a system with the theodolite by increasing accuracy and adding the ability to record alignment quantitatively.
The technology is an adapter for a CCD camera with lens to attach to a Leica Wild T3000 Theodolite eyepiece that enables viewing on a connected monitor, and thus can be utilized with multiple theodolites simultaneously. This technology removes a substantial part of human error by relying on the CCD camera and monitors. It also allows image recording of the alignment, and therefore provides a quantitative means to measure such error.
This method allows a fast and accurate method of alignment and minimizes the need for multiple individuals to perform alignment of multiple theodolites. It also eliminates the need to look through the eyepiece of the theodolite, thus eliminating the chance of eye injury when dealing with high-intensity light sources. This method allows the ability to place the theodolite in constrained locations that someone using the traditional human eye technique could not do.
This work was done by Shane Wake and V. Stanley Scott, III of Goddard Space Flight Center. GSC-16175-1