Distance measurement

Distance measurement is used to check and document distances by direct or indirect comparison with a unit of length. It is also called distance or length measurement. From atomic physics to astrophysics, distance measurements of various types take place in almost all areas of scientific research and technical production. The range of possible measurement lengths spans a whole 44 decimal orders of magnitude, and thus truly takes on both microscopic and macroscopic dimensions. Thus, there is also an enormous variety of different methods for all the applications of distance measurement. Combined with direction measurement, distance measurement can be used to determine the location of points in a two- or three-dimensional coordinate system; an important capability for metrology. While optical interferometry measures a breadth of distances from attometers to full meters, the confocal microscope technique is also recommended in the nanometer to millimeter range, while direct measurements from the micrometer to the meter range provide good results. The triangulation method can be used to reliably measure distances from the micro to the zettameter range. Time-of-flight measurement as well as radio interferometry both start in the millimeter range, with time-of-flight measurement maxed out at the tera range, while radio interferometry still covers the full petameter spectrum. With the parallax and the redshift, size ranges of the space survey can be reached.