Inventors:
Chan Park - Oakland CA, US
International Classification:
G01C015/06, G01B011/26
Abstract:
A measuring system includes an optical site reference, such as a reference line within a scope used in surveying, and a calibrated reference scale which provides measurements by optical comparison to the optical site reference. The calibrated reference scale includes centimeter sections which in turn include upper and lower stepped sections. The upper and lower stepped sections are symmetrical with respect to one another such that the upper and lower stepped sections can be easily distinguished from one another from significant distance. Each of the steps of each stepped section indicates a specific, corresponding offset within the stepped section. The symmetry of the upper and lower stepped sections is in the relative positions of the long and short reference members. The calibrated reference scale includes a number of digit reference sections which are spaced a predetermined distance from a reference point along the calibrated reference scale and include an alphanumeric representation of that predetermined distance. The alphanumeric representation has a predetermined height such that the alphanumeric representation itself provides a reference for offsets from a base of the alphanumeric representation. In particular, those alphanumeric representations which have horizontal components place those horizontal components so as to provide relatively evenly spaced references which the digit reference section.