A method for determining the position data of a geodetic surveying instrument by • recording an image of the environment (1, 9, 11, 12) of at least one contiguous region of the environment of the surveying instrument position to be determined, • providing a multiplicity of stored position-referenced volumes of data (4, 13, 14, 15, 22c) from position-referenced data records, • extracting a reference volume of data (22b, 35) consisting of read or derived data of the one image of the environment (1, 9, 11, 12) by means of image processing, wherein each position-referenced volume of data (4, 13, 14, 15, 22c) and the reference volume of data (22b, 35) have data of corresponding type (D1a, D1b, D2a-D2d, D3a-D3e, D4a-D4e, 40), • collating the reference volume of data (22b, 35) with the provided position-referenced volumes of data (4, 13, 14, 15, 22c) with identification of matches between reference volume of data (22b, 35) and a respective individual position-referenced volume of data (4, 13, 14, 15, 22c), • selecting that position-referenced volume of data (4, 13, 14, 15, 22c) that matches, within certain tolerance limits, the reference volume of data (22b, 35), • ascertaining the position data of the surveying instrument position on the basis of position reference of the selected position-referenced volume of data (4, 13, 14, 15, 22c), in particular wherein the ascertaining of the surveying instrument position is adoption of the absolute position data of a real or computed recording location associated with the selected position-referenced volume of data (4, 13, 14, 15, 22c), characterized in that an ascertainment of an, at least coarse, surveying instrument orientation is effected on the basis of referenced orientation data of the selected position-referenced volume of data. • recording an image of the environment (1, 9, 11, 12) of at least one contiguous region of the environment of the surveying instrument position to be determined, • providing a multiplicity of stored position-referenced volumes of data (4, 13, 14, 15, 22c) from position-referenced data records, • extracting a reference volume of data (22b, 35) consisting of read or derived data of the one image of the environment (1, 9, 11, 12) by means of image processing, wherein each position-referenced volume of data (4, 13, 14, 15, 22c) and the reference volume of data (22b, 35) have data of corresponding type (D1a, D1b, D2a-D2d, D3a-D3e, D4a-D4e, 40), • collating the reference volume of data (22b, 35) with the provided position-referenced volumes of data (4, 13, 14, 15, 22c) with identification of matches between reference volume of data (22b, 35) and a respective individual position-referenced volume of data (4, 13, 14, 15, 22c), • selecting that position-referenced volume of data (4, 13, 14, 15, 22c) that matches, within certain tolerance limits, the reference volume of data (22b, 35), • ascertaining the position data of the surveying instrument position on the basis of position reference of the selected position-referenced volume of data (4, 13, 14, 15, 22c), in particular wherein the ascertaining of the surveying instrument position is adoption of the absolute position data of a real or computed recording location associated with the selected position-referenced volume of data (4, 13, 14, 15, 22c),