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3.1 Lineage

The lineage portion of a quality report must include a description of the source material from which the data were derived and the methods of derivation, including all transformations involved in producing the final digital files. The description must include the dates of the source material and the dates of ancillary information used for update. The date assigned to a source must reflect the date that the information corresponds to the ground; however, if this date is not known, then a date of publication may be used, if declared as such.

Any data base created by merging information obtained from distinct sources must be described in sufficient detail to identify the actual source for each element in the file. In these cases, either a lineage code on each element or a quality overlay (source data index, etc.) must be required.

The lineage portion must also include reference to the specific control information used. Control from the National Geodetic Reference System must be identified according to identifiers in that system, while other points used for control must be described with sufficient detail to allow recovery.

The lineage portion must describe the mathematical transformations of coordinates used in each step from the source material to the final product. The locations of any registration points for coordinate transformations must be given. The methods used to make coordinate transformations must be documented. To fulfill this standard, it is acceptable to make reference to separate documentation for the coordinate transformation algorithm used, but the specific parameters applied must be described for the particular case. Documentation of a transformation algorithm must include the nature of computational steps taken to avoid loss of digits through roundoff and must include a set of sample computations including numerical values of coefficients to confirm equivalence of transformations. The documentation of a transformation algorithm must be available on request by a user obtaining digital data even if that user is not licensed to use the particular software.