QC Tools in Airborne Geophysics at Rybno Geo Data

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Grid data at Rybno Geo Data are stored using the quite common format NetCDF, especially used at institutions for climate research. Therefore a number of viewers are available. Another option there is to produce map products in postscript or PDF, eventually displaying First Vertical Derivative or higher derivatives, also with a shadow map added. This can be done very efficiently using the Generic Mapping Tools. It can then be printed on some plotter or just viewed online on a computer screen.

Line data and other ancillary information like some processing coefficients or line lists are stored in so-called cubes, very compact databases which maybe compressed. The compression level is a property of the initialized data set and therefore, the compression and the de-compression is done in the read or write stream respectively leading to reduced i/o volume and therefore fast r/w  operations. Big data sets are stored in chunks which are directly accessible through B-trees which allows for very quick recovery of line segments as well as storing partial data sets.

One central data structure is the data channel as shown on the screen shot under "Line Data". Each channel has a version number under which the data set is finally stored. In most cases there is only one version '0' which is the link to the data set. Additionally there is one link 'C' (like current) which points to the version which should be used by default. If there are more versions, for example some edited version of ground magnetometer data, the link 'C' can be set to the version which should be used for further processing.

Because this data format is quite a unique development, it was necessary to develope our own tool for viewing and inspection. This was done using the platform independent graphical user interface (GUI) framework of Qt. A screen shot is shown under "Line Data".