2 XML input data format for gama-local

The input data format for a local geodetic network adjustment (program gama-local) is defined in accordance with the definition of Extended Markup Language (XML) for description of structured data. The XML definition can be found at

Input data (points, observations and other related information) are described using XML start-end pair tags <xxx> and </xxx> and empty-element tags <xxx/>. The syntax of XML input format is defined in the Document Type Definition (DTD) at

and can formally be validated independently on the program gama-local.

For parsing the XML input data, gama-local uses the XML parser Expat copyrighted by James Clark which is described at

Expat is subject to the Mozilla Public License (MPL), or may alternatively be used under the GNU General Public License (GPL) instead.

In the gama-local XML input, distances are given in meters, angular values in centigrades and their standard deviations (rms errors) in millimeters or centigrade seconds, respectively. Alternatively angular values in gama-local XML input can be given in degrees and seconds (see Angular units). At the end of this chapter an example of the gama-local XML input data object is given.

• Angular units: Angular units
• Prologue: XML declaration
• Network definition: Tags <gama-local> and <network>
• Network description: Tag <description>
• Network parameters: Tag <parameters />
• Points and observations: Tag <points-observations>
• Points: Tag <point />
• Set of observations: Tag <obs>
• Directions: Tag <direction />
• Horizontal distances: Tag <distance />
• Angles: Tag <angle />
• Slope distances: Tag <s-distance />
• Zenith angles: Tag <z-angle />
• Height differences: Tag <height-differences>
• Control coordinates: Tag <coordinates>
• Coordinate differences: Tag <vectors>
• Example: A complete example of a network