GVR is a text based file format for transferring water table data originating from a software product called Autograph. The GVR format has changed over the years and there is no official documentation on the exact syntax of GVR. Therefore it is hardly possible to provide a GVR parser that will support all kinds of GVR files out there; however Redbex is able to parse a wide range of differently formatted GVR files. Below you find a description of the GVR file format as understood by Redbex.
Each GVR files contains data for one Redbex feature. The GVR import therefore will create or update one feature of type Ground water level for each GVR file. Details about what data is parsed and stored during can be found below.
Note: During import some of the values found in the GVR source files have to be translated to Redbex classification elements. It is therefore mandatory for this import that in the domain where the GVR files are imported used classifications are defined for classification types Aquifer type, Drill hole type and Standard comment.
The Import type specific settings are shown in table 1.
Setting |
Description |
Store source files |
If enabled the source files that were imported with each import session created from this import definition, will be stored on the Application Server and linked to the import session. This option gives you the possibility to store the original data files along with your import session. Default: false |
Coordinate system |
Mandatory. GVR files can contain spatial information (Easting, Northing) about the location of the ground water level. For correct interpretation of these values the user must select a coordinate system. The GVR import supports only projected coordinate systems. All newly created features will be set to this coordinate system. |
Value type |
Can be either Relative or Absolute. If Relative is chosen Redbex will convert the data in the source files to absolute values using the values of inclination and pipe top edge found in the source file. |
Create classification elements |
If set the import will try to create missing classification elements in used classifications for classification types Aquifer type, Drill hole type and Standard comment. Note that the user executing the import has to have the permission to modify classification elements of these classifications for this setting to have effect. |
Table 1: Import type specific settings
Physical structure of GVR files
GVR files are text files that can be in different encodings, Redbex supports UTF-8, UTF-16 or UTF-32, ASCII (7 bit), ANSI, for ANSI encoding Redbex will try to guess the code page. The file may use a BOM (Unicode byte order mark) to specify the byte order of the character encoding.
A line in the GVR file must be terminated by line feed character (U+000A, UTF-8: 0x0A, typical for Unix, Linux, Android, Mac OS X, BSD, and other operating systems), a carriage return (U+000D, UTF-8: 0x0D typical for Mac OS till Version 9 and other operating systems), or a carriage return immediately followed by a line feed (typical for Windows operating systems).
The file stem (= file name without extension) of a GVR file defines the ID (or name) of the ground water measurement point. The extension of the file is not relevant in Redbex but is usually GVR.
All numeric values in the GVR files use the point as decimal separator.
Logical structure of GVR files
GVR files consist of two parts: The mandatory header and the optional data part.
The first nine lines in the GVR file are interpreted by Redbex as the header lines. Each of these lines consists of one or more cells separated from each other by one or more spaces (SPACE, U+0020, UTF-8: 0x20). The exact meaning of each line and each cell in those lines is shown in Table 1.
All lines following the ninth nine header lines to the first line containing only the * character (ASTERISK, U+002A, UTF-8: 0x2A) are interpreted as comment lines and will not be used by Redbex in any way. The line with the single * character, terminates the header.
Line |
Cell |
Meaning |
1 |
1 |
Numerical value. Optional. Default is null. Defines Northing of the ground water measurement point. Northing and Easting and Elevation (see below) are used by Redbex to locate the measurement point. The values of Northing and Easting are interpreted in the Coordinate system the user has chosen in the import format settings. |
2 |
1 |
Numerical value. Optional. Default is null. Defines Easting of the ground water measurement point. |
3 |
1 |
Numerical value. Default is null. Terrain elevation at the ground water measurement point. |
4 |
Numerical value. Optional. Together Section and Distance (see below) provide an alternative way of defining the ground water measurement point location. Redbex does not use this information. |
|
5 |
1 |
Numerical value. Optional. Distance. Not used by Redbex (see above) |
6
|
1 |
Alphanumeric value. Mandatory. Type of the drilling (e.g. classified by casing. The type of drilling can be any alphanumeric string (without spaces). In Redbex this string ins translated into a classification element by case insensitive comparison of the string in the GVR file with the code of the classification elements of the used Drilling Type classification. |
2 |
Alphanumeric value. Mandatory. Defines if the GVR file contains exact points in time or just dates for each reading. A value of -1 or a Ja (case insensitive) indicates that the data part has time values. Any other alphanumeric value indicates that the data part has no time values. |
|
3 |
Alphanumeric value. Optional. Not used by Redbex |
|
7 7 |
1 |
Numeric value. Mandatory. Elevation of top edge of pipe (= Reference elevation if data is interpreted as depth values). Use -999 if top edge is unknown. Note that in that case depth values cannot be converted to absolute values. Values less than -100 or greater than 10000 are invalid. |
2 |
Numeric value. Optional (Default value 0). Bearing of the drilling given in compass degrees. If the drilling is not a perpendicular drilling this cell gives the direction of the drilling. For a perpendicular drilling the value of this cell shall be 0. Values < 0 or greater 360 will be normalized to a range in [0, 360] |
|
8 |
1 |
Numeric value. Mandatory. Final depth of the drilling expressed as elevation. Use -999 if final depth elevation is unknown Values less than -100 or greater than 10000 are invalid. |
2 |
Numeric value. Optional. Default is 90 Inclination of the drilling given in degrees. 90 is perpendicular down, -90 is perpendicular up. Values less than -90 or greater than 90 are invalid. |
|
9 |
1 |
Numeric value. Mandatory. Default is null Filter length must be greater than 0. Use -999 if filter length is not known or not applicable. |
2 |
Numeric value. Mandatory. Average value of measurements. Not used by Redbex. |
|
3 |
Alphanumeric value. Optional. Default is empty Type of aquifer (classified by its geological characteristics). The type of aquifer can be any alphanumeric string (without spaces). In Redbex this string ins translated into a classification element by case insensitive comparison o f the string in the GVR file with the code of the classification elements of the used Aquifer Type classification. |
Table 2: Description of header lines and cells in the GVR file format
All lines after the line with a single * terminating the header are interpreted as data lines. Empty lines are ignored. The first line with a single * after the start of the data part is terminating the data block and the GVR file. Any data after that line is ignored. If no such line is found for the data part Redbex will read all data till the end of the file.
The contents of a data line is again organized in cells. The first 5 cells are mandatory (have to be present in any GVR file) and are separated by one or more spaces. Table 2 describes the meaing of these 5 cells.
Cell No |
Description |
1 |
Numeric value. Mandatory. Year when measurement was taken |
2 |
Numeric value. Mandatory. Month when measurement was taken |
3 |
Numeric value. Mandatory. Day when measurement was taken |
4 |
Numeric value. Mandatory. Measured value. This value is interpreted either as depth or as absolute elevation. Depending on the import format settings. Use -999 to express null. |
5 |
Alphanumeric value. Mandatory. Correctness of measurement. J is interpreted as correct all other values are interpreted as incorrect. In Redbex an incorrect measurement is stored as erroneous observation. |
Table 3: Description of the first 5 cells cells in a data GVR line
If the header of the GVR file specifies that the file contains time the last 8 characters of the line are interpreted as time (format hh:mm:ss).
The data between the 5th cell and the time (or the end of line if no time is given) is interpreted as standard command and free comment. The standard comment is a comment that is interpreted by Redbex by matching that string against the Standard Comment Classification. If a (non-empty) free comment is found that comment will be added as observation comment in the observation's associated data. The standard comment is separated from the free comment by a single space. Maximum length of the standard comment is 25 characters.
Examples
Example 1: GVR file with a single data line, no comments, and no time
Example 2: GVR file using exact points in time.
Example 3: GVR file with no time, but including comments.
Example 4: GVR file without a data part
