Importing Data

ASCII import

The ASCII import reads data from an ASCII file into the Geocap project. ASCII import can be used for many types text data files, e.g. whether the data columns have fixed or variable width, and also whether the coordinates are in X Y or Lat Lon. When data is read into the project, it can be organized in a number of different ways. It is for example possible to tell Geocap to split the data into different dataset whenever a value in a specific file column changes. There are also options for creating project folders whenever a column value changes.

The ASCII import has the ability to read more fields than X Y Z (text or numbers). In many cases the user will notice that when importing data in Geocap, the ASCII import will appear ready and pre-set to read the data in question. For instance, when reading UKOOA data, the ASCII import will appear properly adjusted to the UKOOA format - saving the user from having to set this from scratch.

Column formats

A number of different data types can be represented as an ASCII file on column format. The word column indicates that the data is stored in columns inside the file. Let us clarify what we mean by columns with two examples. Example 1 uses variable columns while Example 2 uses fixed columns.

A file on variable column ASCII format contains separators that separate one column from the next. A separator is usually some form whitespace character(s), for example TAB.

  # Header: Variable columns sample file
  101491.0       6760050.       2155.130
  100162.0       6760540.       2217.300
  98843.0        6761020.       2194.980
  97514.0        6761500.       2229.990
  96195.0        6761980.       2170.360
  :              :              :
  :              :              :

A file on fixed column ASCII format uses column numbers to separate one column from the next. The sample file in Example 2 has Line name in columns 1 through 14.

  # Header: Fixed columns sample file
  LINE-01        1640430.70S 431309.10E 996859.12854609.4
  LINE-01        5640432.20S 431254.40E 996654.42854595.4
  LINE-01        9640433.80S 431239.80E 996450.62854578.1
  LINE-01       10640434.20S 431236.20E 996400.32854573.7
  LINE-01       14640435.70S 431222.00E 996202.42854558.5
  :              :              :
  :              :              :

In the example above, the columns used for X and Y are, 37-46, and 47-55 respectively

ASCII menu

ASCII import menu

1. Browse in the dataset. Geocap lets you browse in several datasets, enabling you to import them in one go, presuming they have the same formatting.
2. Adjust the header spinbox so that header information is displayed in the header preview and the data is displayed in the data preview sections. Header preview will not be apart of the imported dataset.
3. Set whether or not the file data columns are separated by white space or some other character. If your column separator is not on the list select Myseperator and type in the wished string. If your data is of type fixed width, tick the fixed columns box, and set the width of your specified columns.
4. Geocap can read your data in X and Y's or in latitudes and longitudes. If your data is in latitudes and longitudes, you can choose between a variety of variants, e.g. decimal (deg) or DDMMSSSS.
5. The Scalars field S can be used to read an "extra" data attribute. For instance when reading velocity data, Geocap recommends the user to read the velocities as the scalar field S. Geocap will expect the user to read X Y Z S where Z is the time value, and S is the velocity. Another example of the use of scalar is when reading interpretation data where the scalar can hold the amplitude.
6. If your data has more fields than X, Y, Z and S, it is possible to add new fields. Add the extra attributes/fields as required. For each new file column defined, one needs to give the column a name, and also to specify whether the data input for this column is numeric or text.
7. It is important that the user specifies which file column contains what data. In the example above, the following columns are defined: X-1, 2-Y, 3-Z, 4-SP, and 8-LineName(cell separator).
8. Specify if your data is line or points. The main difference is that line data will be displayed as lines, and points data as points. In the example given above, interpretation data is read as lines to produce better display options (e.g. the interpretation along the 2D lines displayed as lines and not points).
9. For both line and point data, it is possible to separate one dataset into separate cells. Sometimes this is necessary for display purposes, e.g. a coastline where each island along the coast has to be a separate cell (or else it would be impossible to display the data without connecting lines going from one island to the next). Another example of a dataset where cell separation is necessary, is velocity pairs, where all pairs from one analysis (SP) belong to one cell. In the example above, the cell separator is set to value change in column number 8 congaing the Seismic 2D line names, meaning that when displaying these data they will be displayed as lines (each cell one line).
10. Geocap can also create many dataset from reading one single file. For instance, if you want to separate the interpretation data in the example dataset above into separate datasets, one for each seismic 2D line, then you would set Seperate datasets to Value change and the Data separator column number to 8 which contains the Line Name.
11. It is also possible for Geocap to generate project folders based on input data. This option is always used in combination with the Separate dataset option. One example could be to import seismic velocities for many seismic vintages, where the year of acquisition was specified in one column. It would then be possible to set folder creation based on Year, Dataset creation based on Seismic survey, and cell separation based on SP change.
12. Set the correct Schema for your dataset type. Seismic velocities would for instance be read under the schema Stacking Velocities

Fixed column format

Often, the columns in data files are fixed, and the user needs to set the columns so that they read the correct data.

Example of fixed column import

In the example above the Lat Deg value is "inside" a number, and we want to fetch this out.

1. Tick the Fixed columns option.
2. Use the combo box to select the column to set. This has to be done for each column to read. Notice that the characters of one sample line are displayed and the that selected columns set characters are displayed in red color.
3. Use the arrows to move set character positions to read to the left or right
4. Use the small up and down arrows to set the total number of characters to read for the selected column

ASCII import is used when:

• Importing Points and Lines
• Importing Interpretation
• Importing Velocities
• Importing Wells

Generic import

Generic import menu

The Generic import is used to import a number of different formats, such as images, grids, VTK etc. For a complete list of import formats look in the appendix: Generic Import Formats

When browsing in a file, the Generic import should recognize the file format, if the Format option has been set to Automatic. However, sometimes you will need to set the file format in the Format option. The Generic import also lets you select a Schema and an import area of your data set. You can define this import area under the Area of Interest tab.

Generic import is used when:

• Importing Grids
• Importing Images
• Importing Shapefiles