File Types
Surfer uses four basic file types: data, grid, base map, and Surfer .SRF files.
Data Files
Various types of data files are used to produce grid files, point cloud maps, and drillhole maps or to post data points on a map. These files are generally referred to as XYZ data files or data files throughout the help. Data can be read from various file types, including XLSX, CSV, and TXT. Most data files contain numeric XY location coordinates and optional Z values. The Z values contain the variable to be modeled, such as elevation, concentration, rainfall, or similar types of values.
XYZ data files contain raw data that Surfer interprets to produce a grid file. To create a grid file, you must start with an XYZ data file. XYZ data files are organized in column and row format. Surfer requires the X, Y, and Z data to be in three separate columns.
Grid Files
Grid files, also known as raster files, produce several different types of grid-based maps, are used to perform grid calculations, and to carry out grid operations. Grid files are a regularly spaced rectangular array of Z values in columns and rows. Grid files can be created in Surfer using the Home | Grid Data | Grid Data command or can be imported from a wide variety of sources such as WCS servers or other applications. Supported grid file formats include GRD, ASC, and ADF.
Base Map Files
Base map files contain XY location data such as aerial photography, state boundaries, rivers, or point locations. Base map files can be used to create layers overlaid on other map types, or to specify the limits for assigning NoData values, faults, breaklines, or slice calculations. Base map files can be created from a wide variety of vector and image formats. Base map files may be referred to as vector data files, raster data files, and images or image files in the help, depending on the type of data in the base map file. Supported base map file formats include SHP, DXF, JPG.
Surfer Files
Surfer .SRF files preserve all the objects and object settings contained in a plot window. These files are called Surfer .SRF files throughout the documentation. Surfer can open .SRF files from previous versions as far back as Surfer 7. Surfer can save files to previous .SRF formats for sharing with other users. For example, the Surfer 15 Document .SRF file type can be opened in Surfer 15, but does not contain features that are in later Surfer versions. Beginning with version 16, the Surfer Plot (*.srf) file type is backwards compatible with all Surfer versions 16 and newer.