Surfer supports exporting to many different file formats. When exporting data from Surfer for use either in another software package (either another Golden Software package or a third-party application), for inserting into a publication, or for any other purpose, the multitude of supported file formats can be confusing. It may not always be clear when you should be using the Golden Software file types (e.g. BLN, GSB, GSI, etc) or another file format (e.g. DXF, SHP, MIF), or when you need another file format altogether.
There are three main types of files you can export or save from Surfer: grid files, data files, and base map files. The base map file formats can be further subdivided into three types, raster image, vector and metafile formats. Which format you choose to export depends on what you are exporting, and what you want to do with the exported data.
| 1. Grid Files (e.g. ADF, ASC, DEM, GRD) |
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| 2. Data Files (e.g., CSV, DAT, TXT, XLSX) |
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| 3. Base Map Files | |
| 3a. Raster Image (e.g. BMP, JPG, GeoTIFF, TIF) |
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| 3b. Vector (e.g. E00, DXF, KML, MIF, SHP) |
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| 3c. Metafile (e.g. EMF, WMF) |
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Grid and data file formats are fairly self-explanatory with little variation in the content in these files. This article will not focus on these formats, but give some brief information:
- Grid files contain XY extents in map units, grid spacing, Z values at grid nodes (or grid cell centers, depending on the grid file format), and null values. There is not much variation in the information saved to these types of files. You could save a grid from Surfer to create contours, watersheds, or other map types in Surfer or other applications, or perform other grid calculations such as math or volume operations. The X, Y and Z information is the same in all grid formats, so the format you choose depends on the supported file formats of the program with which the grid will be used. For example, if you work primarily in Surfer, save grids in the default Surfer grid file format. If you want to bring the grids into ArcMap for display, save the grids in one of the supported ESRI grid formats (e.g. ADF, ASC or FLT).
- Data files contain raw data. Data files can be Excel spreadsheets, TXT or other ASCII data files. They can contain XY information along with Z values, labels, or other data. Again, there is not much variation as all of the data files contain the same basic information. You can save a data file from the Surfer worksheet in many different formats, including CSV, DAT or XLSX. The data saved will be the same in all formats. The only formats that may have a difference are the Excel formats if you have many thousands of rows of data. This is because the Excel formats are limited to a certain number of rows and columns:
- XLS file format is limited to a 65536 rows and 256 columns
- XLSX is limited to 1,048,576 rows and 16,384 columns
This article will focus primarily on the variations in the various base map file formats. As mentioned previously, the base map file formats can be further subdivided into three types: raster image files, vector files, and metafiles.
Raster images are images of exactly what you see on the screen. This type of file is a good option for sending a picture of the map to a colleague, inserting the image into a report or presentation, uploading the image to a website, or sending the image to a publication for print. This is also a good choice if you need a georeferenced image to overlay with other map types either in Surfer or other applications. Normally individual elements are not editable in raster image file formats. So, line styles, line widths and text properties are not editable. Some options, such as color, are editable using image processing software.
Similar to grid and data files, there is little variation in the actual content of these files. A picture of what is in your Surfer project file is exported. The main differences between formats are some of the format-specific options. Which format you choose depends on if you need compression, background transparency, or what format you are required to provide (if you are going to use it in another application or for publication).
All the image export formats support options for setting the pixel size, resolution (e.g. dpi), document size, and color format for the exported image. In addition, all image formats have the option to include spatial reference information, such as real world XY coordinates and coordinate system (e.g. projection/datum) information.
The spatial reference information can be saved in a number of formats, including an internal only format (e.g. GeoTIFF), or in external files, such as:
- Blue Marble .RSF file
- ESRI World file (.xxW)
- ESRI .PRJ file
- Golden Software Reference (.GSR and .GSR2) files
Note that the Blue Marble RSF and ESRI World files only contain XY coordinate information. They do not contain any coordinate system information. Likewise, the ESRI PRJ files only contain coordinate system information and no XY coordinate referencing. Golden Software Reference files contain both real world XY coordinate and coordinate system information.
The following table summarizes the format specific options and provides hints, tips, and cautions for each of the raster image file formats available to export from Surfer.
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File Extension
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Name
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Format-Specific Options
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Comments
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BMP
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Windows Bitmap
(BMP)
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none
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This is the largest of the raster image export files because there are no compression options.
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EPS
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Encapsulated
Postscript |
embedded
preview |
This is a raster only EPS.
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GIF
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GIF Image
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transparency
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This is a good small-size format for exporting imagery with background transparency. GIF files are limited to a resolution of 72 dpi.
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JP2, J2K,
JPC, JPT, JPEG2000, J2000 |
JPEG-2000 Bitmap
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compression and
container format |
This is a compressed image format with similar properties to JPG, but with greater compression due to container format. The container format reduces the file size without degrading the image.
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JPG, JPEG
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JPEG Compressed Bitmap
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compression
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This is a compressed image format. You can often obtain a nice quality image at a small size with the compression. The more you compress the image, the more the quality of the image is degraded.
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PDF
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PDF (Raster)
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compression
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This format is useful when required to have a PDF (either for distribution or publication) and the vector format PDF is not sufficient.
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PNG
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Portable Network Graphics
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transparency
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This format is often used when transparent backgrounds are required. The file sizes are small, so these are great for publication on the web.
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PNM
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PNM Image
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none
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RAS, SUN
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Sun Raster Image
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none
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This format is common for sharing images between Windows and Unix machines.
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RGB, RGBA
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SGI-RGB Image
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none
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This format is also common for sharing images between Windows and Unix machines.
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TGA
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Targa (TrueVision)
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none
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TIF
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Tagged Image and GeoTIFF
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compression, format
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This is the most commonly exported image file format. GeoTIFFs (TIFs exported with the spatial reference information saved in an internal format) are used widely in other software packages. High resolution TIF images (>=300 dpi) are often exported for print publication.
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X, XIMG
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AVS X-Image
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none
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This format is common for sharing images between Windows and Unix machines.
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image size, resolution, color format and spatial referencing inclusion (real world maps units and coordinate system
information). Some image formats also offer their own additional export options, such as the ability to compress
the image, apply the background transparency, or include a small preview image. These options are
listed in the Format-Specific Options column in the table above.
Vector files contain separate object entities. There is a wide range of vector format types available. Each type contains different information. For example, some formats contain color information, while others do not. Some contain coordinate information, while others do not. Some formats support text and imagery, and others do not. The table below clarifies some ambiguity in these file formats and provides hints, tips and cautions for the various formats. The format you ultimately export depends on what type of data you need and what other application you are going to use the file.
All the vector export formats below support the option to include spatial reference information. Real world XY coordinates can be stored in the file itself. Coordinate system (e.g. projection/datum) information can be stored either internally (e.g. GSB), or in external files such as:
- ESRI .PRJ file
- Golden Software Reference (.GSR and .GSR2) files
Note that ESRI PRJ, GSR and GSR2 files for vector file export only contain coordinate system information and no XY coordinate referencing.
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File Extension
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Name
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Format-Specific Options
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Supported Items
(Text, Images, Drawing Properties, Attributes, Contour Line Z Values) |
Comments
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Best Format to Use With
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BLN
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Golden Software Blanking
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Break apart compound areas
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Attributes
Contour Z value (File | Export) |
A BLN file is a simple boundary file format for points, polylines and polygons. Each object can have one text attribute. This format is used mostly in Surfer for blanking grids, defining fault or breakline traces during gridding, defining the line of section for slicing grids, or for loading as base layers. This is a text format with one simple header row per object, so this format can also be used for exporting XY values.
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Surfer for grid functions (blanking, slicing, gridding with faults/breaklines) and simple boundaries Golden Software applications
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BNA
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Atlas Boundary
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Break apart compound areas
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Attributes
Contour Z value (File | Export) |
A BNA file is a simple boundary file format for points, polylines and polygons. Each object can have two attributes.
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Other mapping applications
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DXF
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AutoCAD DXF Drawing
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File format version
ASCII vs. binary format Color mapping Drawing options |
Text
Images Some Drawing Properties Contour Z value (Map |Export Contours) |
DXF files are a good format choice when transferring data from Surfer to another application. DXF files can contain points, polylines, polygons, text, and can reference imagery and retain most drawing properties. However, no attributes are exported for features in base layers. Most other mapping or drawing applications can read DXF files.
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Other mapping applications
CAD applications |
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GSB
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Golden Software Boundary
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Break apart compound areas
File format version |
Attributes
Contour Z value (File | Export) |
This is another simple boundary file format for points, polylines and polygons. Coordinates, coordinate system and attribute information is saved internally.
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Golden Software applications
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GSI
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Golden Software Interchange
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Write areas as curves
Render text Render marker symbols |
Text
Images Drawing Properties Attributes Contour Z value (File | Export) |
The GSI format is best used when exchanging information between Surfer projects or Golden Software applications (e.g. between MapViewer and Surfer). Virtually all properties of the map are retained.
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Golden Software applications
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KML/KMZ
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Goodle Earth
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Text options
Marker options Area options Curve options Line widths Split compound areas |
Text
Images Drawing Properties Contour Z value (File | Export) |
KML/KMZ formats are best used when transferring map data from Surfer to Google Earth. The KMZ format is the compressed version of KML, so the file size may be slightly smaller. KML/KMZ files are required to be in lat/long units. If your map is not in lat/long units, then a coordinate system must be specified and Surfer will convert the coordinates for you automatically upon export.
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Google Earth
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MIF
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MapInfo Interchange Format
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Write areas as curves
Render text Render marker symbols |
Text
Some Drawing Properties Attributes Contour Z value (File | Export) |
MIFs are a good format choice when transferring data from Surfer to another application. Text, polylines, polygons and points are supported, in addition to attributes, Z values for contour lines, and most drawing properties. Text and marker symbols can be rendered as polygons, if desired.
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Other mapping applications
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PDF
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PDF (Vector) and GeoPDF
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Resize embedded images
Image compression Page size |
Text
Images Some Drawing Properties |
This is used for generating high quality PDFs for use in publications and GeoPDFs for use in other programs. Vector PDFs are generally smaller in size than raster PDFs, and the vector objects (text, lines) are higher in quality and do not degrade with increasing zoom. The text can be edited.
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Publications
Adobe products |
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SEG, SP1
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SEG-P1 Exchange Format
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none
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none
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This file format contains only discrete point data. Points are exported directly to the file. Polylines and polygons are converted to points and exported to the file. This is typically a format used for storing seismic data, or geophysical shotpoint data.
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Geophysical applications
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SHP
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ESRI Shapefile
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Write areas as lines or create a separate file
Write points as lines or create a separate file Render text Render marker symbols Codepage for attribute translation |
Attributes
Contour Z value (File | Export) Contour Z value (Map |Export Contours) |
This is a great format for use in other GIS applications. Attributes and Z values are stored in the associated DBF file. Z values can also be stored in the SHP file itself. Note that SHP files do not contain any drawing information (colors, fills, line styles, etc) and can only contain one feature type per file. The only feature types supported in SHP files are points, polylines, and polygons. So you can have one SHP file with all points in it, another for the polylines, and a third for the polygons. Text and marker symbols can be rendered as polygons.
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Other mapping applications
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SVG
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Scalable Vector Graphics
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none
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Text
Image Drawing Properties |
This is a good format choice when publishing imagery on the web or to another application that supports SVG format. The quality of the original vector objects do not degrade with increasing zoom as it would with a raster image (e.g. PNG, GIF, JPG).
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Web pages
Other applications that support SVG |
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TXT
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3D Text
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none
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Contour Z value (Map | Export Contours)
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This is a great way to get the XYZ coordinates of the vertices along the contour lines. The data file consists of XYZ triplets for each point on each polyline.
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Data processing
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There are two additional formats that are actually a blend of raster and vector data. These are the metafile formats, as listed in the table below. A metafile format is an excellent format to choose when inserting maps into reports and presentations. The inserted image looks almost identical to the appearance of the map in Surfer. Raster data (e.g. image maps, 3D surfaces, imported images) are exported in raster format, while lines and text are exported to the file in vector format. After inserting the metafile into another application, there is no degradation in the vector objects when the image is resized, and storing the vector objects in vector format helps keep the file size small. There is no spatial referencing, coordinate system information, attributes, or Z values exported to a metafile format. When you insert a metafile into Word or PowerPoint, or import it back into Surfer, you can break it apart to access the individual items in the file.
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File Extension
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Name
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Format-Specific Options
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Comments
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Best Formats to Use With
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EMF
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Windows Enhanced Metafile
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resize embedded images
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This is an excellent format to choose when inserting maps into Microsoft Word or PowerPoint. The inserted image looks almost identical to the appearance in Surfer. File sizes are small.
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Microsoft Word or PowerPoint
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WMF
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Windows Metafile
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resize embedded images
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You would only need to use a WMF in place of an EMF if you are inserting the image into an older software program that does not support EMF files.
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Older software
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No spatial reference information, Z values, or attributes are exported.
Common Scenarios
The tables above contain a lot of information. You can read them in depth, or browse the list below of some common scenarios and the recommended export formats.
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Reason for Export
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Recommended Export Format
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| Publication on the web | SVG or PNG |
| Publication in print | TIF (atleast 300 dpi) or vector PDF |
| Insertion into PowerPoint or Word | EMF |
| Use in GIS (and you want attributes) | SHP or MIF |
| Use in GIS (and you want attributes and colors) | MIF |
| Use in GIS/CAD (and you want colors) | DXF or MIF |
| Use in GIS/CAD (and you want Z values of contour lines) | DXF or SHP |
| Use in other Golden Software applications | GSI |
| Use in Google Earth | KML |
| Use as a background image | GeoTIFF or GeoPDF |
Not all your needs may be met with a single file format. Even in one of the situations above, another format may be more suitable to your needs than the one listed as recommended. For more information, see the list of Supported File Formats on the support website. You are also welcome to email surfersupport@goldensoftware.com with any questions.
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