What is the SSF file format?
.ssf files are associated with Trimble Navigation (Trimble Inc.), a GPS and GNSS positioning software developer. The .ssf (Standard Storage Format) stores raw field-survey data generated by Trimble data collectors - it is a proprietary binary record stream rather than a conventional database, holding typed records for GNSS positions, feature geometry (points, lines, and areas), attribute values, and session metadata.
.ssf data can be further processed, differentially corrected, and exported to .cor corrected-position files or to formats such as .shp shapefiles via Trimble GPS Pathfinder Office.
.ssf files can be used in 3D modelling of terrain or objects. They are also used for storing and distributing field data in real estate surveying, forestry, and map creation. Because the format is proprietary and binary, files require Trimble GPS Pathfinder Office or a compatible Trimble extension for ArcGIS to open reliably.
Security & safety
RISK: LOWA Trimble SSF is passive logged field data, not executable code, so opening/processing it is safe. The practical cautions are non-malware: SSF is proprietary, so plan to export to an open format (shapefile/GPX) rather than relying on it long-term, and GPS field data can include precise locations, so handle sensitive sites accordingly. Confirm the file is actually Trimble GPS data before installing software for it - the .ssf extension is reused by SongShow Plus and by Steganos Safe (an encrypted container), which need entirely different tools.
Format details
in a nutshell- SongShow Plus song file - Worship-presentation software SongShow Plus uses .ssf for song/lyric files - unrelated to GPS data.
- Esri smooth feature / styling - Some Esri/GIS contexts use .ssf for smooth-feature or style data.
- Steganos Safe encrypted container - Steganos security software has used .ssf for an encrypted virtual-safe container.
Programs that open SSF files
Windows4 apps
Trimble GPS Pathfinder Office
Paid Import the .ssf, differentially correct it, then export features to shapefile/GPX. The primary tool for SSF.
Trimble Positions / TerraSync (data collection)
Paid Trimble field/desktop software that writes and reads SSF within the Pathfinder workflow.
ArcGIS Desktop / ArcGIS Pro (with Trimble extension)
Paid Use the corrected/exported data (shapefile) in ArcGIS; SSF itself is brought in via the Trimble Pathfinder/Positions tooling.
QGIS (after export)
Open-source Open the shapefile/GPX exported from SSF - free GIS viewing/editing. QGIS does not read SSF directly. Technical details
deep spec| Format type | Proprietary binary GPS/GNSS field-survey data file |
| Encoding | Binary (proprietary Trimble record stream; byte layout not publicly documented) |
| Record structure | Sequence of typed records: GNSS position fixes, feature geometry (point, line, area), attribute values, and session header/metadata |
| GNSS logging interval | Configurable on the data collector; commonly 1 s or 5 s position epochs |
| Coordinate reference | WGS-84 (raw GNSS); datum transformations applied during post-processing in Pathfinder Office |
| Feature geometry types | Points, lines, and areas (polygons); aligns with standard GIS vector feature types |
| Differential correction | Supported - base-station or WAAS/SBAS correction applied in Trimble GPS Pathfinder Office, producing a corrected `.cor` output file |
| Typical file size | Tens of KB to a few MB per field-data session |
| Post-processing software | Trimble GPS Pathfinder Office (Windows desktop application) |
| Export formats | Shapefile (`.shp`), GPX, DXF, and other GIS/CAD formats exported from Pathfinder Office |
| Platform | Windows (desktop post-processing); legacy Trimble data collectors ran Windows Mobile / Windows CE |
| MIME type | application/octet-stream (no format-specific MIME type registered) |
| File identification | Identified by file origin (Trimble GPS receiver, TerraSync, or Pathfinder data collector); no public magic-byte signature has been documented for this proprietary format |
| Attribute data | Supports named feature attributes (text, numeric, menu) defined in a data dictionary (`.ddf`) file loaded on the collector before the survey session |
| Format versioning | Format version is implicit in the Trimble data-collector firmware and Pathfinder Office release that wrote the file; no explicit version field is exposed in the public interface |
| Released | 1990s (Trimble GPS data-collection / Pathfinder ecosystem) |
| Latest version | N/A (legacy field-data format within Trimble's GPS Pathfinder / TerraSync workflow) |
| Specification | www.trimble.com |
SSF conversions
Community Q&A
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