GNSS Baseline Data Sources
The baseline processor uses measurements made by GNSS receivers to compute baselines. These measurements can be stored and referenced in a variety of file formats that are outlined in Import Data Formats and Export Data Formats, as well as formats from other manufacturer’s receivers (RINEX).
In addition to GNSS measurements, these sources also provide information that is used to determine how the GNSS measurements should be processed, such as when a receiver is stationary at a point, or when it is roving. This allows the baseline processor to categorize the GNSS measurements as shown below:
- Static / FastStatic
- Roving and continuous kinematic data
- Stop and go kinematic data
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Baseline Collection Methods |
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Total measurement time of the occupations |
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| Static
A long, stationary occupation over a single point |
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| FastStatic
Shorter, stationary occupations over multiple points with no data collected between them |
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| Kinematic
Short, stop and go occupations with roving or continuous data between them |
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Trimble data collector files
These files typically contain information obtained during conventional surveys. The Trimble data collector files can be used to reference GNSS measurements used for post-processing when radio communication is not possible. In this case, the point information is stored in the data collector file and raw GNSS measurements are stored in a related .dat file for later processing. The GNSS measurements referenced by the data collector file are used by the baseline processor to compute baselines that could not be solved in real time.
Although the GNSS measurements are stored in separate .dat files, they can be loaded automatically by the import procedure because of the references in the data collector file itself. They do not have to be loaded as independent files.
Data collector files can include measurements collected during several survey sessions, each session potentially using different survey methods.
Trimble receivers
These files contain the measurements obtained by a Trimble receiver. These files are typically recorded to the receiver memory board, or to a memory card in a Trimble data collector. These files are downloaded from the survey device for processing. The measurements contained in these files are used by the processor to compute baselines using static, FastStatic and kinematic techniques.
Other receiver manufacturers
These files contain measurements obtained by a GNSS receiver. They are similar in content to .dat files, but are stored in the Receiver INdependent EXchange format (RINEX). The RINEX format is an ASCII representation of GNSS data collected by receivers. RINEX files include observation, navigation, and meteorological data.
RINEX files are typically obtained from base stations, such as from the IGS Tracking Network , the Continuously Operating Reference Stations (CORS) in the United States, or from other manufacturers’ software. The processor uses these files just as it does .dat files to obtain vector baseline solutions.
