SBF files can be cropped using the sbf2sbf command line tool which is part of Septentrio's post-processing software PP-SDK. Assuming a standard installation, the tool can be found in the folder \\PPSDK\tools\binaries. The cropping of SBF files involves the following steps:
First, to crop the SBF file to a specific interval, it is necessary to know the GNSS time in seconds of the start and end time of the period of interest. To determine the time frame in GNSS seconds, the SBF file can be opened in SBF analyzer. Go to File > Preferences > Units and change the “Time Frame/Representation” option to “GNSS time (seconds)” as shown in Figure 1.
Figure 1: Selection of GNSS time in seconds in Preferences
Now, any SBF block (e.g. Carrier to Noise) can be selected and analyzed to note down the GNSS time at the beginning and end of the file.
Next, copy the sbf2sbf.exe windows console application to the folder which contains the SBF file to be cropped. Open the console and input the following command, using the start time and end time (without decimals) recorded during the previous step:
sbf2sbf -f inputfile.sbf -Q Begintime:Endtime -o outputfile.sbf
Figure 2: sbf2sbf command line tool in command prompt
After executing the above command, the output SBF file should now contain only the data of the period of interest.
There are several ways to merge two or more sbf files. The simplest of these is to use the copy option, similar to the cropping command, in the command prompt as shown below
copy /b file1.sbf+file2.sbf merged_file.sbf
Figure 3: Merging two SBF files using command prompt