08.06.2013 Views

Bernese GPS Software Version 5.0 - Bernese GNSS Software

Bernese GPS Software Version 5.0 - Bernese GNSS Software

Bernese GPS Software Version 5.0 - Bernese GNSS Software

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

4. Import and Export of External File Formats<br />

files should, therefore, only be used within the <strong>Bernese</strong> <strong>GPS</strong> <strong>Software</strong> because a RINEX<br />

file should contain raw measurements.<br />

Either <strong>GNSS</strong> code and/or phase observations or ranges (SLR) may be converted (option<br />

“Measurement types to save” in panel “RXOBV3 1”).<br />

A station coordinate file may be updated or created based on the coordinates specified in<br />

the RINEX headers by specifying a filename in option “Update coordinates”. Coordinates of<br />

stations that are not included in this file are added with coordinate flag “R”.<br />

Further options concerning the data selection are provided in panel “RXOBV3 2: Input Options<br />

1” (Figure 4.2). Option “Satellite system to be considered” (<strong>GPS</strong>, GLONASS, or ALL) allows<br />

to reduce the data amount by selecting only the observations you are interested in. In<br />

addition you may specify an observation window in panel “RXOBV3 3: Observation Window”.<br />

The default sampling rate within the IGS is 30 seconds but there may be stations which<br />

have a higher sampling rate (e.g., 10 seconds). You may define the sampling for the <strong>Bernese</strong><br />

observation files in option “Sampling interval” in panel “RXOBV3 2: Input Options 1”. If the input<br />

field is left empty or the value is set to 0 all observations from the RINEX file are converted.<br />

The selected sampling rate is counted starting with an offset which you may specify in option<br />

“Sampling offset to full minute”. If you, e.g., sample 10 seconds data to 60 seconds and specify<br />

an offset of 10 seconds the observation epochs of the resulting <strong>Bernese</strong> observation file will<br />

be 10 sec, 70 sec, 130 sec, etc. Note, that the current version of the <strong>Bernese</strong> <strong>GPS</strong> <strong>Software</strong><br />

does not process data with sampling higher than 1 Hz.<br />

The panel “RXOBV3 4: Input Options 2” (Figure 4.3) addresses input options concerning signal<br />

strength requirements, observation number, and antennas. The option “Minimum signal<br />

strength” can be used to eliminate data with a low signal-to-noise ratio. According to the<br />

RINEX format definition the signal-to-noise ratio is mapped into values from 0 to 9. A value<br />

of 0 means either a bad observation (some RINEX converter use it like this) or an unknown<br />

signal-to-noise ratio. If you use original RINEX files it is recommended to use all available<br />

observations by accepting all available signal-to-noise ratios. Bad observations in the data<br />

will be identified and excluded in the further processing.<br />

You may, in addition to the above option, activate “Accept signal strength = 0” to keep data<br />

with a signal strength of 0. This is recommended and makes sense if you wish to exclude<br />

observations with low signal-to-noise ratio but want to process observations with unknown<br />

quality.<br />

If you have preprocessed the RINEX files with program RNXSMT (see Section 6.2) you have<br />

to set option “Minimum signal strength” to 2 in order to eliminate bad observations (marked<br />

by program RNXSMT with a signal strength of 1, see Section 6.2). You should also disable<br />

option “Accept signal strength = 0” in this case.<br />

Cycle slip flags from RINEX can be accepted by enabling the option “Accept cycle slip flags<br />

from RINEX”. This option is available for processing zero difference phase observations. If<br />

the RINEX files are already cleaned, e.g., by the program RNXSMT, then it is possible to<br />

accept the cycle slip flags. Cycle slip flags from original RINEX files should, however, not be<br />

accepted due to their potentially large number and because they will be reliably identified<br />

in any case in the preprocessing procedures available in the <strong>Bernese</strong> <strong>GPS</strong> <strong>Software</strong>.<br />

The exclusion of stations providing a small number of epochs is possible using “Minimum<br />

number of epochs requested per file”. Note that stations may also be excluded by adding a cor-<br />

Page 56 AIUB

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!