NavCom Rinex Utility Rev C - Manual (Page 13)

RINEX Utility – Rev C
11
Options
Figure 4: Options Area
Completing the Options fields is optional. To modify an option, the box above and/or to the left
must be checked (
9).
Figure 4 shows the Options area of the RINEX Utility.
9 Marker Position: Allows the user to input the Latitude, Longitude, and Height of the surveyed
position in Degrees Minutes and Seconds. These coordinates are converted to Cartesian
ECEF format and inserted into the “Approximate Position XYZ” area of the RINEX
observation file. If left disabled, the RINEX Utility will average the position based on the
range measurements received from the total number of epochs in the data collection period.
‡
RINEX Utility conforms to RINEX Standard 2.10, which states that the Cartesian
ECEF position in the observation file header is WGS84. This means that the
height entered in the RINEX Utility must be WGS84. The RINEX Utility makes no
attempt to convert other datum heights to WGS84. Using height data from a
datum other than WGS84 will result in errors in the Z-axis.
9 Output start time / Output end time: If enabled, the Output Start and Output End times allow
the user to parse a large raw data file into a smaller snap shot of the overall data collection
period. Caveats are that the GPS Week Number, and the GPS Time Of Week (TOW in
seconds) be entered. Refer to the sections below, GPS Week Number and GPS Time, for
details on these values.
If the Output Start and Output End times are disabled, the RINEX Utility will process the
entire data collection period.
GPS Week Number
The GPS Week Number count began at midnight on the evening of 05 January 1980 / morning
of 06 January 1980. Since that time, the count has been incremented by 1 each week, and
broadcast as part of the GPS message. The GPS Week Number field in the data stream is
modulo 1024. This meant that at the completion of week 1023, the GPS Week Number rolled
over to 0 on midnight GPS Time of the evening of 21 August 1999 / morning of 22 August 1999.