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NavCom Technology, Inc.
20780 Madrona Avenue
Torrance, California 90503 USA
Tel: +1 310.381.2000
Fax: +1 310.381.2001
sales@navcomtech.com
www.navcomtech.com
P/N: 9
310021-2101
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RINEX Utility – Rev C
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RINEX Utility – Rev C
Table of Contents
List of Figures.............................................................................................................................ii
List of Tables...............................................................................................................................ii
Notices........................................................................................................................................iii
Copyright..............................................................................................................................................iii
Trademarks ..........................................................................................................................................iii
User Notice...........................................................................................................................................iii
Revision History.........................................................................................................................iv
Use of this Document.................................................................................................................v
Overview of the RINEX Utility ....................................................................................................7
File I/O..........................................................................................................................................8
RINEX File Naming Conventions.............................................................................................................9
User Input..................................................................................................................................10
Options ......................................................................................................................................11
GPS Week Number ...............................................................................................................................11
GPS Time ..............................................................................................................................................12
Execution and Progress...........................................................................................................14
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RINEX Utility – Rev C
List of Figures
Figure 1: NavCom RINEX Utility...................................................................................................7
Figure 2: Input File and Output Directory......................................................................................8
Figure 3: User Input Area............................................................................................................10
Figure 4: Options Area................................................................................................................11
Figure 5: Output Interval and Ephemeris Output........................................................................13
Figure 6: Antenna Type ..............................................................................................................13
Figure 7: Progress of RINEX Conversion...................................................................................14
List of Tables
Table 1: RINEX Utility Defaults.....................................................................................................8
Table 2: GPS Time .....................................................................................................................12
ii
Notices
RINEX Utility User Guide
P/N 96-310021-2101
Revision C
February 2009
RINEX Utility – Rev C
Serial Number:
Date Delivered:
Purchased From:
Copyright
© 2009 by NavCom Technology, Inc.
All rights reserved. No part of this work or the computer program(s) described herein may be
reproduced, stored, or transmitted by any means, without the expressed written consent of the
copyright holders. Translation in any language is prohibited without the expressed written
consent of the copyright holders.
Trademarks
‘find your way’, ‘NavCom Globe’ and ‘NAVCOM TECHNOLOGY’ logos are trademarks of
NavCom Technology, Inc. StarFire™ is a registered trademark of Deere & Company. All other
product and brand names are trademarks or registered trademarks of their respective holders.
User Notice
NavCom Technology, Inc. shall not be responsible for any inaccuracies, errors, or omissions in
information contained herein, including, but not limited to, information obtained from third party
sources, such as publications of other companies, the press, or competitive data organizations.
This publication is made available on an “as is” basis and NavCom Technology, Inc. specifically
disclaims all associated warranties, whether express or implied. In no event will NavCom
Technology, Inc. be liable for direct, indirect, special, incidental, or consequential damages in
connection with the use of or reliance on the material contained in this publication, even if
advised of the possibility of such damages. NavCom Technology, Inc. reserves the right to
make improvements or changes to this publication and the products and services herein
described at any time, without notice or obligation.
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RINEX Utility – Rev C
Revision History
Format change.
Updated graphics.
Described new feature, the Antenna Type drop-down list.
Added MEAS1B, PVT1B, and ALM1B to the list of NCT messages that
Rev C (Feb 2009)
Rev B (Dec 2006) Updated graphics; updated ‘Known Issues’; Format change
Rev A (Jun 2006) Initial release
the RINEX Utility converts to the RINEX V2.1 format.
Deleted the ‘Known Issues’ section – these 2 issues fixed in this
software release (v1.27): The error message, “No Valid Observation
Available”, no longer appears during the conversion process. When the
user manually enters a Marker Position into RINEX, the resulting OBS
file’s XYZ Positions are now correct.
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RINEX Utility – Rev C
Use of this Document
This User Guide is intended to be used by someone familiar with the concepts of GPS and
satellite surveying equipment.
Note indicates additional information to make better use of the product.
This symbol means Reader Be Careful. Indicates a caution, care, and/or safety
situation. The user might do something that could result in equipment damage or
loss of data.
This symbol means Danger. You are in a situation that could cause bodily injury.
Before you work on any equipment, be aware of the hazards involved with
electrical and RF circuitry and be familiar with standard practices for preventing
accidents.
Revisions to this User Guide can be obtained in a digital format from
http://www.navcomtech.com/Support/DownloadCenter.cfm?category=manuals
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RINEX Utility – Rev C
Overview of the RINEX Utility
The RINEX Utility converts NCT (NavCom Technology) binary raw data (0xB0, 0xB1, 0x44,
MEAS1B, PVT1B, and ALM1B messages) to RINEX v2.1 format. Converting NCT raw data to
RINEX provides a means to post-process the raw data when third party software packages do
not support the NCT Binary format, but do possess the ability to import RINEX Standard
measurement data.
Most post-processing programs require a minimum of 60 minutes of data to
process and almanac and ephemeris data at the beginning of the file.
Figure 1: NavCom RINEX Utility
The NCT RINEX Utility GUI is divided into four major areas:
9 File I/O
9 User Input
9 Options
9 Execution and Progress
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RINEX Utility – Rev C
File I/O
Figure 2: Input File and Output Directory
Refer to Figure 2 for the steps below:
9 Click the Input File button to navigate to and select the NCT binary raw data file (*.dat) to be
converted to the RINEX v2.1 format.
9 Click the Output Directory button to select the folder to save the converted files. The RINEX
Utility converts the NCT data file into two RINEX files, one with GPS navigation data and
the other with observation data (refer to the section below, RINEX File Naming
Conventions).
The conversion options available in the User Input and Options areas of the RINEX
Utility window are not always necessary to complete the conversion. However, selecting
the appropriate Antenna Type is always recommended to obtain the best results (see
Figure 6).
If the user enters conversion options, the headers of the RINEX files display the user
specific information. If the user does not enter options, the headers display the default
information shown in Table 1.
Table 1: RINEX Utility Defaults
Leap Seconds 0 or Last Entered
Marker Name None or Last Entered
Antenna Height 0.0 or Last Entered
Marker Position Disabled
Output Times (Start and End) Disabled
Sat Ephemeris when Available Disabled
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RINEX Utility – Rev C
9 These conversion options are available:
• User Input: Marker Name, Leap Seconds, and Antenna Height Above Marker
• Options: Marker Position, Output Start / End Times, Antenna Type, Output Interval, and
Ephemeris Output
Refer to the sections below, User Input and Options, for details.
9 If no conversion options are desired, click the Start button to generate the RINEX files.
RINEX File Naming Conventions
RINEX requires the file naming convention to follow a specific format. The easiest way to relate
files is to use the same naming convention for all related files in a given directory and to use
separate directories for files recorded on the same date. The file naming convention is:
9 File names are limited to 8 characters followed by a 3 character extension (MS-DOS
compatible; ssssddd0.yyt)
9 ssss = a unique file identifier. All four characters must be used. If less than 4 characters are
used, enter “_” (underscore) to fill the space. Any alpha-numeric character is acceptable (AZ and 0 -9).
If the name of the data file is longer than four characters, it is truncated when the
RINEX files are generated. For example, “cnav8b.DAT” becomes “cnav”.
9 ddd = the Julian date of the year; i.e. March 23, 2007 = Julian date 082
9 0 = required fill character
9 yy = last two digits of the calendar year
9 t = file type; the output files will be tagged as either O for observation or N for navigation, for
example, “cnav0820.07N” and “cnav0820.07O”.
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RINEX Utility – Rev C
User Input
Figure 3: User Input Area
Completing the User Input fields is optional. Entries in these fields are included in the headers of
the RINEX navigation or observation files.
Figure 3 shows the User Input area of the RINEX Utility.
9 Marker name: Allows up to 60 characters to identify the site where the data was collected.
9 Leap seconds: Allows the user to insert the current GPS Leap Second value, if known. If left
blank no leap second value will be reported in the RINEX ephemeris (navigation) file
header, or the RINEX Utility will use the leap second time reported in the raw data file (if one
exists). If the raw data file has a larger leap second value reported than the user entered
value, the raw data file value will be used instead.
9 Antenna height above marker: Allows the user to insert antenna base height above the
survey point. This adjustment can often be made in the Post Processing Software package
as well.
10
Options
RINEX Utility – Rev C
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.
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RINEX Utility – Rev C
The NCT-2000D and NCT-2100D use an adjusted 16-bit integer (U16) in the data to avoid this
confusion. They can handle up to week 65535.
For example, in Figure 4 the GPS Week Number for the Output Start / End times is 1313. To
determine the week/date, subtract 1024 from 1313, which is 290. Then add 290 weeks to 21
August 1999. The result is Sunday 6 March 2005.
GPS Time
The GPS time (seconds into the week) always starts on Sunday morning at 00:00 GMT. Each
24 hour period contains 86,400 seconds. A full week contains 604,800 seconds. Please see the
table below for a breakdown of hourly / daily increments.
Table 2: GPS Time
GMT Sun Mon Tue Wed Thu Fri Sat
0:00:00 0 86400 172800 259200 345600 432000 518400
1:00:00 3600 90000 176400 262800 349200 435600 522000
2:00:00 7200 93600 180000 266400 352800 439200 525600
3:00:00 10800 97200 183600 270000 356400 442800 529200
4:00:00 14400 100800 187200 273600 360000 446400 532800
5:00:00 18000 104400 190800 277200 363600 450000 536400
6:00:00 21600 108000 194400 280800 367200 453600 540000
7:00:00 25200 111600 198000 284400 370800 457200 543600
8:00:00 28800 115200 201600 288000 374400 460800 547200
9:00:00 32400 118800 205200 291600 378000 464400 550800
10:00:00 36000 122400 208800 295200 381600 468000 554400
11:00:00 39600 126000 212400 298800 385200 471600 558000
12:00:00 43200 129600 216000 302400 388800 475200 561600
13:00:00 46800 133200 219600 306000 392400 478800 565200
14:00:00 50400 136800 223200 309600 396000 482400 568800
15:00:00 54000 140400 226800 313200 399600 486000 572400
16:00:00 57600 144000 230400 316800 403200 489600 576000
17:00:00 61200 147600 234000 320400 406800 493200 579600
18:00:00 64800 151200 237600 324000 410400 496800 583200
19:00:00 68400 154800 241200 327600 414000 500400 586800
20:00:00 72000 158400 244800 331200 417600 504000 590400
21:00:00 75600 162000 248400 334800 421200 507600 594000
22:00:00 79200 165600 252000 338400 424800 511200 597600
23:00:00 82800 169200 255600 342000 428400 514800 601200
23:59:59 86399 172799 259199 345599 431999 518399 604799
Example: 518400 = Sat 0:00:00 GMT
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RINEX Utility – Rev C
Figure 5: Output Interval and Ephemeris Output
9 Ephemeris Output: If enabled, outputs the ephemeris (navigation) file, but only with
ephemeris data for those satellites that have been tracked over the data collection period. If
disabled the ephemeris file will contain data on all satellites.
9 Output Interval: Select the output interval in seconds to decimally parse the data, if desired.
Figure 6: Antenna Type
9 Antenna Type: Select the antenna type used to collect the data. Figure 6 identifies the
NavCom antennae available in the drop-down list:
• NAVAN2004T: The standard integrated antenna (PN: 82-
001002-3002). It tracks all GPS, WAAS/EGNOS/MSAS/GAGAN
and StarFire™ signals. Our compact GPS antenna has
excellent tracking performance and a stable phase center for
GPS L1 and L2. This antenna is listed in the NOAA GPS
Antenna Calibration tables, as NAVAN2004T.
• NAVAN2008T: The airborne integrated antenna (PN: 82-
001002-3001). It tracks all GPS, WAAS/EGNOS/MSAS/GAGAN
and StarFire™ signals. Our compact GPS antenna has
excellent tracking performance and a stable phase center for
GPS L1 and L2. This antenna is listed in the NOAA GPS
Antenna Calibration tables, as NAVAN2008T. It is included with
the VueStar system, and is an option for many (but not all)
NavCom GPS receivers.
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RINEX Utility – Rev C
Execution and Progress
The Start button engages the conversion process, which can be stopped at any time by clicking
the Cancel button. The Exit button closes the utility at any time, including during program
execution, thereby canceling the process.
Figure 7: Progress of RINEX Conversion
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