UNB3 data management script assessment

1. UNB3 data management script assessment Thatchineswaran Thirumurthi, Landon A. Urquhart, Richard B. Langley, and Rodrigo F. Leandro

2. Table of Contents • Introduction to UNB3 • Logging of UNB3 data • UNB3 data management script • Comparison of C2 and P2 acquisition by UNB3 • Tracking of P2 signal by UNB3 and UNBJ • Conclusions

3. Introduction to UNB3 • UNB3 station is located at the roof of Head Hall, UNB, Fredericton. • UNB3 currently uses a Trimble NETR5 receiver. It used to operate using a Trimble R7 receiver earlier. • UNB3 receiver is owned by Trimble Navigation Ltd., and operated by UNB (Rodrigo, Richard, Liliana). • It is part of the IGS L2C-Test network. • UNB3 shares a Javad Antenna (JPSREGANT_DD_E NONE) with IGS Station UNBJ.

4. Logging of UNB3 files • The UNB3 files are stored in a binary format (.t01) in Trimble NETR5 receiver. • The data from Trimble NetR5 receiver was sent in real-time (RT17 format) to Cansel where using GPSNet, RINEX files were generated. • It was preferred that *.t01 files from Trimble receiver be converted into RINEX format at UNB and supplied to CDDIS instead of using Cansel’s GPSNet (No RT communication issues).

5. UNB3 data management script • The data management script was modified to obtain the T01 hourly files directly from Trimble NETR5 receiver and uses t012rin (an unreleased Trimble utility provided to UNB) to convert them into hourly RINEX files. • In the Summer of 2007, the new UNB3 data management procedure was tested by two students, Landon and Thatchan. • Assessment objective: check if the new effective procedure was working properly.

6. UNB3 data management script • Loss of satellite data at certain epochs were noticed in RINEX files produced by Cansel’s GPSNet compared to files produced by the new script that uses t012rin. Reason: communication drops.

7. UNB3 data management script - FUTURE • Trimble has providedto UNB a new utility (ConvertToRinex) which records SBAS data in addition to GNSS data. • After successful testing, it is intended to replace ‘t012rin’. • UNB has helped in the assessment of some unreleased Trimble utilities/firmware.

8. Comparison of C2 and P2 acquisition by UNB3 • It was found that, as expected, C2 (L2C (M+L)) signal was acquired at a lower elevation angles compared to P2 (semi-codeless L2 P(Y)) signal.

9. Tracking of P2 signal by UNB3 and UNBJ • UNBJ tracks P2 signals at a lower elevation compared to UNB3(both are semi-codeless L2 P(Y)). • It could be due to the splitter arrangement. 2.8º ± 0.3º 8.3º ± 1.5º

10. Conclusions • We have verified that the new data management works properly; • We have made a brief L2C signal tracking assessment, and the results are as expected; • In the near future there will be a new procedure, using the latest ConvertToRinex utility. The assessment of the new procedure is its final stage.