Facility. Development and Testing. What s Next? GNSS Modernization and Next Generation Hardware for the UNAVCO Community

Transcription

1 Facility Development and Testing What s Next? GNSS Modernization and Next Generation Hardware for the UNAVCO Community Frederick Blume UNAVCO Science Workshop, 9 March, 2010

2 Motivation Last formal hardware evaluation done by UNAVCO in 2003 (PBO RFP) CPU, data storage, communications technology has improved GNSS modernization brings new observables, frequencies and constellations incompatible with older hardware. Community Pricing Agreements Depended on PBO Purchases 5-year agreements with Trimble and Topcon expired in 2008, carried forward at manufacturer s discretion Tiered pricing structure based on total quantity purchased by Community semi-annually makes project planning difficult. Workhorse affordable receiver (Trimble NetRS) no longer available. Keep existing network infrastructure functioning without breaking the bank What new features are important vs. simple plug & play replacement? Compatibility with existing data retrieval systems. Compatibility with existing GPS/GNSS antennas. Compatibility with physical infrastructure (power, enclosures, cabling).

3 Evaluation Process UNAVCO Re-establishing Development and Testing Effort Manager appointed 2009 (50% FTE) D&T Engineer to be hired Q Establish (and reestablish) high level technical and sales contacts with GNSS hardware manufacturers. Educate manufacturers of specific community needs and wants. Learn what is currently available and what is under development. Seek partnerships and participation in new system development n-disclosure Agreements in place and pending All manufacturers willing to modify firmware in response to UNAVCO feedback to some extent. To date, meetings held with Trimble, Topcon, Leica, Ashtech, and Septentrio. Formal Request for Information and Community Pricing Upcoming Encourage competition for UNAVCO community purchases. Will prioritize formal evaluation based on community feedback. Moving target is a problem: new models constantly introduced.

4 GPS Signal Evolution L2C: Civilian code on L2 carrier broadcast by 8 Block IIR-M SV s since (7 healthy) Unencrypted code significantly improves receiver service of scientific and commercial dual frequency users. Provides 24 db better protection than C/A against code cross correlation and interference. L5: Third carrier frequency Demonstration signal launched 3/2009 on PRN01 (SVN49) Needed to reserve L5 with ITU. 10 Block IIF SV s to carry L5 3 in 2010 Launches complete by 2013

5 GPS Signal Evolution L2C Current carrier phase software (e.g. GAMIT) uses first-generation GPS observables only (L1 and L2 phases for C/A or P-codes) Timetable for L2C and L5 development TBD New observables useful for real-time and special applications only? L2C implementation on current receivers allows for low elevation tracking where lock would otherwise be lost. L2C and L5 use Quadrature PSK Modulation ¼-wavelength shift between P2 phase and C2 Some receivers remove this in raw data Trimble, Ashtech Others Don t Standard sought by IGS IC Critical to investigate the effect of L2C tracking on positioning. PBO implemented L2C tracking on several stations in 2010 Teqc modified to explicitly select C2 vs. P2 phases in RINEX files effect on position seen in PBO time series or limited short-baseline processing.

6 GPS Signal Evolution L5 L5 Improves signal structure for enhanced performance Third Frequency 1, MHz (25.5 cm; L1=19 cm, L2 = 24.4 cm) Higher power ( dbw), broad bandwidth (24 hmz) Improved ionospheric delay correction capabilities, Better interference protection and integrity, Instantaneous carrier phase accuracy and ambiguity resolution for cm level measurements, Improved multipath performance Improved multiple access signal cross-correlation statistics. Antenna Compatibility Legacy choke ring antennas can receive L5 (-9 db-hz), but no PCV s yet. In-situ LNA replacement upgrades a TRM to TRM L5 L2 Gal L2 SBAS L1 Glo L1

7 Technical Issues Hardware design flaw in GPS L5 demonstration satellite (PRN01, SVN49) demonstrates problems. Block IIR-M SV launched March 2009 to secure L5 frequency band with ITU. Marked unhealthy August 2009 due to secondary transmissions introduced by new hardware, future still under consideration. Similar issues CANNOT be determined pre-deployment. Problem likely unique to this SV Large Elevation-dependent pseudorange errors introduced by internally reflected transmissions These errors are receiver-dependent!

8 GNSS Modernization The Constellations GNSS (Global Navigation Satellite Systems) Constellations GPS: USA, SVs, 2 orbits every 1 sidereal day, CDMA 11 IIA + 12 IIR + 8 IIR-M (L2C) Last launch 8/2009 Block IIF launch (L5) May 2010 GLONASS: Russia, SVs, 17 orbits every 8 sidereal days, FDMA 18 fully operational + 1 L1-only + 2 in maintenance mode 6 more launches scheduled Galileo: ESA, SVs, 5 orbits every 3 sidereal days, CDMA GIOVE-B only Full constellation 2014? Beidou-2/Compass: China, 30 MEO + 5 GEO SVs, MEO at 13 orbits every 7 sidereal days, CDMA 2 GEO VEs (1 operational) + 3 GEO + 1 MEO Asia coverage201 SBAS: geosynchronous = 1 orbit every 1 sidereal day, CDMA WAAS - USA (4) EGNOS - ESA (4) MSAS - Japan (2) GAGAN - India (2)

9 GLONASS GLONASS Available w Who Should Use It? Operational but years (decades) behind schedule. ~5 year SV life-span; more frequent launches. Orbit accuracy lower Antenna PCV s are frequency dependent GLONASS is FDMA, different frequency per SV GLONASS use degrades GPS position Real-time and post-processed Precise orbits from IGS are available. SV clock corrections Software from NGS under development Track (high-rate) Support under development Real-time receiver corrections are useful

10 GLONASS You should use GLONASS if:

11 GLONASS You should use GLONASS if you have limited sky view. and need a fix

12 GLONASS (from presentation by Tim Springer ESOC, AGU Fall Meeting, San Francisco, 2007)

13 GNSS Modernization Optimistic Deployment Timeline (1-4 year delays?)

14 GNSS Modernization What we re used to:

15 GNSS Modernization Where we re heading: ~2015

16 GNSS Modernization Overlap/interference/interoperability between constellations L5, Galileo, COMPASS share same frequency band, allocated by ITU. New cold war? Galileo and Compass competing and/or collaborating? New Signals can t be evaluated on new hardware until after launch Millimeter precision requires extensive analysis on many fronts Antenna calibrations: Absolute phase center Receiver testing: Tracking, code/phase differences between manufacturers. Orbit post processing (GLONASS orbit determination still not routinely used after 12 years).

17 GNSS Modernization Software Data formats (open & proprietary) Handling large numbers of new observables in raw, BINEX, and RINEX formats requires new format specs, modifications to translation software. Data Flow, Archiving Integration of new signals into archiving routines is non-trivial High-precision processing routines (including orbits) GAMIT, GIPSY, Bernese all use dual freq GPS, must be modified for new GPS signals and other systems Quadrature phase-shift keying introduces differences in phase observables in same frequency (e.g. L2C tracking vs. P2 tracking) and are handled differently by different receivers. Thorough testing of real-time and post-processed positions required RTCM 3.1 standard under development Behavior of new frequencies in ionosphere and troposphere not predictable to high-precision levels. Extensive post-launch analysis will be required to develop new models to be used for high-precision positioning.

18 New GNSS Receivers General evaluation in progress of current top-of-the-line receivers: All multi-use : Reference Station, Campaign, RTK Ashtech ProFlex CORS (née Magellan ProFlex 500) Leica GRX1200+ Septentrio PolaRx3eG Pro Topcon Net-G3A Trimble NetR8 Hardware on display during Wednesday Afternoon UNAVCO Facility Tour

19 New GNSS Receivers Important Features to be Considered Include: Conforms to IGS Considerations for Future IGS Receivers Criteria Tracking characteristics, multipath, many other data quality factors. Rugged Design Heat and cold resistant Power Consumption Internal batteries for campaign/rtk uses GNSS Signals GPS L2C, L5 GLONASS Galileo, Compass (i.e. Future Proof ) User Interface Characteristics Accessible via internet, web interface Cross platform capability Scriptable command-line control language Data Logging and Access High rate performance Multiple logging sessions, separate memory buffers Memory size, configuration, expandability (critical for high-rate) Directory structure, file naming options, server options (e.g. ftp push) Available data formats (Binex, proprietary formats compatible w/teqc) Other Support for meteo, tilt meters, and other serial devices Responsiveness of manufacturer, willingness to collaborate on development Price

20 New GNSS Receivers Receiver Comparison Trimble NetRS Baseline Trimble NetRS Trimble NetR8 Topcon Net-G3A Ashtech ProFlex CORS Leica GRX1200+ Septentrio PolaRx3eG PRO Power Low Power (<5 Watts) Internal Battery/UPS (Campaign) Interface/Control Ethernet Web Server (full control) Limited Future Firmware/Current GUI ftp Server ftp push notification Scriptable Command-line interface Limited Remote firmware upgrade Built in Ntrip Built-in PPP Other serial communications Limited DynDNS Client Storage USB Host (external data storage) * - NO remote access Removable CF card - 2 GB Max - 1 GB Max Fixed Internal memory size 1 GB 4 GB CF Only 128 MB 256 MB 2 GB Signals GLONASS GPS L5 Future Firmware GPS L2C Tracking limitations ne 3 Codes/SV (e.g. C1, P2, C5) ne L2-P OR L2C (t both) ne L2C OR L5, not both Galileo Data Logging Multiple Sessions Configurable memory buffer Future Firmware Future Firmware Future Firmware High-rate 10 Hz* (S/N, PR less) 50 Hz* (S/N, PR less) 100 Hz 20 Hz 20 Hz 20 Hz Met Support Binex support (7f-03) (7f-05) (7f-05) TCP Streaming Other Unique Features file push Internal GSM Modem Spectrum Analyzer Detailed Constellation Info Anti-Interference Filter Upgradeable GNSS Board

21 Ashtech ProFlex CORS Ashtech independent from Magellan January 2010 Eager to reestablish relationship with UNAVCO Community Responsive to feedback on beta products Ashtech ProFlex CORS Power Low Power (<5 Watts) Internal Battery/UPS (Campaign) Interface/Control Ethernet Web Server (full control) ftp Server ftp push notification Scriptable Command-line interface Remote firmware upgrade Built in Ntrip Built-in PPP Other serial communications DynDNS Client Storage USB Host (external data storage) Removable CF card Fixed Internal memory size Signals GLONASS GPS L5 GPS L2C Tracking limitations Galileo 128 MB L2-P OR L2C (t both) Data Logging Multiple Sessions - 2 Configurable memory buffer Future Firmware High-rate 20 Hz Met Support Binex support TCP Streaming Other Unique Features Internal GSM Modem

22 Leica GRX1200+ Advanced web interface Binex capability and multiple ring buffers ATHENA Pricing Program for Educational and non-profit organizations Leica GRX1200+ Power Low Power (<5 Watts) Internal Battery/UPS (Campaign) Interface/Control Ethernet Web Server (full control) ftp Server ftp push notification Scriptable Command-line interface Remote firmware upgrade Built in Ntrip Built-in PPP Other serial communications DynDNS Client Storage USB Host (external data storage) Removable CF card Fixed Internal memory size Signals GLONASS GPS L5 GPS L2C Tracking limitations Galileo - 1 GB Max 256 MB ne Data Logging Multiple Sessions - 2 Configurable memory buffer High-rate 20 Hz Met Support Binex support (7f-05) TCP Streaming

23 Septentrio PolaRx3eG PRO Small, flexible company focused on development and special applications. Spinoff from IMEC Belgium. Unique features such as spectrum analyzer/adaptive interference mitigation. Septentrio PolaRx3eG PRO Power Low Power (<5 Watts) Internal Battery/UPS (Campaign) Interface/Control Ethernet Web Server (full control) ftp Server ftp push notification Scriptable Command-line interface Remote firmware upgrade Built in Ntrip Built-in PPP Other serial communications DynDNS Client Storage USB Host (external data storage) Removable CF card Fixed Internal memory size Signals GLONASS GPS L5 GPS L2C Tracking limitations Galileo Data Logging Multiple Sessions Configurable memory buffer High-rate Met Support Binex support TCP Streaming Other Unique Features Future Firmware/Current GUI 2 GB L2C OR L5, not both Future Firmware 20 Hz Spectrum Analyzer Anti-Interference Filter Upgradeable GNSS Board -35 db

24 Topcon Net-G3A Highly configurable with GRIL command-line language USB Host with unlimited storage capacity Future-proof constellation capability Topcon Net-G3A Power Low Power (<5 Watts) Internal Battery/UPS (Campaign) Interface/Control Ethernet Web Server (full control) ftp Server ftp push notification Scriptable Command-line interface Remote firmware upgrade Built in Ntrip Built-in PPP Other serial communications DynDNS Client Storage USB Host (external data storage) Removable CF card Fixed Internal memory size Signals GLONASS GPS L5 GPS L2C Tracking limitations Galileo Limited * - NO remote access - 2 GB Max CF Only Future Firmware ne Data Logging Multiple Sessions - 2 Configurable memory buffer Future Firmware High-rate 100 Hz Met Support Binex support TCP Streaming Other Unique Features

25 Trimble NetR8 Total control through advanced web interface. Incorporated many features requested by UNAVCO. Continued competitive tiered community pricing structure. Trimble NetR8 Power Low Power (<5 Watts) Internal Battery/UPS (Campaign) Interface/Control Ethernet Web Server (full control) ftp Server ftp push notification Scriptable Command-line interface Remote firmware upgrade Built in Ntrip Built-in PPP Other serial communications DynDNS Client Storage USB Host (external data storage) Removable CF card Fixed Internal memory size Limited 4 GB Signals GLONASS GPS L5 GPS L2C Tracking limitations 3 Codes/SV (e.g. C1, P2, C5) Galileo Data Logging Multiple Sessions - 8 Configurable memory buffer High-rate 50 Hz* (S/N, PR less) Met Support Binex support (7f-05) TCP Streaming Other Unique Features file push Detailed Constellation Info

26 Trimble NetR8 Total control through advanced web interface. Incorporated many features requested by UNAVCO. Continued competitive tiered community pricing structure. Trimble NetR8 Power Low Power (<5 Watts) Internal Battery/UPS (Campaign) Interface/Control Ethernet Web Server (full control) ftp Server ftp push notification Scriptable Command-line interface Remote firmware upgrade Built in Ntrip Built-in PPP Other serial communications DynDNS Client Storage USB Host (external data storage) Removable CF card Fixed Internal memory size Limited 4 GB Signals GLONASS GPS L5 GPS L2C Tracking limitations 3 Codes/SV (e.g. C1, P2, C5) Galileo Data Logging Multiple Sessions - 8 Configurable memory buffer High-rate 50 Hz* (S/N, PR less) Met Support Binex support (7f-05) TCP Streaming Other Unique Features file push Detailed Constellation Info

27 New GNSS Receiver Evaluation What s Next Solicit community input on evaluation and purchasing priorities. Online questionnaire Contact me directly Formal Request for Information (RFI) to all GNSS Hardware manufacturers requesting detailed specifications and UNAVCO member pricing. Both present and future products. May request both specific and general information depending on community requirements. Proceed with formal evaluation of specific hardware set(s) Define set of evaluation criteria Data Quality Usability Special Features???

28 New GNSS Receiver Evaluation In the meantime Trimble continues semi-annual community purchases with tiered volume-dependent prices. Topcon continues PBO fixed-price agreement on GB-1000 GNSS receivers under Year 5 terms. Leica ATHENA prices available to all educational and non-profit research organizations. Project-specific RFP s (e.g. GNS New Zealand, USGS) Small-scale purchases: direct inquiries through UNAVCO. Pricing Features UNAVCO member price lists may be forthcoming from Ashtech and Septentrio in the near future. The Devil is in the Details! Learn from recent experiences 13 months and 8 iterations of testing to finalize upcoming NetRS firmware! System complexity makes finding all potential issues and comflicts impossible, must direct efforts efficiently.

29 Development and Testing Conclusions This is a moving target; technology is evolving very quickly Most or all manufacturers will be releasing new hardware in Maybe a good opportunity to get Last-Year s Model discounts. Buy for now and/or the future? Wait (if possible) to gather more information, encourage competition Prioritize requirements as much as possible My recommendation: be ready for GPS L5. There won t be a One size fits all Solution Purchase price is not the only consideration Firmware upgrades Warranty terms User support for general use or special applications Future information: Contact me Subscribe to UNAVCO Online Knowledge Base:

30 Development and Testing Conclusions This is a moving target; technology is evolving very quickly Most or all manufacturers will be releasing new hardware in Maybe a good opportunity to get Last-Year s Model discounts. Buy for now and/or the future? Wait (if possible) to gather more information, encourage competition