facility what’s next? - unavco · facility evaluation process • unavco re-establishing...

Facility

What’s Next? GNSS Modernization and Next Generation Hardware

for the UNAVCO Community

Frederick Blume UNAVCO Science Workshop, 9 March, 2010

Development and Testing

Facility 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).

Facility Evaluation Process

•  UNAVCO Re-establishing Development and Testing Effort –  Manager appointed 2009 (50% FTE) –  D&T Engineer to be hired Q1 2010

•  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

•  Non-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.

Facility GPS Signal Evolution

•  L2C: Civilian code on L2 carrier broadcast by 8 Block IIR-M SV’s since 2005. (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

Facility 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 http://www.geopp.de/media/docs/pdf/geopp_phase_shift_l2c.pdf

•  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 –  No effect on position seen in PBO time series or limited short-baseline

processing.

Facility GPS Signal Evolution – L5

•  L5 Improves signal structure for enhanced performance –  Third Frequency 1,176.45 MHz (25.5 cm; L1=19 cm, L2 = 24.4 cm)

•  Higher power (-154.9 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 TRM29659.00 to TRM59800.80

L1 L2 L5 Gal L2 Glo L1 SBAS

Facility 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!

Facility GNSS Modernization – The Constellations

GNSS (Global Navigation Satellite Systems) Constellations

GPS: USA, 21 + 3 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, 21 + 3 SVs, 17 orbits every 8 sidereal days, FDMA 18 fully operational + 1 L1-only + 2 in maintenance mode 6 more launches scheduled 2010.

Galileo: ESA, 27 + 3 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)

Facility GLONASS

•  GLONASS Available Now – 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.

•  No SV clock corrections… –  Software from NGS under development –  Track (high-rate) Support under development –  Real-time receiver corrections are useful

Facility GLONASS

•  You should use GLONASS if:

Facility GLONASS

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

Facility

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

GLONASS

Facility

Optimistic Deployment Timeline (1-4 year delays?)

GNSS Modernization

Facility

What we’re used to: 1980-2003

GNSS Modernization

Facility GNSS Modernization

Where we’re heading: ~2015


•  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).


•  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.

Facility 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


•  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…


Trimble NetRS Trimble NetR8 Topcon Net-G3A Ashtech ProFlex CORS Leica GRX1200+ Septentrio

PolaRx3eG PRO

Power Low Power (<5 Watts) Yes Yes Yes Yes Yes Yes Internal Battery/UPS (Campaign) No Yes Yes Yes Yes No

Interface/Control Ethernet Yes Yes Yes Yes Yes Yes Web Server (full control) Yes Yes Limited Yes Yes Future Firmware/Current GUI ftp Server Yes Yes Yes Yes Yes No ftp push No Yes No Yes Yes No email notification No Yes No No Yes No Scriptable Command-line interface Yes Limited Yes Yes No Yes Remote firmware upgrade Yes Yes Yes Yes Yes No Built in Ntrip No Yes Yes Yes Yes No Built-in PPP Yes Yes Yes No No No Other serial communications Limited No Yes Yes Yes Yes DynDNS Client No Yes No No Yes No

Storage USB Host (external data storage) No No Yes* - NO remote access Yes No No Removable CF card No No Yes - 2 GB Max No Yes - 1 GB Max No Fixed Internal memory size 1 GB 4 GB CF Only 128 MB 256 MB 2 GB

Signals GLONASS No Yes Yes Yes Yes Yes GPS L5 No Yes Future Firmware No Yes Yes GPS L2C Yes Yes Yes Yes Yes Yes Tracking limitations None 3 Codes/SV (e.g. C1, P2, C5) None L2-P OR L2C (Not both) None L2C OR L5, not both

Galileo No No Yes No Yes Yes

Data Logging Multiple Sessions Yes - 8 Yes - 8 Yes - 2 Yes - 2 Yes - 2 No Configurable memory buffer Yes Yes Future Firmware Future Firmware Yes 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 Yes Yes Yes Yes Yes No Binex support Yes (7f-03) Yes (7f-05) No No Yes (7f-05) No TCP Streaming Yes Yes Yes Yes Yes Yes

Other Unique Features email file push Internal GSM Modem Spectrum Analyzer Detailed Constellation Info Anti-Interference Filter

Upgradeable GNSS Board

Receiver Comparison – Trimble NetRS Baseline

Facility 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) Yes Internal Battery/UPS (Campaign) Yes

Interface/Control Ethernet Yes Web Server (full control) Yes ftp Server Yes ftp push Yes email notification No Scriptable Command-line interface Yes Remote firmware upgrade Yes Built in Ntrip Yes Built-in PPP No Other serial communications Yes DynDNS Client No

Storage USB Host (external data storage) Yes Removable CF card No Fixed Internal memory size 128 MB

Signals GLONASS Yes GPS L5 No GPS L2C Yes Tracking limitations L2-P OR L2C (Not both)

Galileo No

Data Logging Multiple Sessions Yes - 2 Configurable memory buffer Future Firmware High-rate 20 Hz Met Support Yes Binex support No TCP Streaming Yes

Other Unique Features Internal GSM Modem

Facility Leica GRX1200+

•  Advanced web interface •  Binex capability and multiple ring buffers •  ATHENA Pricing Program for Educational and non-profit organizations

Leica GRX1200+


Interface/Control Ethernet Yes Web Server (full control) Yes ftp Server Yes ftp push Yes email notification Yes Scriptable Command-line interface No Remote firmware upgrade Yes Built in Ntrip Yes Built-in PPP No Other serial communications Yes DynDNS Client Yes

Storage USB Host (external data storage) No Removable CF card Yes - 1 GB Max Fixed Internal memory size 256 MB

Signals GLONASS Yes GPS L5 Yes GPS L2C Yes Tracking limitations None

Galileo Yes

Data Logging Multiple Sessions Yes - 2 Configurable memory buffer Yes High-rate 20 Hz Met Support Yes Binex support Yes (7f-05) TCP Streaming Yes

Facility 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.

-35dB

Septentrio PolaRx3eG PRO

Power Low Power (<5 Watts) Yes Internal Battery/UPS (Campaign) No

Interface/Control Ethernet Yes Web Server (full control) Future Firmware/Current GUI ftp Server No ftp push No email notification No Scriptable Command-line interface Yes Remote firmware upgrade No Built in Ntrip No Built-in PPP No Other serial communications Yes DynDNS Client No

Storage USB Host (external data storage) No Removable CF card No Fixed Internal memory size 2 GB

Signals GLONASS Yes GPS L5 Yes GPS L2C Yes Tracking limitations L2C OR L5, not both

Galileo Yes

Data Logging Multiple Sessions No Configurable memory buffer Future Firmware High-rate 20 Hz Met Support No Binex support No TCP Streaming Yes

Other Unique Features Spectrum Analyzer Anti-Interference Filter

Upgradeable GNSS Board

Facility Topcon Net-G3A

•  Highly configurable with GRIL command-line language •  USB Host with unlimited storage capacity •  Future-proof constellation capability

Topcon Net-G3A


Interface/Control Ethernet Yes Web Server (full control) Limited ftp Server Yes ftp push No email notification No Scriptable Command-line interface Yes Remote firmware upgrade Yes Built in Ntrip Yes Built-in PPP Yes Other serial communications Yes DynDNS Client No

Storage USB Host (external data storage) Yes* - NO remote access Removable CF card Yes - 2 GB Max Fixed Internal memory size CF Only

Signals GLONASS Yes GPS L5 Future Firmware GPS L2C Yes Tracking limitations None

Galileo Yes

Data Logging Multiple Sessions Yes - 2 Configurable memory buffer Future Firmware High-rate 100 Hz Met Support Yes Binex support No TCP Streaming Yes

Other Unique Features

Facility Trimble NetR8

•  Total control through advanced web interface. •  Incorporated many features requested by UNAVCO. •  Continued competitive tiered community pricing structure.

Trimble NetR8


Interface/Control Ethernet Yes Web Server (full control) Yes ftp Server Yes ftp push Yes email notification Yes Scriptable Command-line interface Limited Remote firmware upgrade Yes Built in Ntrip Yes Built-in PPP Yes Other serial communications No DynDNS Client Yes

Storage USB Host (external data storage) No Removable CF card No Fixed Internal memory size 4 GB

Signals GLONASS Yes GPS L5 Yes GPS L2C Yes Tracking limitations 3 Codes/SV (e.g. C1, P2, C5)

Galileo No

Data Logging Multiple Sessions Yes - 8 Configurable memory buffer Yes High-rate 50 Hz* (S/N, PR less) Met Support Yes Binex support Yes (7f-05) TCP Streaming Yes

Other Unique Features email file push Detailed Constellation Info

Facility 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 –  ???

Facility 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.

Facility Development and Testing

•  Conclusions –  This is a moving target; technology is evolving very quickly

•  Most or all manufacturers will be releasing new hardware in 2010. •  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: http://facility.unavco.org/kb/

Facility Development and Testing

•  Conclusions –  This is a moving target; technology is evolving very quickly

•  Most or all manufacturers will be releasing new hardware in 2010. •  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

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