Why test glonass?

Why test GLONASS?

• Why test GLONASS?

• What do we want to test?

• Who is involved in the testing?

• Issues with GLONASS

• Planning for testing

• Issues with testing

Evaluate when Oregon DOT surveyors should or should not use GLONASS

• Evaluate when Oregon DOT surveyors should or should not use GLONASS
• Should we add GLONASS capability to the Oregon Real-time GPS Network?
• Benefit to surveyors to know more about the solutions they are using.
• Varying manufacturer claims
• Lots of anecdotal claims and “back-of-the-envelope” tests out there

Testing Productivity

• Testing Productivity

• Does it always help to add GLONASS?
• Will GLONASS always enable a solution in heavy canopy when GPS-only won’t yield a solution?

Testing Accuracy

• Testing Accuracy

• Is accuracy the same, worse, or better than GPS-only in open and closed canopy.
• Some older papers suggest GLONASS degrades accuracy of GPS-only solutions
• But remember the GLONASS constellation was down to 6 or 7 satellites a few years ago.
• One manufacturer currently claims “GPS and GLONASS can increase performance AND accuracy by up to 30% relative to GPS only”.
• Is the accuracy increase the same in and out of canopy?
• Other papers report little accuracy difference when adding GLONASS to GPS-only.

Geometronics Unit, Oregon DOT

• Geometronics Unit, Oregon DOT
• Operating the Oregon Real-time GPS Network

• Oregon State University

• Dan Gillins, Assistant Professor, PhD, PLS
• Submitted abstract to ION for GNSS+ 2014 Conference
• Michael Eddy: graduate thesis
• Processing long static baselines w/ and w/o GLONASS

• You ??

• Any white papers, statistically valid tests, etc. would be appreciated.

Time tags and receiver clock offsets: GPS time vs GLONASS time

• Time tags and receiver clock offsets: GPS time vs GLONASS time
• Reference datum offsets from GPS
• (WGS84) to GLONASS (PZ-90.02)
• GLONASS FDMA format vs the CDMA format for GPS and Galileo
• New Russian K satellites are CDMA
• Different manufacturers have different, usually proprietary, solutions for handling these biases

Very limited GLONASS tracking/monitoring network worldwide; mostly within Russia

• Very limited GLONASS tracking/monitoring network worldwide; mostly within Russia
• Russia plans to add world wide tracking stations
• Current political situation could inhibit GPS/Galileo cooperation with GLONASS

• No GLONASS plan for new signal in L5 Band

• L5 is a Safey-of-Life protected frequency
• L5 is supported by GPS, Galileo and Beidou

“4. Является ли важным с точки зрения конкурентоспособности, чтобы КА системы ГЛОНАСС, в дополнение к запланированным новым кодовым сигналам в традиционных диапазонах ГЛОНАСС (L1, L2, L3) передавали бы еще и сигнал в диапазоне L5? Почему? Если да, то для каких потребителей это важно?”

• “4. Является ли важным с точки зрения конкурентоспособности, чтобы КА системы ГЛОНАСС, в дополнение к запланированным новым кодовым сигналам в традиционных диапазонах ГЛОНАСС (L1, L2, L3) передавали бы еще и сигнал в диапазоне L5? Почему? Если да, то для каких потребителей это важно?”

“4. Is it important in terms of competitiveness, for the GLONASS satellites, in addition to the planned new code signals in the traditional GLONASS bands (L1, L2, L3) to add another signal in the range L5? Why? If yes, for which consumers is this important?”

• “4. Is it important in terms of competitiveness, for the GLONASS satellites, in addition to the planned new code signals in the traditional GLONASS bands (L1, L2, L3) to add another signal in the range L5? Why? If yes, for which consumers is this important?”

• Availability of real-time precise ephemerides for GLONASS?

The Multi-GNSS Experiment (MGEX) has been set-up by the International GNSS Service (IGS) to track, collate and analyze all available GNSS signals. This includes signals from the BeiDou, Galileo and QZSS systems, as well as from modernized GPS and GLONASS satellites and any space-based augmentation system (SBAS) of interest.

• The Multi-GNSS Experiment (MGEX) has been set-up by the International GNSS Service (IGS) to track, collate and analyze all available GNSS signals. This includes signals from the BeiDou, Galileo and QZSS systems, as well as from modernized GPS and GLONASS satellites and any space-based augmentation system (SBAS) of interest.

• Analysis centers will attempt to estimate inter-system calibration biases, compare equipment performance and further develop processing software capable of handling multiple GNSS observation data.

• The development of multi-GNSS IGS products.

Letters to manufacturers

• Letters to manufacturers

• How do their products use GLONASS in RTK and postprocessing.
• Supplemental to GPS or equal to GPS

• Investigate prior research

• White papers
• ION GNSS presentation archives
• E-mail: Dan Gillins, OSU, to Dr Neil Weston, Deputy Director, NGS

NGS has not done too much with respect to GPS +GLONASS processing

• NGS has not done too much with respect to GPS +GLONASS processing
• NGS has spent a few months looking at the Pages software (NGS) to see how GLONASS can be incorporated
• NGS hopes to add GLONASS (to their products such as OPUS) and also focus on Galileo
• With respect to helping out with a study, NGS cannot offer too much other than CORS data with GPS+GLONASS.  
• Do you have more specific ideas in mind?

NGS testing and evaluation of GLONASS would help real-time network administrators and also surveyors in general

• NGS testing and evaluation of GLONASS would help real-time network administrators and also surveyors in general

Perform enough test repetitions to yield statistically valid results.

• Perform enough test repetitions to yield statistically valid results.

• Publish accuracy analysis at the 95% confidence level per FGDC Geospatial Positioning Accuracy Standards.

• http://www.fgdc.gov/standards/projects/FGDC-standards-projects/accuracy/   

Testing in open, medium, and heavy canopy.

• Testing in open, medium, and heavy canopy.
• Establish accurate test networks in canopy with total station network tied to accurate static GPS sites in open canopy.

Testing can’t cover all brands of GPS receivers

• Testing can’t cover all brands of GPS receivers

• Different GPS RTN softwares handle GLONASS differently

• As GNSS constellations change, ongoing testing will be needed

• GPS new CNAV Signals, ie. L5 stronger signal strength is supposed to help in canopy.
• GLONASS: CDMA?, L5?, worldwide tracking/monitoring?
• BEIDOU: coming on strong?
• Galileo: just around the corner?

• Manufacturers will adopt new and better processing algorithms to better take advantage of various GNSS

• All these changes will point out the need for ongoing testing.

• Test networks with accurately positioned marks will continue to be valuable.