GNSS Technology Update

Transcription

1 GNSS Technology Update Speaker: Eric Gakstatter Contributing Editor GPS World Editor - Geospatial Solutions Presented at: Association of Petroleum Surveying & Geomatics Houston, TX April 7, 2015

2 Agenda - GNSS Infrastructure advancements - Sources of GNSS corrections - Space Weather - Trends

3 GNSS is the new GPS GNSS = Global Navigation Satellite System

4 GNSS technology is going to advance significantly more in the next 5 years than it has in the past 10 years

5 GNSS Infrastructure ACTIVE GNSS: -GPS (USA) -GLONASS (Russia) -SBAS: WAAS (North America), MSAS (Japan) EGNOS (Europe), GAGAN (India), Omnistar, RTX, Terrastar, Starfire, Starfix PLANNED GNSS: -Galileo (Europe) -BDS Global (China) -SBAS: SDCM (Russia) -QZSS Regional (Japan) -BDS Regional (China)

6 Augmentation Regional: -RTK Networks/Clusters (Public and Commercial) -Public SBAS (WAAS, etc.) -Commercial SBAS (Omnistar, RTX, Terrastar) -DGPS Global: -Commercial SBAS (Omnistar, RTX, Terrastar, Starfire, etc.) -Public PPP (RT GPS)

7 GNSS is Changing Not only is GNSS receiver technology constantly evolving, so is the GNSS infrastructure (satellites, signals and control). This is one of the reasons that the GNSS industry is so dynamic and will be for the foreseeable future. These changes will affect the way that GNSS mapping and surveying users perform their work. Better, faster, cheaper.

8 GPS Constellation Status

9 GPS Constellation Four GPS launches scheduled in FY2015. The most in one year in a long time. Oct. 2014, Mar 2015, June 2015, Oct 2015 After that, one more II-F model left to launch. Model IIF = L1 C/A, L1/L2 P(Y), L2C, L5 Then, it s time for GPS III satellites. Model III = L1C, L1 C/A, L1/L2 P(Y), L2C, L5

10 There are currently 31 operational GPS satellites. 15 x GPS Block IIA/IIR. L1 C/A, L1/L2 P(Y) 7 x GPS Block IIR-M. L1 C/A, L1/L2 P(Y), L2C 9 x GPS Block II-F. L1 C/A, L1/L2 P(Y), L2C, L5 L2C = More robust iono correction for high precision positioning. No need for crosscorrelation (semi-codeless). L5 = Similar to L2C, but stronger 1176 Civil signals (black, red), Military signals (blue)

11 GLONASS Russia s Satellite Navigation System

12 Declared fully operational in December ~24 operational satellites. Most since A valuable augmentation to GPS. Not used as a stand-alone system. Valuable to high-precision users (RTK, submeter) because it increases productivity. Adds ~6-10 more satellites. Increases productivity, not necessarily accuracy.

13 Transitioning to CDMA radio design on satellites. Glonass-K launched Dec Up to 9 Glonass-M satellites to launch 2015/2016. Ultimate constellation expansion to 30 satellites. Transitioning to PZ geodetic system. Aligned with ITRF at the mm-level.

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15 Copyright 2014 Galileo Europe s Satellite Navigation System

16 First four operational Galileo satellites are test sats converted to operational sats (4). 1 st production launch last Fall. Limited success. A pair injected into the wrong orbit (6). 3/27/15 production launch pair successful (8). Two more launches scheduled this year (12). Constellation of 18 operational Galileo satellites projected in Highly compatible with GPS L1/L5. No L2.

17 BDS (Beidou) China s Satellite Navigation System

18 More high-precision GNSS receivers are sold in China than the rest of the world combined. BDS is currently a regional system of satellites orbiting in a figure eight pattern above China that add ~14 satellites in addition to GPS and GLONASS. The RTK environment in China is better than any other place in the world due to the significant number of satellites in view.

19 China plans to offer a 30-satellite constellation by 2020, some speculate they ll have it complete by Most recent launch was last week (March 30). The launch is believed to be the first Beidou-3 M1 satellite and the beginning of Beidou s Phase III program, which is a 30-satellite global constellation.

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22 GPS+Galileo = 20 average satellites in view. Add 30 more from BDS and 24 from GLONASS satellites in view using 4 constellations.

23 SBAS Satellite-Based Augmentation System

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25 Public SBAS (sub-meter) SBAS WAAS/EGNOS/MSAS/GAGAN. Free source of GPS L1 corrections. SBAS was designed for aviation, but used widely by geospatial professionals as an accurate source of GPS L1 corrections. SBAS was designed primarily for integrity, but can be optimized for accuracy to achieve submeter precision.

26 Commercial PPP SBAS (decimeter world-wide subscription services): - RTX, Omnistar - Starfire - Terrastar PPP SBAS (decimeter) Public PPP SBAS (free decimeter world-wide service): IGS RT <rt.igs.org>

27 OmniStar/Starfire/Terrastar

28 Commercial RTK Networks - Surveying equipment dealers - GNSS eq. manufacturers Trimble/Leica/Topcon Commercial RTK Clusters - Agriculture Public RTK Networks - State agencies (eg. Dept of Transportation) Public RTK Clusters RTK - Plate Boundary Observatory (PBO)

29 Leica SmartNet RTK Bases

30 South Plains RTK Cluster 12m acres

31 TxDOT RTK Bases

32 PBO RTK Bases

33 Omnistar ITRF08 current day epoch WAAS ITRF08 current year epoch DOT RTK Networks NAD83/ NGS CORS streaming (discontinued) ITRF PBO RTK bases -??? Commercial RTK Networks (surveying) -??? Localize? Commercial RTK Clusters (ag) WGS-84?? Disparate Geodesy

34 Public RTK Base Stations in the U.S. Two recent examples of using Public RTK bases:

35 Public RTK Base Stations in the U.S. Case #1. Colorado. -Windows Mobile data collector w/at&t SIM card for internet connectivity -~12 mile baseline -Accuracy: 1.9cm horizontal RMS. Adjusted from ITRF to NAD using HTDP

36 Public RTK Base Stations in the U.S. Case #2. California (SF Bay Area) -Samsung Note smartphone (Android) running AutoCAD ~5 mile baseline, 0.75 precision - Accuracy:????

37 Trends Trending towards real-time decimeter (PPP) and centimeter positioning (RTK) Never in history has real-time, high-precision technology been so available and affordable. And we re only just beginning.

38 High-Precision GNSS Technology The Next 5 Years

39 The Next 5 Years Complete hybrid L5 constellation (GPS/Galileo/BDS). Cheaper/more accurate GNSS receivers. Initial deployment of Europe s Galileo and Chinese BDS. Continued proliferation of RTK Networks. Further refinement of PPP real-time services (eg. Trimble RTX, IGS-RT, others).

40 The new GPS L5 signal will result in very lowcost L1/L5 receivers capable of cm-level horizontal/vertical precision. High-precision GPS receivers trending towards commoditization. RTK on your mobile phone by 2020?

41 Three Gotchas GNSS performance around obstructions such as tree canopy, buildings, terrain blockage. Geodesy datums, coordinate velocities. Combining disparate data sets. Communication for real-time GNSS corrections.

42 Velocities

43 The Geodesy Headache Don t know what you have. Simplicity vs. accuracy. Geospatial software operators follow the path of least resistance. Transformation workflows are not simple or understandable. Velocities are a difficult concept for the average geospatial specialist. Mainstream workflows to deal with velocity models are largely non-existent. Velocity models are a work in progress.

44 Geodesy Takeaways The ability to collect high-accuracy geospatial data is cheaper and easier than ever before. Stewards of geospatial data are largely ill-equipped to accurately deal with disparate data sets. Geospatial workflows are largely ill-equipped to accurately deal with disparate data sets. Velocities are a foreign concept to most geospatial data stewards. Velocity models are a work in progress.

45 Comments? Questions?

46 Eric Gakstatter Contact Information: Subscribe to Survey Scene and Geospatial Weekly Newsletters at Subscribe to GPS World Magazine at