19
5 th th AOR W/S on GNSS AOR W/S on GNSS Hanoi, Vietnam Hanoi, Vietnam Dec. 1-3, 2013 Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal Takeyasu Sakai Electronic Navigation Research Institute

5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

Embed Size (px)

Citation preview

Page 1: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

55thth AOR W/S on GNSS AOR W/S on GNSSHanoi, VietnamHanoi, VietnamDec. 1-3, 2013Dec. 1-3, 2013

GPS/GLONASS/QZSS Multi-GNSSAugmentation Trial by L1-SAIF Signal

GPS/GLONASS/QZSS Multi-GNSSAugmentation Trial by L1-SAIF Signal

Takeyasu SakaiElectronic Navigation Research Institute

Takeyasu SakaiElectronic Navigation Research Institute

Page 2: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 22

IntroductionIntroduction• QZSS (Quasi-Zenith Satellite System) programQZSS (Quasi-Zenith Satellite System) program::

– Regional navigation service broadcast from high-elevation angle by a combination Regional navigation service broadcast from high-elevation angle by a combination of three satellites on the inclined geosynchronous (quasi-zenith) orbit;of three satellites on the inclined geosynchronous (quasi-zenith) orbit;

– Broadcast GPS-like supplemental signals on three frequencies and two Broadcast GPS-like supplemental signals on three frequencies and two augmentation signals, augmentation signals, L1-SAIFL1-SAIF and LEX. and LEX.

• L1-SAIF L1-SAIF (Submeter-class Augmentation with Integrity Function) (Submeter-class Augmentation with Integrity Function) signal offers:signal offers:– Submeter accuracy wide-area differential correction service;Submeter accuracy wide-area differential correction service;– Integrity function for safety of mobile users; andIntegrity function for safety of mobile users; and– Ranging function for improving position availability; all on L1 single frequency.Ranging function for improving position availability; all on L1 single frequency.

• ENRI has been developing L1-SAIF signal and experimental facilityENRI has been developing L1-SAIF signal and experimental facility::– Signal design: SBAS-like message stream on L1 C/A code (PRN 183);Signal design: SBAS-like message stream on L1 C/A code (PRN 183);– Possibility of Multi-GNSS augmentationPossibility of Multi-GNSS augmentation: combined use of GPS and other : combined use of GPS and other

constellations would improve the availability of position solutions.constellations would improve the availability of position solutions. Especially where visibility is limited.Especially where visibility is limited. Upgraded L1-SAIF experimental facility and conducted a Multi-GNSS trial.Upgraded L1-SAIF experimental facility and conducted a Multi-GNSS trial.

Page 3: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 33

QZSS ConceptQZSS Concept

• Broadcast signal from high elevation angle;Broadcast signal from high elevation angle;

• Applicable to navigation services for Applicable to navigation services for mountain area and urban canyon;mountain area and urban canyon;

• Augmentation signal from the zenith could Augmentation signal from the zenith could help users to acquire other GPS satellites at help users to acquire other GPS satellites at any time.any time.

• Footprint of QZSS orbit;Footprint of QZSS orbit;• Centered at 135E;Centered at 135E;• Eccentricity 0.075, Inclination 43deg.Eccentricity 0.075, Inclination 43deg.

QZSQZSGPS/GEOGPS/GEO

Page 4: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 44

QZSS L1-SAIF SignalQZSS L1-SAIF Signal• QZSS broadcasts wide-area augmentation signalQZSS broadcasts wide-area augmentation signal::

– Called L1-SAIF (Submeter-class Augmentation with Integrity Function);Called L1-SAIF (Submeter-class Augmentation with Integrity Function);– Augmentation signal for mobile users designed and developed by ENRI.Augmentation signal for mobile users designed and developed by ENRI.

• L1-SAIF signal offersL1-SAIF signal offers::– Wide-area differential correction service for improving position accuracy; Wide-area differential correction service for improving position accuracy;

Target accuracy: 1 meter for horizontal;Target accuracy: 1 meter for horizontal;– Integrity function for safety of mobile users; andIntegrity function for safety of mobile users; and– Ranging function for improving position availability.Ranging function for improving position availability.

• Augmentation to GPS L1C/A based on the SBAS specificationsAugmentation to GPS L1C/A based on the SBAS specifications::– Broadcast on L1 freq. with RHCP; Common antenna and RF front-end;Broadcast on L1 freq. with RHCP; Common antenna and RF front-end;

Modulated by BPSK with C/A code (PRN 183);Modulated by BPSK with C/A code (PRN 183); 250 bps data rate with 1/2 FEC; Message structure is identical with SBAS;250 bps data rate with 1/2 FEC; Message structure is identical with SBAS; Differences from SBAS: PRN, large Doppler, and some additional messages.Differences from SBAS: PRN, large Doppler, and some additional messages.

– Developed easily if one has the experience to develop SBAS-capable receiver;Developed easily if one has the experience to develop SBAS-capable receiver;– Specification of L1-SAIF: See IS-QZSS document (Available at JAXA HP).Specification of L1-SAIF: See IS-QZSS document (Available at JAXA HP).

Page 5: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 55

L1-SAIF Signal FunctionsL1-SAIF Signal Functions

User GPS/L1-SAIFUser GPS/L1-SAIFReceiversReceivers

• Three functions by a single signal: ranging, error Three functions by a single signal: ranging, error correction (Target accuracy: 1m), and integrity;correction (Target accuracy: 1m), and integrity;

• User receivers can receive both GPS and L1-SAIF User receivers can receive both GPS and L1-SAIF signals with a single antenna and RF front-end;signals with a single antenna and RF front-end;

• Message-oriented information transmission: Message-oriented information transmission: Flexible contents.Flexible contents.

SAIFSAIF : : Submeter-class Augmentation with Integrity FunctionSubmeter-class Augmentation with Integrity Function

RangingRangingFunctionFunction

ErrorErrorCorrectionCorrection

IntegrityIntegrityFunctionFunction

QZS satellitesQZS satellites

GPS ConstellationGPS Constellation

Ranging SignalRanging Signal

3 Functions by L1-SAIF3 Functions by L1-SAIF

Page 6: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 66

ENRI L1-SAIF Master StationENRI L1-SAIF Master Station• L1-SAIF Master Station (L1SMS):L1-SAIF Master Station (L1SMS):

– Generates L1-SAIF message stream in realtime and transmits it to QZSS MCS Generates L1-SAIF message stream in realtime and transmits it to QZSS MCS developed by and installed at JAXA;developed by and installed at JAXA;

– Installed at ENRI, Tokyo; 90km from JAXA Tsukuba Space Center;Installed at ENRI, Tokyo; 90km from JAXA Tsukuba Space Center;– Dual frequency GPS measurements at some locations in Japan necessary to Dual frequency GPS measurements at some locations in Japan necessary to

generate L1-SAIF messages are sent from GEONET in realtime.generate L1-SAIF messages are sent from GEONET in realtime.

L1SMSL1SMSGEONETGEONET

QZSQZS

QZSS MCSQZSS MCS

GPSGPSSatellitesSatellites

Measure-Measure-mentsments

L1-SAIFL1-SAIFMessageMessage

GSI ServerGSI Server(Tokyo)(Tokyo)

ENRIENRI(Tokyo)(Tokyo)

JAXA TKSCJAXA TKSC(Tsukuba)(Tsukuba)

L1-S

AIF S

ignal

L1-S

AIF S

ignal

Ranging Signal

Ranging SignalRan

ging

Signal

Rangin

g Signa

l

K-band Uplink

K-band Uplink

Page 7: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 77

L1-SAIF Correction: GPS onlyL1-SAIF Correction: GPS only

• Example of user position error at Site 940058 Example of user position error at Site 940058 (Takayama);(Takayama);

• Realtime operation with MSAS-like 6 Realtime operation with MSAS-like 6 reference stations in Japan;reference stations in Japan;

• Period: 19-23 Jan. 2008 (5 days).Period: 19-23 Jan. 2008 (5 days).

HorizontalHorizontalErrorError

VerticalVerticalErrorError

1.45 m1.45 m 2.92 m2.92 m

6.02 m6.02 m 8.45 m8.45 m

SystemSystem

StandaloneStandaloneGPSGPS

0.29 m0.29 m 0.39 m0.39 m

1.56 m1.56 m 2.57 m2.57 mw/ L1-SAIFw/ L1-SAIF

RMSRMS

MaxMax

RMSRMS

MaxMax

Note: Results shown here were obtained with geodetic-Note: Results shown here were obtained with geodetic-grade antenna and receivers at open sky condition.grade antenna and receivers at open sky condition.

User location User location for this testfor this test

6 reference6 referencestationsstations

L1-SAIF expe- L1-SAIF expe- rimental arearimental areaStandalone GPS

L1-SAIF Augmentation

GPS Only ResultGPS Only Result

Page 8: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 88

Adding GLONASS: MotivationAdding GLONASS: Motivation

• Increase of augmented satellites improves availability of position solution;Increase of augmented satellites improves availability of position solution;• Also possibly reduce protection levels; Improve availability of navigation;Also possibly reduce protection levels; Improve availability of navigation;• Chance of robust position information at mountainous areas and urban canyons.Chance of robust position information at mountainous areas and urban canyons.

QZSQZS

GPS constellationGPS constellation Additional ConstellationAdditional Constellation= GLONASS= GLONASS

AugmentationAugmentation

UsersUsers

Page 9: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 99

GLONASS: Differences from GPSGLONASS: Differences from GPS• FDMA signals:FDMA signals:

– Change carrier frequency settings with regard to ranging sources.Change carrier frequency settings with regard to ranging sources.

• Reference time and coordinates:Reference time and coordinates:– Time: broadcast time offset information by an L1-SAIF message; Avoids increase Time: broadcast time offset information by an L1-SAIF message; Avoids increase

of unknowns in user receivers;of unknowns in user receivers;

– Coordinates: convert PZ-90.02 to WGS-84.Coordinates: convert PZ-90.02 to WGS-84.

• PRN numbers and insufficient capacity of mask pattern:PRN numbers and insufficient capacity of mask pattern:– Assign PRN numbers of 38 to 61 as GLONASS slot numbers of 1 to 24;Assign PRN numbers of 38 to 61 as GLONASS slot numbers of 1 to 24;

– Introduce dynamic PRN mask solution to broadcast augmentation information Introduce dynamic PRN mask solution to broadcast augmentation information supporting more than 51 ranging sources, reflecting the actual visibility.supporting more than 51 ranging sources, reflecting the actual visibility.

• Missing IOD (Issue of Data):Missing IOD (Issue of Data):– IOD is used to identify ephemeris information in order to match ephemerides IOD is used to identify ephemeris information in order to match ephemerides

between L1-SAIF Master Station and users; Currently using IODE for GPS;between L1-SAIF Master Station and users; Currently using IODE for GPS;

– Identify ephemeris information based on the time of broadcast.Identify ephemeris information based on the time of broadcast.

• Satellite position computation: Satellite position computation: based on PVA as described in GLONASS ICD.based on PVA as described in GLONASS ICD.

Page 10: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1010

Upgrade of L1SMSUpgrade of L1SMS• L1-SAIF Master Station (L1SMS):L1-SAIF Master Station (L1SMS):

– Generates the L1-SAIF message stream and transmits it to JAXA MCS.Generates the L1-SAIF message stream and transmits it to JAXA MCS.

• Upgrade for supporting GLONASS and QZSS:Upgrade for supporting GLONASS and QZSS:– Input module: Supports BINEX observables and navigation message records;Input module: Supports BINEX observables and navigation message records;– Implemented GLONASS extension based on SBAS standards;Implemented GLONASS extension based on SBAS standards;– User-domain receiver software (MCRX) is also upgraded to be GLONASS-capable;User-domain receiver software (MCRX) is also upgraded to be GLONASS-capable;– QZSS is also supported as it is taken into account like GPS.QZSS is also supported as it is taken into account like GPS.

L1SMSL1SMSGEONETGEONET

QZSQZS

QZSS MCSQZSS MCS

GPSGPS

Measure-Measure-mentsments

L1-SAIFL1-SAIFMessageMessage

GSIGSI ENRIENRI JAXAJAXA

L1-S

AIF S

ignal

L1-S

AIF S

ignal

L1C/A

L1C/AL2PL2P

L1C

/AL1

C/A

L2P

L2P

K-band

K-band

GLONASSGLONASS

L1SAL1SA

UpgradeUpgrade

L1C/AL1C/A

Page 11: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1111

Configuration of ExperimentConfiguration of Experiment• Japanese GEONET is already providing Japanese GEONET is already providing

GLONASS and QZSS observables in addition GLONASS and QZSS observables in addition to GPS;to GPS;

• Currently about 1,200 stations are Currently about 1,200 stations are GLONASS/QZSS-capable;GLONASS/QZSS-capable;

• Data format: BINEXData format: BINEX

• L1SMS generates L1-SAIF message in L1SMS generates L1-SAIF message in realtime and broadcast it via QZS-1.realtime and broadcast it via QZS-1.

• For our experiment:For our experiment: 6 sites for reference stations;6 sites for reference stations;

Reference Station (a) to (f)Reference Station (a) to (f) 11 sites for evaluation.11 sites for evaluation.

User Station (1) to (11)User Station (1) to (11)• Period: 2013/1/6 01:00 Period: 2013/1/6 01:00

to 2013/1/9 23:00 (94 hours).to 2013/1/9 23:00 (94 hours).

Page 12: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1212

PRN Mask TransitionPRN Mask Transition• PRN Mask indicates which satellites PRN Mask indicates which satellites

are currently augmented;are currently augmented;

• Semi-dynamic PRN mask: GPS and Semi-dynamic PRN mask: GPS and QZSS satellites are always ON in the QZSS satellites are always ON in the masks;masks;

• PRN masks for GLONASS satellites PRN masks for GLONASS satellites are set ON if the satellite are visible are set ON if the satellite are visible and augmented;and augmented;

• Reflecting our implementation, PRN Reflecting our implementation, PRN mask is updated periodically at every mask is updated periodically at every 30 minutes.30 minutes.

• IODP (issue of Data, PRN Mask) IODP (issue of Data, PRN Mask) indicates change of PRN mask.indicates change of PRN mask.

GPSGPS

GLONASSGLONASS

QZSSQZSS

Page 13: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1313

Elevation AngleElevation Angle

• Rising satellites appear at 5-12 deg above the horizon; Latency due to periodical update of PRN mask;Rising satellites appear at 5-12 deg above the horizon; Latency due to periodical update of PRN mask;• However, GPS satellites also have similar latency; Not a major problem because low elevation However, GPS satellites also have similar latency; Not a major problem because low elevation

satellites contribute a little to improve position accuracy.satellites contribute a little to improve position accuracy.

GPSGPS

GLONASSGLONASS

QZSSQZSS

PRN MaskPRN MaskTransitionTransition

5 deg5 deg

@ User (7)@ User (7)

Page 14: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1414

# of Satellites vs. Mask Angle# of Satellites vs. Mask Angle

• Introducing GLONASS satellites increases the number of satellites in roughly 75%;Introducing GLONASS satellites increases the number of satellites in roughly 75%;• QZSS increases a satellite almost all day by only a satellite on the orbit, QZS-1 "Michibiki" QZSS increases a satellite almost all day by only a satellite on the orbit, QZS-1 "Michibiki" • Multi-constellation with QZSS offers 16 satellites at 5 deg and 7.3 satellites even at 40 deg.Multi-constellation with QZSS offers 16 satellites at 5 deg and 7.3 satellites even at 40 deg.

9.8 SVs9.8 SVs

16 SVs16 SVs

7.3 SVs7.3 SVs

@ User (7)@ User (7)

Page 15: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1515

User Position Error: Mask 5degUser Position Error: Mask 5deg

• GPS+GLO+QZS: 0.310m RMS of horizontal error at user location (7);GPS+GLO+QZS: 0.310m RMS of horizontal error at user location (7);• Looks some limited improvement by using multi-constellation.Looks some limited improvement by using multi-constellation.

Page 16: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1616

User Position Error: Mask 30degUser Position Error: Mask 30deg

• GPS+GLO+QZS: 0.335m RMS of horizontal error at user location (7);GPS+GLO+QZS: 0.335m RMS of horizontal error at user location (7);• Multi-constellation offers a good availability even for 30 deg mask.Multi-constellation offers a good availability even for 30 deg mask.

Page 17: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1717

Error vs. User Location: 5 degError vs. User Location: 5 deg

• Expect horizontal accuracy of 0.3 to 0.5m with L1-SAIF augmentation, regardless GLONASS is used or not;Expect horizontal accuracy of 0.3 to 0.5m with L1-SAIF augmentation, regardless GLONASS is used or not;• There is a little dependency upon the latitude of user location possibly due to an effect of ionosphere There is a little dependency upon the latitude of user location possibly due to an effect of ionosphere

activities.activities.

North South

0.421m0.421m0.283m0.283m

Page 18: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1818

Error vs. User Location: 30 degError vs. User Location: 30 deg

• The horizontal accuracy is still within a range between 0.3 and 0.5m for the multi-The horizontal accuracy is still within a range between 0.3 and 0.5m for the multi-constellation configuration;constellation configuration;

• The accuracy degrades to 1 or 2.5m for GPS-only single-constellation configuration.The accuracy degrades to 1 or 2.5m for GPS-only single-constellation configuration.

North South

0.425m0.425m

Page 19: 5 th AOR W/S on GNSS Hanoi, Vietnam Dec. 1-3, 2013 GPS/GLONASS/QZSS Multi-GNSS Augmentation Trial by L1-SAIF Signal GPS/GLONASS/QZSS Multi-GNSS Augmentation

AOR W/S Dec. 2013AOR W/S Dec. 2013 - Slide - Slide 1919

ConclusionConclusion• ENRI has been developing L1-SAIF signalENRI has been developing L1-SAIF signal::

– Signal design: GPS/SBAS-like L1 C/A code (PRN 183);Signal design: GPS/SBAS-like L1 C/A code (PRN 183);– Planned as an augmentation to mobile users.Planned as an augmentation to mobile users.

• GPS/GLONASS/QZSS multi-constellation supportGPS/GLONASS/QZSS multi-constellation support::– L1-SAIF Master Station was upgraded to support GLONASS and QZSS in addition L1-SAIF Master Station was upgraded to support GLONASS and QZSS in addition

to GPS based on the existing SBAS specifications;to GPS based on the existing SBAS specifications;– Conducted an experiment with broadcast of L1-SAIF signal containing augmentation Conducted an experiment with broadcast of L1-SAIF signal containing augmentation

information of GPS, GLONASS, and QZSS;information of GPS, GLONASS, and QZSS;– Using multi-constellation it can be expected to maintain a good position accuracy Using multi-constellation it can be expected to maintain a good position accuracy

even in higher mask angle conditions representing limited visibility conditions.even in higher mask angle conditions representing limited visibility conditions.

• Further Investigations will include:Further Investigations will include:– Dynamic PRN mask driven by almanac information;Dynamic PRN mask driven by almanac information;– Use of GLONASS observables in generation of ionospheric corrections;Use of GLONASS observables in generation of ionospheric corrections;– Considerations of different types of receiver for reference/user stations; andConsiderations of different types of receiver for reference/user stations; and– Extension to Galileo.Extension to Galileo.

For further information, contact to: For further information, contact to: [email protected]@enri.go.jp