Indian RNSS: NavIC and GAGAN – Experiences and Potentials
Dr Anindya BOSE
GNSS Laboratory, Department of Physics
The University of Burdwan, INDIA
Web: http://bugnss.webs.com

GNSS Laboratory Burdwan (GLB)(Lat 23.25450 N, Lon 87.84680 E)• GNSS Laboratory in The Department of Physics, The University of Burdwan is engaged in R&D activities in the filed ofGNSS with focus towards:
1) Exploration of Multi-GNSS environment for use in India
2)Quality enhancement of GNSS solutions3) Development of cost-effective applications and solutions
4) Capacity Building in the Field of GNSS• GNSS data archive and data sharing• Sponsored Projects from Govt of India Agencies, specially ISRO
Source: http://www.multignss.asia/campaign.html• Collaboration with Industry• Member, Multi GNSS Asia (MGA) [http://www.multignss.asia]• Received recognition from European Space Agency (ESA)

http://bugnss.webs.com
2Our Infrastructure

IRNSS-GPS-SBAS(IGS) Receivers

Multi-GNSS Receivers(Javad DELTA G3T, Triumph LS)

Labsat 3: Record and Replay
SystemLeica GR50

GoeS-1M OEM Boards

U blox
Low-cost
Multi GNSS boards(GPS, GLONASS)RTKLIB: An Open Source Package for GNSSSystems Tool Kit
Courtesy: AGI

http://bugnss.webs.com

3Agenda• IRNSS/ NavIC- brief Introduction• Hardware Availability• Solution and Navigation parameters – brief discussion• Visibility and satellite geometry• Experience in Metropolis Environment of India• Advantages in augmenting Multi-GNSS in constrained situations• Potential for atmospheric studies• Experience with GAGAN• Future research

IRNSS/ NavIC- Indian Effort towards a regional independent satnav
An independent regional navigation satellite system being developed by Indian Space Research Organization (ISRO).

Designed to provide accurate position information service to users in India as well as the region extending up to1500 km from its boundary (primary service area).

More details at: http://www.isro.gov.in/irnss-programmeNavIC: Satellites, Launches, Frequencies
SlNo123456789Satellite

Launch Date

IRNSS 1AIRNSS 1BIRNSS 1CIRNSS 1DIRNSS 1E
IRNSS 1FIRNSS 1GIRNSS 1HIRNSS 1I

Jul 01, 2013
Apr 04, 2014
Oct 16, 2014
Mar 28, 2015
Jan 20, 2016
Mar 10, 2016
Apr 28, 2016
Aug 31, 2017
Apr 12, 2018

L5: 1.1764 GHz, 24 MHz bandwidth
S: 2.4292 GHz, 16 MHz

LaunchVehicle
PSLV- C22
PSLV- C24
PSLV- C26
PSLV-C27
PSLV-C31
PSLV-C32
PSLV-C33
PSLV-C39
PSLV-C41

Orbit Type
GSO
GSO
GEO
GSO
GSO
GEO
GEO
GSO

NavIC: Hardware

IRNSS-GPS-SBAS(IGS) Receiver, (ISRO-Accord)
L and S Bands

Javad Multi-GNSS receivers
Future upgradable for NavIC
L5 only

Leica GR50
L5 only

Not Commercially Available

Racelogic Wideband III
Record and Replay System
L5 only

SkytraQ NavIC-GAGAN-GPS
Evaluation Board
L5 only

Trimble Alloy
L5, SColour
CodeMaximum No. ofSatellite

Minimum No. ofSatellite

76757465645453Always 7Always 6Always 4

NavIC: Visibility
Typical visibility at Central and NorthernIndia, 30 deg elevation mask

Typical PDOP variation from Central India

NavIC: Satellite Geometry

NavIC observations using IGS receiver; Burdwan, INDIA, 06 July 2018NavIC observations using Javad GNSS receivers; Burdwan, INDIA,05 July 2018

Javad DELTA G3T, L5 only

Javad Triumph LS, L5 onlyTypical NavIC satellite signal strength variation (GSOs)

NavIC satellite signal strength variation (GEOs)
13/09/2014, UoB, INDIAIRNSS L5

13.09/2014, UoB, INDIAIRNSS SIRNSS: Position Solution Capabilities(Sept, 2016; 3hrs; 03:00-06:00 am IST), IGS Rx(5.56 x 5.56 m)

IRNSS: Solution in hybrid mode with GPS(Sept, 2016; 3hrs; 03:00-06:00 am IST), IGS Rx(1.11 x 1.11 m)Position Solutions: Observations,(JAVAD DELTA Rx), 2hrs, 29/11/16

NavIC: Experience in Metropolis Environment of India

Pick up vehicle with external GNSS antenna The vehicle is taken through various road conditions at an average speed of 15-20 km/ hr.
 Case- I : In wide highway below or parallel to the flyover.
 Case- II : The narrow road in densely populated area.
17

Case I: (Below Flyover)

Map of study area : EM bypass,Variation
Kolkata of total number of usable satellites (GPS+IRNSS) and PDOP, 25 th
Picture taken from the back of(Direction of vehicle movement is shown in dark line)
Octoberthe 2017
vehicle, below flyover
Image courtesy: Google map• Beneath the flyover, number of visible satellite is less then 4.
• Number of used satellite comes to zeroNo Position Solution.
• Variation
Satellite
Geometryis undefined.
of numberof tracked GNSS
satellites, 25 th October, 201718

Case I: (Beside the Flyover)• Beside the flyover number of visible
satellite is 8 or 9.
• Number of used satellite is 5 or 6.
• Satellite Geometry is poor

Picture taken from the back of the vehicle,
Map of study area
Variation of number of visible GNSS satellites
beside the flyover(Direction of vehicle movement is shown in dark line)
Image courtesy: Google map

Variation of total number of usable satellites (GPS+IRNSS) and PDOP,25th October 201719

Case II: Densely populated dwellingareas with narrow roads
Discussion• Number of total tracked satellite is 4 to 8 in
A, B, C and D regions.
• Number of used satellites sometimes
comesdown to Zero in the aforesaid
regions..
taken from the back of the vehicle, narrow roads
Map of study area, Jadavpur,PictureKolkata
Variation of total number of usablewith buildings alongside
Image courtesy: Google Map
GNSS satellites observed from Jadavpur
area, Kolkata, India on 25th October
2017

Variation of number of tracked GNSS satellites in GPS+ IRNSS operation, Kolkata, India on 25 th October
201720NavIC: Advantages in augmenting Multi-GNSS

March, 2018, Burdwan, INDIA“No GNSS above 60 degree elevation for part of the day”(a), (b) GPS only (2015, 2016);(c), (d) GPS+GLONASS+GALILEO (2016, 2017)

Problem contour over India
Below the dark line problemexists

GPS+IRNSS; 28 April, 2016

Typical NavIC coverage over the Indian region

WE tried to see how NavIC can handle the situation andwhat are the real-time effects ?

NavIC: Advantages inaugmenting Multi-GNSSDynamic Survey in city
environment

Kolkata, INDIA, October 2017
Affected TimeFor many epochs solution is possible using NavIC

Burdwan, INDIA, March 2018
During the affected Time

More solution is obtained in GPS+NavIC operation (left) thanGPS only operation (right) during the affected time

NavIC: Advantages in augmenting MultiGNSS
Static Survey in city environment
(a)

(b)

(c)

(d)
Fig. 17. Static survey of GPS and GPS-IRNSS hybrid operation within constrained city environment during ‘noGPS above 60o’ condition at Burdwan (10 March 2018, Case III). (a) picture of the survey location, (b) and (c)representative skyplots of the GPS and GPS-IRNSS hybrid operation respectively, (d) scatter plot of solutions

Static survey of GPS and GPS-IRNSS hybrid operation withinconstrained city environment during ‘no GPS above 60 deg’condition at Burdwan (10 March 2018, (a) survey location, (b)and (c) representative skyplots (d) solution scatter plot

Comparison of static GPS and GPS-IRNSS hybrid solutions in constrained city
environment of Burdwan during the affected time of GPS visibility
Maximum Variation
TotalTotal(m)Mode Number Solution
2DRMS CEP
SEP MRSE(Time, of Epoch Obtained(m)(m)(m)(m)
IST) (Average (SolutionLatLonAltPDOP)
Success)
GPS468224(18:52 6.28 15.76 50.06
8.28
2.91 8.80 12.85(5.08)(46.09%)19:00)
GPS+
IRNSS
557
557
6.98
4.98 34.81
3.51
1.50 3.83 5.30
(19:02 - (4.30)(100%)
19:11)NavIC: Advantages in augmenting Multi-GNSS
Dynamic Survey in mixed environment; Burdwan University Campus, May-June 2018, IGS Receiver(NavIC 1I used for solution)
GPS only operationDate(Rx used)

Solution capabilities of GNSS combinations in semi-urban mixed environment
Duration of data
Total Epochs
GNSS constellation(s)Solution Tracked Satellite
collection (IST)
usedSuccess
range
Rate

18:43:02 – 18:52:47
587
18:54:33 – 19:04:02
570$NavIC 1I is included in the tracked and used satellites.

1 June 2018

GPS+NavIC operation

GPSGPS+NavIC

45.99%
58.07%

Used Satellite
range

PDOP
range

$1-7

$4-7$2-15$5-12

2.64-16.3
2.64-12.2

NavIC: for Atmospheric Studies

Variation of C/N0 values of IRNSS/ NavIC satellites (LBand) for 30 September, 2016 throughsimultaneous observation from Panhala, WestrenIndia (16.48o N, 74.6o E) and Burdwan, Eastern India(23.15o N, 87.5o E).. The darker thick line is forBurdwan and the thin line is for Panhala• Fixed or low variation of IPP for RF Signal to study the local effects in comparison to other GNSS
• Signal from GEO/ GSO• Extra S-Band for study

Experiences with GAGAN
Position solution results obtained using standalone IRNSS and IRNSS with GAGAN enabled

Constellation Used
IR-S1
IR-L5
IR-L5+SB
IR-S1+SB

Latitude (m)Longitude (m)Altitude (m)P-P[2]

σP-PσP-P

2.5
1.3
0.49

10.5
8.77
2.87

0.55
0.81
0.51

3.49
4.29
2.59

1.9
1.8
1.4

9.88
7.65
6.49

4.3
3.8
3.4

1.0

6.68

0.45

2.86

1.4

9.09

4.2

No. ofSamples

σ[1]

4604
7580
4173
5050

PDOP

Position solution accuracy analysis using IRNSS, GPS with GAGAN enabled
Constellation Used

No ofSamples

P-P
2.3
3.4

Longitude
(m)
σP-P
0.49
2.4
0.34
2.0

Latitude (m)Altitude(m)PDOP

GPL1GPL1+IRL5

2887
7648

σ
0.52
0.68

σ
1.55
1.77

P-P
7.7
12.0

1.91.3

GPL1+IRS1
GPL1+SB9049
6942

0.62
0.47

6.7
2.8

0.82
0.72

3.7
4.0

1.65
1.03

13.2
7.2

1.4
1.6

GPL1+IRL5+SB

6272

0.49

2.8

0.59

2.9

0.738

4.7

1.6

GPL1+IRS1+SB6484

0.31

2.0

0.36

2.0.577

4.8

1.2[1] σ indicates standard deviation of the observations. [2] P-P indicates the peak to peak (maximum) variationand of observations.

Research Roadmap
••••
•
•

Studies using different NavIC-enabled GNSS receivers
Exploring potentials of S-Band Signal
Studies in forest environments
Studies of capabilities of low-cost NavIC receivers
Integration with RTKLib for post processing
Timing capabilities of NavIC• Collaboration, Idea exchangeInternational Groups working with NavIC• Curtin University, Australia• FGI, Finland• University of Calgary, Canada

THANK YOU
http://bugnss.webs.com/

SomnathPratibha

Atanu

SukbyaAcknowledgement: Space Application Centre (SAC), ISRO Ahmedabad, Govt of India
 DRDO, New Delhi, Govt of India
 AICTE, New Delhi, Govt of India My group members

DebipriyaRaisa