Update on major activities undertaken by the Department of Space in the year 2020-21
The Department of Space, Government of India has the primary responsibility of promoting the development of space science, technology and applications towards achieving self-reliance and facilitating in all round development of the nation. The report narrates all the major activities of the department including navigation, earth observation and Gaganyaan
Department Of Space (DOS), Government of India has recently released the annual report 2020- 2021. The report updates the major activities undertaken by the department in the year 2020-21. DOS has the primary responsibility of promoting the development of space science, technology and applications towards achieving self-reliance and facilitating in all round development of the nation. The report narrates all the major activities of the department including navigation, earth observation and Gaganyaan. The complete report can be accessed at https:// www.isro.gov.in/2020-2021-english.
Satellite Navigation (SATNAV) is one of the important programmes of the Department. There are two main components of this program.
– Navigation with Indian Constellation (NavIC).
GPS Aided Geo Augmented Navigation (GAGAN)
The GPS Aided Geo Augmented Navigation (GAGAN) system is developed by Indian Space Research Organization (ISRO), together with Airports Authority of India (AAI) to deploy and certify an operational SBASSatellite Based Augmentation System for the Indian Flight Information Region (FIR), with expansion capability to neighboring FIRs. GAGAN provides a civil aeronautical navigation signal consistent with International Civil Aviation Organization (ICAO) Standards and Recommended Practices (SARPs) as established by the GNSS Panel.
The GAGAN is presently operational with three signals in space (PRN 127, PRN 128, PRN 132) from three GEO satellites viz GSAT-8, GSAT-10 and GSAT-15 respectively. According to the annual report, the renewal activities for the allocation of PRN 127 and PRN 128 for a period of 10 years have been completed. GAGAN certification for Navigation Performance level of Approach with Vertical Guidance (APV-1) over India & Required Navigation Performance (RNP 0.1) within Indian Flight Information Regions has been extended for further 24 months with effect from Jul 19, 2020.
Deployment Readiness Test (DRT) of new software was held from Sep 28 to Oct 11, 2020 at Bengaluru and ISRO and DGCA members reviewed the procedures and test results. Technical Review Team (TRT) meeting was held on Nov 05, 2020 to review, provide directions and guidance for GAGAN program.
Navigation with Indian Constellation (NavIC)
NavIC is an independent regional navigation satellite system developed and maintained by India. It is designed to provide accurate Position Velocity and Timing (PVT) information service to users in India as well as the region extending up to 1500 km from its boundary, which is its primary service area (5°S to 50°N and 55°E to 110°E). NavIC is providing two types of services, namely, Standard Positioning Service (SPS) and Restricted Service (RS) and is expected to provide a position accuracy of better than 20m (2σ) over the primary service area and timing accuracy better than 40 ns (2σ). The IRNSS system consists of Ground Segment, Space Segment and User Segment.
(a) Space Segment
The NavIC space segment constellation is configured with seven satellites with three in Geo Synchronous Orbit (GSO) and four in Inclined Geo Synchronous Orbit (IGSO). The constellation has been operational since June 2016. IRNSS-1A and IRNSS- 1G are currently being used for short messaging services. The replacement satellite IRNSS 1I (for IRNSS 1A) was launched on April 2018 and is currently operational. NVS-01 is planned as replacement satellite for IRNSS-1G. NVS-01 is under development and it is planned to be launched in 2021-22. The updated version of IRNSS SPS Interface Control Document (ICD) (version 1.1) has been hosted in ISRO website with information to utilize the services of IRNSS-1I. The Indian Regional Navigation Satellite System (IRNSS) has been accepted as a component of the World-Wide Radio Navigation System (WWRNS) for operation in the Indian Ocean Region by the International Maritime Organization (IMO).
(b) Ground Segment
• The ISRO Navigation Centers (INC) are operational at Byalalu, Bengaluru and Lucknow. INC1 (Byalalu) and INC2 (Lucknow) together provide seamless operations with redundancy.
• IRNSS Network Timing facility (IRNWT-I) is operational at Byalalu, Bengaluru. The IRNWT-II has been established at Lucknow and is operational since February 2018. Both the Timescales at IRNWT-I and II operate with a difference of 20ns (2σ) accuracy with respect to UTC. Two Way Satellite Time and Frequency Transfer (TWSTFT) and Global Navigation Satellite System (GNSS) all-in-view methods are used for time synchronization between INC-1 and INC-2 and with National Physical Laboratory India (NPL-I).
• Sixteen IRNSS Range & Integrity Monitoring Stations (IRIMS) are operational with fifteen of these stations located within the country and one at Mauritius. Additional future IRIM stations establishment at Japan and Russia in progress.
• The IRNSS Data Communication Network (IRDCN) with Terrestrial and Very Small Aperture Terminal (VSAT) links is operational with redundancy among all the ground elements.
• The IRNSS Spacecraft Control Facility (IRSCF), monitors and controls the IRNSS satellites and is operational at Master Control Facility (MCF) Hassan and Bhopal. The IRSCF uplinks the navigation data to the satellites in addition to regular TT&C operations. IRSCF stations at MCF- Hassan and Bhopal work as redundant to each other for IRNSS TTC operations.
• Four IRNSS CDMA Ranging (IRCDR) stations are operational at Hassan, Bhopal, Shillong and Jodhpur. These stations are used for two-way ranging of IRNSS satellites. Two additional IRCDR stations are planned at Trivandrum and Port Blair.
(c) User Segment
ISRO is involved in the development and technology transfer of various types of user receivers. The following types of receiver and receiver technology are being developed.
• FPGA based SPS receiver design and development
• 36 Channel configurable SPS Base Band ASIC based receiver
• G3I NavIC BB Application Specific Integrated Circuit (ASIC) Receiver with Lower Node technology
• Payload Coherency Test Receiver
• Design and development of receivers for new L1 civilian signal.
• Recognition by International Maritime Organisation – As a part of the objective to enable applications of NavIC in maritime field, ISRO submitted documents related to the performance, test results and applications of NavIC to International Maritime Organization (IMO). Through Director General of Shipping (DGS), ISRO attended the meetings of Maritime Safety Committee (MSC) and Sub-Committee on Navigation, Communication and Search and Rescue (NCSR) of IMO. In the 102nd session of the Maritime Safety Committee (MSC- 102) held in November 2020, IMO recognized NavIC as a component of the WWRNS. It stated that NavIC meets the operational requirements to assist in the navigation of ships in ocean waters.
• Incorporation in Radio Technical Commission for Maritime Services (RTCM) standard – RTCM Standard 10403.3 defines the standards for Differential Global Navigation Satellite Systems (DGNSS). NavIC L5 successfully cleared all the tests for incorporation into RTCM standard. The Special Committee (RTCM SC- 104) during its meeting in May 2020 approved NavIC L5 signal to be included in the RTCM standard. The latest release of RTCM 10403.3 Standards Amendment-1 includes NavIC L5. This will enable NavIC application in the differential GNSS catering to maritime, surveying, construction, asset monitoring, deformation monitoring, geodesy, etc.
Incorporation in 3GPP standard – ISRO in co-operation with members of Telecom Standards Development Society of India (TSDSI) has been working towards inclusion of NavIC in 3GPP standards for assisted GNSS in the 4G. In 2019, 3GPP had adopted Work Item for inclusion of NavIC into the 4G standard. As part of the Work item activity, NavIC Receiver Compliance Performance Standards were submitted to 3GPP. During its 110th meeting of RAN-4 held in June 2020, 3GPP approved inclusion of NavIC in Release 16.This step will enable advanced positioning features like indoor positioning, better battery efficiency, fast position fix, etc. with NavIC satellite system.
• NavIC in Mobiles: To enable the use of NavIC in mobile phones, efforts are being channelized with the following stakeholders.
a. Chip Manufacturers: Major mobile chipset manufacturers (Qualcomm, Mediatek) have released mobile processors which are NavIC enabled. These releases have started since January 2020. ▫ Qualcomm – Snapdragon 460, 662,690,720G, 765,865, 888 ▫ Mediatek – Dimensity 800, 1000
• NavIC in low power GNSS chips: ISRO has provided technical support to chip manufacturers like Allystar, Trimble, Quectel, Skytraq, U-Traq, Accord, Broadcom, etc. to enable inclusion of NavIC in their GNSS chips. Due to this, all these manufacturers have support for NavIC L5 signal in their latest chips. This has facilitated usage of NavIC L5 in many civilian applications including vehicle location tracking. However, newer applications like wearable devices, personal trackers, IoT devices, etc. which require small form factor and very low power are generally catered to by single frequency (L1) modules. The wearable devices market in India is anticipated to expand at the rate of ~26% per annum (source: market reports). In order to proliferate NavIC in this sector, all the subsequent satellites will feature L1-band signal in addition to the legacy L5 and S bands. ISRO conducted an interface meeting with all the major chip manufacturers in March 2020 and introduced them to the new L1 signal. ISRO is sharing all the relevant technical details with the chip manufacturers to facilitate inclusion of NavIC L1 into low power GNSS chips at the earliest.
• NavIC Messaging Service:
a. NavIC Messaging Receiver: Indian National Centre for Ocean Information System (INCOIS) is effectively using the NavIC messaging service to broadcast alerts messages such as cyclone, high wave etc. and provide information on Potential Fishing Zone (PFZ) for the fishermen venturing into deep sea. ISRO has become part of an initiative by the National Disaster Management Agency (NDMA) to evolve a Common Alert Protocol (CAP) for major natural disasters like landslides, earthquakes, floods, heavy rains, avalanches, etc. NavIC Messaging System has been recognized as an effective means of disseminating the alert messages and is taken up for phase-1 implementation.
b. Second Generation Distress Alert Transmitter (SG-DAT): ISRO developed Second Generation Distress Alert Transmitter (SG-DAT) by integrating the features of NavIC Messaging Receiver (NMR) and Distress Alert Transmitter (DAT). In this system, fishermen can send a distress alert through the regular DAT link to the rescue centre and the acknowledgement for the reception of distress signal and impending rescue attempt will be sent through the NavIC messaging service. The hub has been established at ISTRAC along with the existing COSPARSARSAT ground system. SG-DAT terminal prototype development is completed and technology has been transferred to six industries through NSIL for commercial deployment.
• NavIC based Timing applications – ISRO and NPL are assisting Department of Consumer Affairs to establish one primary timescale (stratum 0) at Bengaluru and five secondary timescales (stratum 1) at Ahmedabad, Bengaluru, Bhubaneswar, Faridabad and Guwahati. These timescales will be integrated and operate with in-house ISRO’s timescale software suite. The system architecture has been finalised and cleared for procurement. These timescales will provide accurate IST dissemination across India and would ensure national security and enhances cyber security resilience.
• NavIC Performance Evaluation – NavIC performance is evaluated on quarterly basis and the performance evaluation reports are uploaded to the ISRO website on regular basis. Five reference receiver locations are identified in North, South, East, West and Central regions of the country to carry out the detailed performance evaluation. NavIC dual frequency SPS signals are used to check the performance from the user perspective. The achieved position accuracy is better than 10m (2σ). NavIC – GPS (Global Positioning System) – SBAS (Satellite Based Augmentation System) user receivers are being procured by Satellite Navigation Programme (SNP) for performing the NavIC SPS signal performance evaluation in NavIC service area. Presently the acceptance testing of receiver is in progress. These receivers will be deployed across India for remote navigation data collection and performance evaluation
. • Incorporation of NavIC in Interoperable Space Service Volume (SSV) – The Space Service Volume (SSV) provides definition for interoperable GNSS SSV for space users and space receiver manufactures. ISRO is a part of the task team constituted under International Committee on GNSS (ICG) comprising of all GNSS service providers. Analysis and simulation(s) have been carried out for evaluating the availability / signal strength of GNSS satellites for space users. Based on the simulation study, the SSV booklet version-1 has been released by United Nation Office for Outer Space Affair (UNOOSA).
The current NavIC satellite constellation comprises of six operational navigation satellites and two satellites for messaging services. It is planned to realize five navigation satellites viz., NVS- 01/02/03/04/05 as replacement to the satellites in the current constellation. NVS-01 satellite is in developmental stage and it will be placed at IRNSS- 1G. These satellites shall be located at the existing orbital slots and ensure continuity of NavIC services.
NVS-01/02/03/04/05 will be configured with navigation payloads in L5 & S bands and ranging payload in C-band similar to existing IRNSS satellites. Additionally, it is proposed to incorporate a new interoperable civil signal in L1 frequency in the navigation payload. These replacement satellites, with a targeted mission life of minimum 12 years.
EOS-01 was successfully realized and launched onboard PSLV-C49 on Nov 07, 2020. The primary objective of the mission is to provide X band SAR imaging services with improved frequency of observation over area of interest. The satellite has the capability to operate in day, night and allweather conditions and provides imaging data for various applications related to land, water & environment which is required for agriculture, forestry, water resource, flood inundation estimation and disaster management. This is the third satellite in the constellation of three satellites to meet the user requirement. All three satellites in the constellation viz RISAT-2B, RISAT-2BR1 and EOS- 01 are performing to specification and providing satisfactory services to the users.
Gaganyaan – Human Space Flight
Gaganyaan is the first project taken up by HSFC for demonstrating human spaceflight capabilities. It is the maiden manned mission of ISRO which involves development of a host of new technologies and activities that need to be taken up concurrently across all ISRO Centres within the stipulated schedule. The objective of Gaganyaan is to carry a crew of three to Low Earth Orbit (LEO), perform a set of predefined activities in space, and return them safely to a predefined destination on earth.
New systems are required to undertake human spaceflight namely Human rated launch vehicle, Crew Module (CM) system, Service Module (SM) system, Crew Escape System (CES) and Environmental Control and Life Support System (ECLSS). The crew selection and training, development of human centric products, human rating certification system, dealing with man- machine interfaces are other domains of manned space flight that is addressing concurrently.
The human rating of GSLV MKIII has already been initiated at VSSC. The launch complex system at SDSC-SHAR and ground infrastructure are being augmented towards accommodating the crew activities. Communication network including ground based and space-based systems is planned to provide near 100 % coverage during various phases of mission viz., ascent, on-orbit, re-entry and descent. Selection of crew for the first mission has been completed and crew training activities are in progress at Russia in association with Indian Air Force. Plan of action is in place towards realization of human centric products with the assistance of Defence Research and Development Organisation. An Interagency committee for recovery of crew with Indian navy in lead role has been constituted and the committee has initiated the crew recovery related activities.
Many tests are planned to validate launch vehicle technologies. These tests are planned before the launch of first unmanned flight. Such as:
• Test Vehicle Mission for Escape System Qualification
• HS200 static test
• Vikas Engine Hot Test
• CE20 Hot Test
Source: Annual Report 2020-2021, Government of India, Department of Space www.isro.gov.in/2020-2021-english
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