1. INTRODUCTION
Spectacular development of space technology and its applications is no longer remaining a vision out of
reach for the common people. Satellite based communication network has linked the entire nation cutting
across the geography, language and the society. Ever since the birth of Department of Space (DOS) in
1972, Indian space programme has achieved unique distinction of crossing several milestones while
developing indigenous technology and providing technological support for socioeconomic benefit for
millions of people of the country.
Soon, the technological advancement of space technology and its applications have proliferated rapidly to
the remote areas including the North Eastern Region of the country. Realizing the need of special attention
in terms of technological support in managing rich natural resources and improving the poor
infrastructure and communication linkages, North Eastern Space Applications Centre (NESAC) was
established as a joint initiative of Department of Space (DOS) and the North Ea stern Council (NEC) and
came into being on 5th of September, 2000. The Centre is all set to augment the developmental process
in the region by providing the advanced space technology support.
NESAC has now moved to its permanent building in October 2008.
The major functions of the centre are :
 To provide operational remote sensing based natural resource information base to assist
activities on development/management of natural resources in the region.
 To provide operational satellite communication applications services for the region
extending implementation of satellite communication based applications in education, health,
disaster management support, and developmental communication in the region.
 To set up a space science and global change resear ch hub by installation of necessary
instrumentation and networking with various academic institutions of the NE region.

2. SATELLITE COMMUNICATION DIVISION
One most important mandate of North Eastern Space Applications Centre (NESAC) is applications of
Satellite Communication (SATCOM) technology to undertake developmental communication programmes
in the North Eastern Region (NER) to assist education, health, social welfare and other development
activities. The SATCOM application programs can addresses the dissemination of quality education- from
primary to University level, provisioning of Medical and Health-care services, enabling of interactive
connectivity among the rural farming communities , tele-communication support during disaster
management etc. To cater this all this ISRO has a number of vibrant SATCOM applications programs like
Telemedicine, Te-education, Village Resource Centre, Communication support in disaster management etc.
NESAC is playing the key role in implementation & utilization of all above applications programs in all the
eight state of NER in collaboration with other central/state government agencies, NGO’s etc.
The available SATCOM facilities at NESAC are as follows:
 State-of-the art studio facility for content generation and broadcasting of developmental
programs
 Village Resource Centre(VRC) expert node for conducting various training program, providing
agromat advisory and data dissemination
 Satellite Interactive Terminal (SIT) under EDUSAT program for educational activities
 Receive Only Terminal (ROT) under national program on Edusat
 ISRONET system for video conferencing and data transfer activities among the centre of
DOS/ISRO
 Transportable WLL-VSAT system for providing audio-video link and data transfer activities for
communication support in Disaster management and various training and awareness program
 Various system under Ka-band propagation experiment program
 Various system under GAP-4 experiment program
 Various system under IRNSS project
The Ongoing SATCOM applications programs are as follows:
1. Telemedicine
Telemedicine today is one of the most vital SATCOM application programmes of ISRO in the country. The
Telemedicine Programme is an innovative process of synergising benefits of Satellite communication and
information technology with Biomedical Engineering and Medical Sciences to deliver the health care
services to the remote, distant and underserved regions of the country . ISRO has made a modest
beginning in telemedicine using satellite communication in the form of a telemedicine pilot project in the
year of 2001, connecting Apollo Hospital at Chennai with the Apollo rural hospital at Arogonda village in
the Chittor district of Andhra Pradesh. Now a number of telemedicine networks are operational all over the
country.

3. For north eastern states a project known as ISRO-NEC telemedicine project has been formulated in July
2004 using satellite communication through Very Small Aperture Terminal (VSAT) to commission 72
telemedicine nodes in all the districts of all the north eastern states including Sikkim. The state wise
breakup of the nos. of telemedicine centre is: Arunachal Pradesh-8, Assam-23, Manipur-9, Mizoram-7,
Meghalaya-9, Nagaland-8, Sikkim-4 and Tripura-4.The major objectives of the project is to connect the
district level hospitals to the specialty/super specialty hospitals of the region as well as outside the region
for better healthcare at minimum cost using modern technology. The major stakeholders of the project
are ISRO, North Eastern Council (NEC) and state governments of the region. NESAC is coordinating the
project from ISRO side in installation & commissioning of the system, training, monitoring, trouble -
shooting etc. Till date a total of 25 telemedicine centres (Table 1) has been commissioned and remaining
47 are in pipeline. Another telemedicine project known as Army Telemedicine Network for NER is also
operational in the north eastern states in collaboration with Indian Army form March 2008. Under this
network a total of 6 telemedicine centre (Table 2)
Telemedicine today is one of the most vital SATCOM application programmes of ISRO in the
country. The Telemedicine Programme is an innovative process of synergising benefits of Satellite
communication and information technology with Biomedical Engineering and Medical Sciences to
deliver the health care services to the remote, distant and underserved regions of the country.
ISRO has made a modest beginning in telemedicine using satellite communication in the form of a

4. telemedicine pilot project in the year of 2001, connecting Apollo Hospital at Chennai with the Apollo
rural hospital at Arogonda village in the Chittor district of Andhra Pradesh. Now a number of
telemedicine networks are operational all over the country.
For north eastern states a project known as ISRO-NEC telemedicine project has been formulated in
July 2004 using satellite communication through Very Small Aperture Terminal (VSAT) to
commission 72 telemedicine nodes in all the districts of all the north eastern states including
Sikkim. The state wise breakup of the nos. of telemedicine centre is: Arunachal Pradesh-8, Assam-
23, Manipur-9, Mizoram-7, Meghalaya-9, Nagaland-8, Sikkim-4 and Tripura-4.The major objectives
of the project is to connect the district level hospitals to the specialty/super specialty hospitals of
the region as well as outside the region for better healthcare at minimum cost using modern
technology. The major stakeholders of the project are ISRO, North Eastern Council (NEC) and state
governments of the region. NESAC is coordinating the project from ISRO side in installation &
commissioning of the system, training, monitoring, trouble -shooting etc. Till date a total of 25
telemedicine centres (Table 1) has been commissioned and remaining 47 are in pipeline. Another
telemedicine project known as Army Telemedicine Network for NER is also operational in the north
eastern states in collaboration with Indian Army form March 2008. Under this network a total of 6
telemedicine centre (Table 2) has been commissioned in various army hospitals in the region.

5. Table 1: List of civilian Telemedicine centre in NER under ISRO-NEC joint Telemedicine
program
State Total nos. of Telemedicine centre
commissioned under ISRO-NEC
joint Telemedicine project
Location
Arunachal
Pradesh
4 (Four)
1. Ram Krishna Mission Hospital,
Itanagar
2. General Hospital, Naharlagun
3. Civil hospital, Passighat
4. Civil Hospital, Tawang
Assam
1. (Seven)
1. Guwahati Medical College &
Hospital, Guwahati
2. Assam Medical College & Hospital,
Dibrugarh
3. Jorhat Medical College & Hospital,
Jorhat
4. Civil Hospital, Tinsukia
5. Civil Hospital, North Lakhimpur
6. Civil Hospital, Golaghat
7. Civil Hospital, Hailakandi
Manipur 1 (One) 1. Regional Institute of Medical
Science (RIMS), Imphal
Meghalaya 4 (Four) 1. North Eastern Indira Gandhi
regional Institute of Health &
Medical Science (NEIGRIHMS),
Shillong
2. Civil Hospital, Shillong
3. Civil Hospital, Jowai
4. Civil Hospital, Tura
Mizoram 4 (Four) 1. Civil Hospital, Aizawl
2 Civil Hospital, Lunglei
3. District Hospital, Saiha
4. Civil Hospital, Champhai
Nagaland 1 (One) 1. Civil Hospital, Mokukchang
Sikkim 1 (One) 1. S.T.N.M. Government Hospital,
Gangtok
Tripura 3 (Three) 1. Sub-Divisional Hospital Dharmanagar
2. Civil Hospital, Kailsahar
3. Sub-Divisional Hospital,
Kamalpur

6. Table 2: List of Telemedicine centre in NER under Indian Army
State Total nos. of Telemedicine centre
commissioned under Indian Army
Telemedicine project
Location
Assam 2 (One) 1. 151 Base Hospital, Basistha ,
Guwahati
2. Military Hospital, Silchar
Manipur 1 (One) 1. Military Hospital, Liemakhong
Meghalaya 1 (One) 1. Military Hospital, Shillong
Nagaland 1 (One) 1. Military Hospital, Dimapur
Tripura 1 (One) 1. Military Hospital, Agartala
2. EDUSAT Utilisation Programme
One important aspect of SATCOM applications in the North Eastern States is the Tele -Education
Project. ISRO has dedicated to the nation one of its satellites solely for the education sector. It is
called the EDUSAT (also GSAT-3) satellite that was launched on September 20, 2004 from the
Satish Dhawan Space Centre, in Sriharikota, Andhra Pradesh by the Geo-Synchronous launch
vehicle GSLV (F01). It is in fact, India's first thematic satellite dedicated exclusively for educational
services.
The EDUSAT was configured to
meet India’s growing demand for
distance education using audio-visual
medium and employing
Direct-to-home type direct
satellite broadcasting with
interactive Class-room
capabilities. The EDUSAT
Utilisation Program was
envisioned in a manner as to
create state-wise SATCOM
networks for the eight North
Eastern states disseminating
quality education programmes for
different levels of the academia.
Based on the hub networking
topology, the NER EDUSAT network has its hub suitably placed somewhere in the state capital with
the remote ends (SITs & ROTs) housed in some identified primary and higher secondary level
schools, colleges.

7. The hub has one Studio facility from where content is to be generated by experts and then
unicasted or multicasted to the targeted recipients. The EDUSAT has multiple regional beams
covering different parts of India - 5 Ku-band transponders with spot beams covering Northern,
Eastern, Southern, Western and the North-eastern regions of the country, one Ku-band transponder
(National beam) with its footprint covering the Indian mainland region and six Ext. C -band
transponders with their footprints covering the entire country. EDUSAT is being implemented in
three phases- pilot, semi-operational and operational
phases.
The Hub-station
Terrestrial hubs are used to link to and from terminals and convey services like virtual classroom.
The standard used is called Digital Video Broadcasting, Return Channel via satellite (DVB -RCS). The
DVB-RCS is a system that allows two-way communication between the Satellite Interactive
Terminals (SITs) installed at customer's sites via the hub. The DVB-RCS system operates as a Star
configuration, thus its central station is called the "Hub." This station implements the forward link
via a conventional DVB-S chain (similar to digital TV broadcasting) while the return link is
implemented using the DVB-RCS standard. The Hub consists of microwave equipment for the
transmission and reception of signals and a control centre for managing network traffic . This station
also hosts interfacing equipment supporting a wide range of terrestrial interfaces. An important Hub
function is to map the traffic of all remote terminals belonging to each user group.
The Teaching end
Also called as the Expert Node, the Teaching End is the place where the contents (subject/topic
wise) are created by experts and delivered in a time-scheduled manner using preinstalled third-party
software. A general configuration of the teaching end is shown below:

8. The Student end
The student end consists of the Receive-only Terminals (ROTs) and the Satellite Interactive
terminals (SITs) also called the Return Channel Satellite Terminals (RCSTs). Students/ targeted
user group can receive the contents transmitted and even interact with the experts at the teaching
end directly (facility available in SITs only) using a preinstalled third-party software.

9. Status of EDUSAT Network in the NER
Already commissioned:
ARUNACHAL PRADESH: 1 Hub & Studio at Rajib Gandhi University, Itanagar& 50 Satellite
Interactive Terminals (SITs) at various schools and educational institutes across the state. The
network is already operational.
TRIPURA: 1 HUB & Studio at SCERT, Agartala& 50 SITs at various schools and educational
institutes across the state. The network is already operational.
MEGHALAYA: 1 HUB & Studio at DERT, Shillong & 50 SITs at various schools and educational
institutes across the state. The network is already operational.
NAGALAND: 1 HUB & Studio at Kohima Science College, Kohima & 50 SITs at various schools and
educational institutes across the state. The network is going to be made operational soon.
MIZORAM: 1 HUB & Studio at SCERT, Aizawl & 50 SITs at various schools and educational
institutes across the state. The network is going to be made operational soon.
ASSAM: 1 HUB & Studio at SIRD extension centre, Kahikuchi, Guwahati and 34 SITs at SIRD
extension centres and DIETs across the state. The network is already operational.
Under commissioning:
SIKKIM: 1 HUB & Studio & 50 SITs across the state.
Planned:
MANIPUR: 1 HUB & Studio & 50 SITs across the state.
3. Village Resource Centre (VRC) program
ISRO has initiated the setting up of the VRC with a view to integrate its capabilities in satellite
communications and satellite based earth observations to disseminate a variety of services emanating
from the space systems and other IT tools to address the changing and critical needs of the rural
community. This project strives to promote a need based single window delivery system for providing
services in the areas of education, health, nutrition, weather, environment, agriculture and livelihoods to
the rural population and to empower them to face the challenges. The VRC is a totally interactive VSAT
(Very Small Aperture Terminal) based network. VRCs will be set up in association with grass root level
organisations, who have a strong field presence and experience of mobilising communities to act for
development and proven track record.
VRCs will provide a variety of services like telemedicine, tele -education, data base on the natural
resources, interactive farmers’ advisories on agriculture, fisheries, wea ther etc. The VRCs will be managed
by the associating agency and it is the capability of the associating agency to make value addition on the
services provided. They can also dovetail their existing rural development programmes to VRC.
The overall implementation of the project will be jointly by ISRO and the associating agency. The
associating agency is expected to set up the required infrastructure and required manpower to manage
the VRCs. ISRO will provide the satellite connectivity for communication, tele-education, telemedicine and
required equipment. The monitoring of the progress of the project and also the quality of the technical
input/output etc will be evaluated time to time and based on this proper corrective measures will be taken
up.
NESAC has coordinated the identification of associating agency, site surveying, installation,
commissioning, training and creation of natural resource database of the target villages using RS & GIS
technology for the VRC network in NER.

10. Status of VRC Network in the NER
Assam
In Assam, a partnership between ISRO and Assam Branch of Indian Tea Association (ABITA) has been
formed to commission VRC network in the rural areas of Assam to uplift the life and livelihood of the
people. ABITA GraminKrishiUnnayanPrakalpa (ABITA-GKUP) is working as the associating agency which
has taken the overall responsibility of operating 10 VRCs in 10 selected village clusters of Assam covering
109 villages and a population of 1, 20, 501. The locations are Lohowal, Moran, Binduguri, Doomdooma,
Paneri, Borgang, Lakhimpur, Margherita, Sonari&Mariani.This network has 3 expert VRCs located at
ABITA-GKUP office, Guwahati; NESAC, Shillong and Assam Agricultural University, Jorhat. This VRC
network was inaugurated by Sri TarunGogoi, Honorable Chief Minister of Assam in the month of
November, 2008.

11. The Centre is equipped with the following communication systems:
 Fixed / Transportable WLL-VSAT System, to provide two-way audio-video link between the
studio and any part of the country.
 INSAT Type C handheld terminals for message transmission, for providing emergency
communication support in a disaster situation.
 SpaceNet connectivity.
 Expanded TDCC studio with standby power supply to take up uninterrupted transmission of
Developmental Communications programmes.
 Satellite Interactive Terminal to monitor Edusat programmes in regional beam
 VRC Expert Node Hardware & software.
 One Automatic Weather Station.
ISRO Geosphere Biosphere Programme (IGBP)
ISRO Geosphere Biosphere Programme is focused to understand the Land-Air-Ocean interactions
through Geosphere-Biosphere-Atmospheric mass and energy exchange processes that contribute
to the overall understanding of parameters responsible for our climate change. The programme
has nine major projects covering distinct and cross cutting subjects. NESAC has been identified as
one of the major centers for conducting some of the studies under this programme. NESAC has,
so far, been contributing in four of the projects as mentioned below:
 Aerosol Radiative Forcing over India
 Atmospheric Boundary Layer Characterization
 Atmospheric Trace Gases Chemistry, Transport and Modeling (AT-CTM)
 National Carbon Project (NCP)

12. Aerosol Radiative Forcing over India (ARFI)
The project is coordinated from Space Physics Laboratory, Thiruvanandapuram. At NESAC the
objective of the programme is to characterize regional aerosol through long term station
measurements and campaigns. Different optical, physical, and Chemical properties of aerosol like,
size distribution, number concentration, optical depth, mass concentration, aerosol type, etc are
measured and used in the models to estimate the radiative forcings of the aerosol. The direct and
indirect effects of aerosol are studied in detail to understand the aerosol-cloud interaction. As NER
is a land locked area cobered by hills all around with the Brahamaputra plains at the centre, the
contribution of long range transport on total regional aerosol load forms large part of the study.
Figure : Diurnal and seasonal variation of aerosol black carbon over Umiam
Figure : Monthly averaged spectral aerosol optical depth
Atmospheric Boundary Layer Characterization
The boundary layer plays a very critical role in modulating the local weather. The data from three
instruments (SODAR, mini boundary layer mast, and PisharotySonde) are used to estimate the
evolution of atmospheric boundary layer. Information on the boundary layer shall be incorporated
in the numerical weather prediction models to improve the accuracy of the models. The
information shall also be used in modeling the dispersion of various trace and green house gases.

13. Instrumentation and infrastructure development
Observation forms the basis of research in Atmospheric and Environmental Science. The
success of ASP and IGBP depends on data from a reliable and adequate set of instruments.
The number of weather observatories in NER was too less to have enough data to conduct
a meaningful study on weather and climate. NESAC with support from ISRO took necessary
steps to reduce the gaps in such observational network. ISRO developed Automatic
Weather Station (AWS) came handy in this initiative. The centre has also procured
instruments to study the physical properties of aerosols and its forcings, planetary
boundary layer, upper atmosphere, etc.
AutomaticWeather Station Network
Eighty AWS have been installed across eight states of NER in collaboration with several
state and central government institutes operating in the region. The AWS records hourly
data on Rainfall, Wind Speed, Wind Direction, Atmospheric Pressure, Relative Humidity,
Temperature and Sun shine duration. The data is stored in a local data logger in addition to
transmitting twice within one hour after collecting the data. The transmitted data is
received at meteorological and oceanographic satellite data archival centre (MOSDAC),
Space Applications Centre, Ahmedabad and put in their web site (http://mosdac.gov .in).
There are 24 AWS in Assam, 16 in Meghalaya, 15 in Arunachal Pradesh, 7 in Nagaland, 6 in
Manipur, 5 in Mizoram, 5 in Tripura, and 2 in Sikkim.
The data from these AWS are being extensively used by Agriculture departments, water
resource departments, etc. of some state governments. Besides, the data forms back bone
of flood forecasting and drought estimates, being carried out by NESAC.

14. Mini Boundary Layer Mast
It provides wind speed, wind direction, temperature and relative humidity at three vertical
levels (at 8m, 8m and 15m). In addition it provides ground level data on rainfall,
atmospheric pressure, net incoming and outgoing radiation, soil moisture (at five levels up to
1 m) and soil temperature (at seven levels up to 1m). It can record data at 1 second interval
and transmits every four minutes average data via SMS using a GSM connection
Sound Detection and Ranging (SODAR)
The data from this instrument is used for studying the boundary layer
dynamics. It provides the wind speed value along the E-W, N-S and
vertical direction and measures the pockets of turbulence within the
atmospheric boundary layer. The instrument provides vertical profile
data up to 1 km (apprx.)
Atmosphere probing using Pisharotysonde
Pisharotysonde along with the ground station hardware were developed by VSSC,
Thiruvanthapuram. One sonde is launched every week using hydrogen gas filled balloon.
The sonde has sensors for measuring ambient temperature, relative humidity, atmospheric
pressure and a GPS receiver and a transmitter. The GPS receiver estimates the
instantaneous position of the balloon which is used to find the wind speed and direction.
The sonde collects and transmits data at one second interval. The balloon normally reaches
to a height of 25 km (apprx) before burst.
Multi Wavelength Radiometer
The instrument was developed by Space Physics Laboratory,
Thiruvanandapuram. It records Aerosol optical depth, columnar water

15. vapor and columnar ozone, by measuring spectral extinction at ten wavelength bands,
centered at 380, 400, 450, 500, 600, 650, 750, 850, 935 and 1025 nm.
Microtops II Sunphotometer
The instrument records Aerosol optical depth, columnar water vapour
and columnar ozone by measuring spectral extinction at five
wavelength bands, centered at 380, 440, 500, 936 and 1020 nm. It
is a light weight and portable instruments, ideal for field
measurements. It has a GPS receiver connected to it to record the
measurement location.
Aethalometer
The instrument provides aerosol black carbon (BC) concentration in ng per m-3 of air
sample at seven different channels (wavelength centered at 370, 470, 520, 590, 660, 880
and 950 nm). Aerosol BC is a very critical particulate pollutant having strong radiation
absorbing characteristics. The spectral measurement of BC helps in understanding the
potential BC sources and their relative impact.
Micro Rain Radar
It is FM-CW (frequency modulated continuous wave) radar operating at 24.1 GHz. It
measures the vertical profile of DSD of rainfall. The profile is measured at 32 range gates
and at every level total rain, rain drop number density (per m-3of air), total precipitable
water etc are measured. The range bin (200 meter at NESAC) and sample interval (30
seconds at NESAC) is user selectable.
The centre is also procuring Electric Low Pressure Impactor, Boundary Layer Lidar (BLL),
and Online analysers for SOx, NOx, CO, CH4,O3 gases.