Trends in satellite communications and the role of optical free-space communications
#1

The communication needs of Earth observation satellites is steadily increasing. Within a few
years, the data rate of such satellites will exceed 1 Gbps, the angular resolution of sensors will be
less than 1 μrad, and the memory size of onboard data recorders will be beyond 1 Tbytes.
Compared to radio frequency links, optical communications in space offer various advantages
such as smaller and lighter equipment, higher data rates, limited risk of interference with other
communications systems, and the effective use of frequency resources. This paper describes and
compares the major features of radio and optical frequency communications systems in space and
predicts the needs of future satellite communications.
OCIS codes: 010.0010, 010.1330, 010.3310, 060.4510, 350.6090.
1. Introduction
Images sent from the National Aeronautics and Space Administration’s (NASA) rover Opportunity
indicate the former existence of a salty sea on Mars, which is essential information when investigating the
origin of the planet [1]. Today, images like those from Opportunity, as well as other types of data, are
routinely conveyed in real time to points all over the world. Radio frequencies (RF) are usually used for
such long-distance links in space. However, the recent progress in optics and laser technologies,
especially in fiber optics, is ushering in an era of inter-orbit communications using laser beams. The
European Space Agency (ESA), in its Semiconductor Laser Intersatellite Link Experiment (SILEX), has
routinely used a 50-Mbps optical communication page link twice a day between a low earth orbit (LEO)
satellite and a geostationary earth orbit (GEO) satellite since 2003 [2]. The Optical Inter-orbit
Communications Engineering Test Satellite (OICETS) developed by the Japan Aerospace Exploration
Agency (JAXA) will be launched in summer of 2005 and will feature a laser communication page link with the
SILEX terminal [3]. The SmartSat-1 project of the National Institute of Information and Communications
Technology (NICT) in Japan plans to demonstrate in-orbit verification of a small optical terminal on
board twin satellites in 2007 [4]. NASA, in its Mars Telecommunications Orbiter project, plans to
establish a laser communication page link between Mars and Earth in 2010, which will be able to transmit
information at a data rate of 1~30 Mbps [5].
Both RF and optical waves are electromagnetic waves; however, there are many advantages to using
optical waves in space. These include reduced mass, power, and volume of equipment, higher data rates,
no tariffs and no regulatory restrictions as experienced for RF bands [6]. These assets are a consequence
of the high frequency of optical waves. This paper is organized as follows. The next section describes
trends in satellite communications and the future use of optical communications. The main features of RF
and optical communications systems in a LEO-GEO scenario are discussed in Section 3. Section 4
compares LEO-GEO, LEO-LEO, GEO-GEO, and deep space communication scenarios. Section 5
classifies the RF and optical communications systems based on their beam divergence and data rate.
2. Trends in satellite communications
2.A. Support for manned space activity

Recently, the first private manned spacecraft exceeded an altitude of 100 km twice within a 14 day period
[7]. In the near future, people who have not undergone astronaut training will be able to travel into space
in space planes. High-speed Internet access should therefore be available in a space plane as well. In a
manned space station like the International Space Station (ISS), the leisure available to the astronauts
should reflect that available on the ground. For instance, to relieve stress, popular movies, audio, and
multimedia contents should be available to astronauts in the ISS. A 1-Gbps optical communication link
would enable us to send, e.g., the latest movies to the ISS within one minute. Another, may be more
important aspect for the ISS, is data transmission of the many scientific missions to be performed. They
produce massive scientific experimental data which, in many cases, should be downloaded
instantaneously to a ground station. An optical communication page link is the proper medium for such
infrastructure in space.
2.B. Data transmission from observation satellites
Many Earth observation satellites have been developed for weather forecasting and for probing our
environment. For more accurate measurements, higher resolution will be required from onboard sensors
and the frequency and area of the observations will increase. Figures 1 and 2 show trends in the data rate
and resolution of the sensors for non-military Earth observation satellites. The trends cover optical
sensors and RF synthetic aperture radar (SAR) systems via intersatellite and direct communication links
to ground stations [8]. The data rates seem to drop with passing time for GEO. However, the data relay
satellites and commercial communication satellites are not included in the figure. As recently launched
commercial satellites at GEO have the total transponder bandwidth of about 1 GHz even in GEO, the
communication capacity does not drop [9]. Figures 3 and 4 show the trends in data storage capacity and
the number of bits per pixel of stored image data. For 2010, one can easily make the following
predictions: The data rate of some satellites will increase to several gigabits per second; the angular
resolution of some satellites will be approximately 0.1 μrad, corresponding to a resolution of several ten
centimeters on Earth; the data storage capacity of onboard data recorders will be several terabytes; and
the number of bits per pixel will be larger than 13. The acquired information will drastically increase with
monitoring frequency, observation area and the resolution of the images. Monitoring from satellites will
not only be done for special area but real-time observations of the entire world will take place.
Gigabit-per-second-class direct links to ground stations will be necessary during the short download time
of the direct communication page link from a LEO satellite. Optical communication systems are preferable for
this increasing communication demand.

Download full report
http://nt.tuwien.ac.at/fileadmin/topics/..._3.pdf.PDF
Reply
#2
to get information about the topic future satellite communication full report ,ppt and related topic refer the page link bellow

http://studentbank.in/report-trends-in-s...unications

http://studentbank.in/report-optical-sat...d-abstract

http://studentbank.in/report-optical-sat...ars-report

http://studentbank.in/report-satellite-c...7#pid40617

http://studentbank.in/report-mobile-sate...ull-report

http://studentbank.in/report-satellite-c...ull-report

http://studentbank.in/report-future-sate...tion--5509
http://studentbank.in/report-future-sate...munication

http://studentbank.in/report-satellite-c...pdf-report

http://studentbank.in/report-future-sate...509?page=3
Reply
#3

Hello there,

My name is Aly and I would like to know if you would have any interest to have your website here at studentbank.in promoted as a resource on our blog alychidesign.com ?

We are in the midst of updating our broken link resources to include current and up to date resources for our readers. Our resource links are manually approved allowing us to mark a link as a do-follow link as well
.
If you may be interested please in being included as a resource on our blog, please let me know.

Thanks,
Aly
Reply

Important Note..!

If you are not satisfied with above reply ,..Please

ASK HERE

So that we will collect data for you and will made reply to the request....OR try below "QUICK REPLY" box to add a reply to this page
Popular Searches: satellite communications answers, cyberonic internet communications inc, communications firms nyc, satellite communications by m richharia free download, aeronautical communications ppt in cse, seminar topics for mobile communications jamming, how satellite communicate what sensors are used latest trends used in satellites ppts,

[-]
Quick Reply
Message
Type your reply to this message here.

Image Verification
Please enter the text contained within the image into the text box below it. This process is used to prevent automated spam bots.
Image Verification
(case insensitive)

Possibly Related Threads...
Thread Author Replies Views Last Post
  DESIGN AND IMPLEMENTATION OF GOLAY ENCODER AND DECODER computer science crazy 2 22,580 26-08-2016, 03:46 PM
Last Post: anasek
  SATELLITE REMOTE SENSING AND DISASTER MANAGEMENT smart paper boy 2 2,094 04-03-2016, 02:44 PM
Last Post: seminar report asees
  Space Time Adaptive Processing smart paper boy 2 1,799 29-03-2014, 10:38 PM
Last Post: ramsaini
  ANTI THEFT ALERT AND AUTO ARRESTING SYSTEM FOR MUSEUMS AND JEWELRY SHOPS project report helper 11 14,177 12-08-2013, 09:57 AM
Last Post: computer topic
  AUTOMATIC VEHICLE ACCIDENT DETECTION AND MESSAGING SYSTEM USING GSM AND GPS MODEM smart paper boy 14 10,669 02-01-2013, 06:16 PM
Last Post: naidu sai
  Space Laser Communications: Systems, Technologies, and Applications seminar class 3 3,092 21-12-2012, 11:48 AM
Last Post: seminar details
  PON Topologies for Dynamic Optical Access Networks smart paper boy 1 1,760 12-12-2012, 12:40 PM
Last Post: seminar details
  PC To PC Optical Communication project topics 2 2,474 27-11-2012, 12:47 PM
Last Post: seminar details
  OPTICAL INTEGRATED CIRCUITS smart paper boy 1 1,712 13-11-2012, 12:39 PM
Last Post: seminar details
  RF Controlled Robot with Metal Detector and Wireless image and voice transmission(Mod seminar class 1 3,857 06-11-2012, 12:37 PM
Last Post: seminar details

Forum Jump: