Future trends and expected technological evolution of satellite infrastructure platforms
From INVESaTWIKI
FUTURE TRENDS AND EXPECTED TECHNOLOGICAL EVOLUTION IN THE FIELD OF EARTH OBSERVATION
Earth observation is one of the application in which satellites have gained a market niche
and also became indispensable to public services. But the applications are slow to develop
and are not able to cover the costs of development and renewal of satellites and ground
segments.
When we analyse the past evolution of the remote sensing activity, we observe a continuous
improvement in performances and precisely in the geometric resolution of the satellites.
From the first satellites with 100 m accuracy to now 1 m or even better, the satellites have
made tremendous progresses.
Also on another side, the general move towards « faster, better, cheaper » has affected this
domain and we now currently see operational satellites with sizes in the mini range. [1]
Geometric resolution
Improvements in geometric resolution and swath for new satellites are related to the decreasing in the size of individual transistors composing integrated circuits.
Satellite size
The development of small launchers, sometimes based or derived from reconverted missiles, has allowed or pushed the development of smaller spacecraft.
Access time
One of the characteristics of Earth observation satellites systems is the access time, i.e. the time needed to make available to a user an image he requested.
A possible scenario for the long term
Certainly small satellites are there for ever, or at least for long, but a number of problems are to be solved if we want to transform technical experiments, or lucky opportunities, in real and sustained business. From what has been said in the preceding paragraphs, one can derive a scenario for the future of Earth observation satellite.
NASA's future Earth observation plans
Improving life here on planet Earth is foremost in NASA ’s vision, and the larger purpose of NASA’s Earth science activities within its Science Mission Directorate (SMD). The research strategy is supported by information obtained from a variety of space vantage points and complemented by airborne and in situ observational data. [2]
FUTURE TRENDS AND EXPECTED TECHNOLOGICAL EVOLUTION IN THE FIELD OF GNSS
Technological trends
- Miniaturisation and receiver advances improve price versus performance and favour its use in portable devices.
- Advances in geographical information systems and digital mapping provide the necessary data to support new Location Based Services.
- Mobile communication technologies push the markets for positioning and timing services.
- The European GPS overlay infrastructure (EGNOS) in a first stage as well as Galileo in a second stage provide for quantum leaps in satellite navigation performances, hence stimulating demand and supply industries. [3]
Development of new and challenging applications
Like other technological domains new GNSS applications may be created by new combinations of existing elements. In the case of GNSS new
technical elements such as increased availability and accuracy or integrity and service guarantee may enable new classes of applications, e.g.
in public regulated or safety critical areas. A number of such new applications are already known on research level, others will be developed in
the future. An important issue to be solved for transferring such applications into marketable products or services is their operational feasibility,
e.g. safety certification or legal accountability.
Marine and aviation industries have traditionally accepted that their markets are governed by legislation, liability and type approval issues and
have accepted these constraints when adopting GPS technology. The land navigation and personal location markets have not been subject to
the same level of intervention. As the accuracy of GPS systems develop and especially when GALILEO is operational there will be situations
where the technology will be providing critical information.
A current example of use of GPS for time and location is in the ambulance services, where the U.K. Government has introduced a requirement
on response times. Presently the information obtained by using GPS and associated equipment is used to audit response times but it is not yet
mandatory nor is the equipment used subject to type approval. However it is not inconceivable that in the future this will be introduced. Current
certification of a product can be by either self certification or an independent third party, and it could be argued that approval and certification
could be a means of raising revenue.
One field in rather cheap, high volume applications where GPS has found only little success is personal security in emergency cases: GPS devices
are currently not suited for personal emergency alarm systems carried on person. Mainly practical issues hinder this kind of use: in-house
positioning, antenna not in a suitable position, long start-up time, power supply, expensive up-link, and more.
This enumeration leads to an important point: many challenging applications require an up-link to work. Neither GPS nor GALILEO provide this
kind of service. Typical up-link media are the GSM network and satellite data networks. Both of these up-links have their specific advantages
and disadvantages: e.g. GSM does not work world-wide or off-shore while satellite links require larger antennas and have a very limited data
throughput. One example of such an application is the localisation of overseas containers. Currently such systems built with GPS receivers and
satellite transceivers are hardly usable. Firstly, the energy supply is not solved (batteries have a very limited lifetime, solar panels are not suitable),
secondly, there is no ideal up-link media. This example shows that limitations coming from other system parts hinder or at least slow
down the break though of new challenging applications.
What is the consequence from this? Application of GPS or GALILEO must be analysed in a whole system context. The positioning function
alone does very unlikely lead to new challenging mass applications. This may be different in fields where the positioning itself is the main function
like avionics applications. The latter may be very important but are limited to quite small volumes. [4]
FUTURE TRENDS AND EXPECTED TECHNOLOGICAL EVOLUTION IN THE FIELD OF TELECOMMUNICATIONS
Two factors, epoch of the service start and
cost of the satellite, are picked up for consideration
of the future satellite. It is known that the
LEO mobile communications satellite is not
cost-competitive due to the surprised penetration
speed of the terrestrial cellular phones. On the
other hand, it is described that the broadcasting
satellite service is very cost-competitive to the
terrestrial broadcasting service.
Second, the cost-competitiveness of the futnre
communication satellite is examined in terms of
the cost and length of time to be developed. The
future satellite is based on a model of the future
communications satellite for next 30 years
which has been proposed. The satellite cost of
the 60-120 Gbps range of capacity, which is
called as a second generation communications
satellite, is estimated. It is shown that the second
generation communications satellite will be costcompetitive
in comparison with the terrestrial
system. It is also described that the third generation
communications satellite is more costcompetitive.
As far as the length of time for development
is concerned, it is described that the
small satellite is useful to develop the key technology. [5]
Factors defining cost - Competitiveness
Whether or not a satellite communications system is realized successfully depends on how its cost is competitive in comparison with other systems. In this chapter, the factors which define the cost-competitiveness are discussed. For the operational services, the cost-competitiveness means just less expensive than other systems. For the only one service system, it is important that the satellite communication service is started as soon as possible.
Cost-Competitiveness of mobile satellite
One of the factors which determine the cost-competitiveness is how the service can be provided at the optimal time. Further, the success of the mobile satellite communications system depends on how early and user friendly terminal to be developed.
Cost-Competitiveness of broadcasting satellite
It is said that the satellite broadcasting is very costcompetitive to the terrestrial broadcasting service. For example, the operation cost per year per household by the satellite broadcasting system is only one-fourth as much as the terrestrial broadcasting system. [5]
Cost of future communications satellite
The cost of the future communication satellite is discussed in this chapter. The purpose of the discussion is to examine whether or not the future communications satellite has cost-competitiveness.
Three generations approach of future communications satellite
The need of communications satellite will be unchanged in the future, because of the feature of satellite communications’. Considering the necessity of satellite communications in the future, three generations of communications satellites were proposed.
Cost estimation of the future communications satellite
The cost of a 2G satellite is estimated, considering the cost of bus, the cost of mission equipment and the development cost.
Consideration of cost-trend
In this section is shown the approximate cost trend of the communications satellite, with particular attention to the cost vs. generation power and the cost vs. capacity of the satellite.
Effective development for long time development
One of the barriers that the satellite communications system must cope is how to provide the services at the optimal time. It takes a long time to develop a satellite communications system, especially a satellite to develop new technologies with R&D. [5]
References
[1] D.Hernandez
"Possible scenario for future mission in Earth observation".
[2] S.P.Neeck, G.E.Paules, J.D.McCuistion Ramesh
"NASA's future Earth observation plans".
[3] Galileo Joint Undertaking
"Business in satellite navigation - An overview of market developments and emerging applications".
[4] G.Dippel-Hens (GALILEAN working group report)
"GNSS business issues".
[5] T.Iida
"Cost consideration for future communications satellite".
