Satellite remote sensing has a particularly important role: many initiatives are now operating and others, with more advanced technological possibilities, are planned, often being the result of international co-operation. In this context it is necessary to establish an appropriate regulation of these activities, as the interests at stake are considerably divergent. Industrialised countries are in fact able to play an active role in the development of space activities, while developing countries, not holding the necessary technology, more or less passively witness such activities. The most controversial point is the interpretation of the principle of sovereignty, from which both parties move to reach opposite results. In favour of the industrialised countries one can invoke the principles of exploration and use on a non discriminatory basis, laid down by the Outer Space Treaty and also by the Universal Declaration of Human Rights, without mentioning the social and economic opportunities deriving from the development of activities bringing considerable benefits to mankind. It is equally true, though, that other principles exist, asserted to the point of sustain their common law status, such as the principle of permanent sovereignty on natural resources and the principle of non interference in the internal affairs of other States, which are the foundation on which the claims of the sensed States are based. My paper, taking into special consideration the UN Gen. Ass. Resolution 41/65 of 1986 on the "Principles Relating to Remote Sensing of the Earth from the Outer Space", would illustrate how the international co-operation is pushed on. The Principles on Remote Sensing of the United Nations do not mention the issues concerning the international commercialisation of the data, the notion of public benefit or intellectual property. The use of the data and the packaging of the relevant products require great investments by the industries and the latter are not willing to make these investments if a legal protection of the products and a technological followup for at least ten years is not assured. The most frequent form of protection of the remote sensing data, protecting from improper appropriation, reproduction and distribution, is the right of intellectual property. We will consider the remote sensing data protection foreseen in the United States, France, ESA and for primary data by an European Directive. A wider and inexpensive distribution of remote sensing data concerning the protection of the Earth's environment may be a concrete realisation of the international co-operation which extends to all countries the benefits deriving from a peaceful use out outer space. The market of space data concerning Earth observation is in full progress and it has not yet reached a sufficient maturity for the application of the laws of the market. At present the procedures change considerably from one country to another, and at times from one operator to another in the same country; they vary according to the nature of the data of the programs, of the categories of the users or of the use of the information. For the purpose of this study we shall consider the policy of the United States and of France and of the ESA, which have launched remote sensing satellites in outer space for the longest time, in order to stress the apparent differences. The study of the most emblematic data distribution policies shows an increasingly strong opening, albeit carried out in different manners, in favour of research in disciplines concerning the Earth. The initiatives of rules of the European Union concerning satellite data and the protection of environment prove the developing interest in this sector for a growing international co-operation.
