ITU-R REPORT RS.2178 PDF

Introduction

Information about climate, climate change, weather, precipitation, pollution or disasters is a critically important everyday issue for the global community. Earth observation activities allow to provide this information, which is required for the daily weather forecast and prediction, studies of climate change, for the protection of the environment, for economic development (transport, energy, agriculture, building construction, ...) and for safety of life and property.

One gets so used to this that one is inclined to forget that this information is either based on measurements, or gathered and distributed via radio frequency applications. However, one does consider the continuous delivery of information about the atmosphere or weather to be a routine, although a very complex one, and not "just science", like no one does consider the operation of a mobile telecommunication system as a science.

Satellites provide the most cost-efficient, if not the only, way to monitor the environment of the entire Earth, both land, sea, and air. Unique capabilities of Earth exploration-satellite service (EESS) satellites include observing wide-areas non-intrusively and uniformly (by using the same instrument) with the ability to rapidly target any point on Earth, including remote and inhospitable places, and to continue with a series of observations over a long period of time. Through these capabilities, the EESS brings many benefits to society in both the non-profit and commercial sectors.

Radio frequencies represent scarce and key resources used by Earth observation systems to measure and collect data upon which analyses and predictions, including warnings, are based or processed. This information is disseminated to governments, policy makers, disaster management organisations, commercial interests and the general public.

On a more general basis, the utmost importance of radio spectrum for all Earth observation activities, either ground or space based, is to be stressed, in particular with regards to the global warming and climate change activities, but also for applications that are nowadays taken for granted such as the daily weather forecast and prediction.

Mankind's influence on the atmosphere of the planet Earth has expanded in recent decades from the local scale of urban pollution to global scale effects such as the ozone hole. This is also indicated by more and more comprehensive evidence of the enhanced greenhouse effect.

Monitoring terrestrial chemical constituents is essential in the middle atmosphere corresponding to the stratosphere and the mesosphere. At altitudes higher than the tropopause (10 to 18 km from the pole to the tropics), ozone molecules play an important role by absorbing the ultraviolet (UV) radiation of the Sun, which is harmful to mankind, flora and fauna, and in general to any terrestrial life if the amplitude of the radiation reaching the ground is strong. For more than 50 years, man has imprudently used chlorofluorocarbons (Freon's) going up into the stratosphere where they are destroyed by UV radiation, freeing large quantities of chlorine monoxide, the most dangerous destroyer of ozone molecules.

Committee on Earth science and applications from space of the U.S. National Research Council, concluded in 2007 in its publication "Earth science and applications from space: National imperatives for the next decade and beyond," as follows:

"The world faces significant environmental challenges: shortages of clean and accessible freshwater, degradation of terrestrial and aquatic ecosystems, increases in soil erosion, changes in chemistry of the atmosphere, declines in fisheries, and the likelihood of substantial changes in climate. These changes are not isolated; they interact with each other and with natural variability in complex ways that cascade through the environment across local, regional, and global scales. Addressing these societal challenges requires that we confront key scientific questions related to ice sheets and sea-level change, large-scale and persistent shifts in precipitation and water availability, transcontinental air pollution, shifts in ecosystem structure and function in response to climate change, impacts of climate change on human health, and the occurrence of extreme events, such as severe storms, heat waves, earthquakes, and volcanic eruptions."

To this respect, the worldwide effort to build a Global Earth Observation System of Systems (GEOSS) over the next 10 years within the Group on Earth Observation (GEO) represents an essential step and is presented in this Report. Indeed, GEOSS will work with and build upon existing national, regional, and international systems to provide comprehensive, coordinated Earth observations from thousands of instruments worldwide, transforming the data they collect into vital information for our society.

The development of new, mass-market and added-value radio applications is putting increasing pressure on the frequency bands used for Earth observation purposes. This competing for spectrum presents the potential risk of limiting Earth observation applications in future. At particular risk is passive satellite sensing which involves the measurement of very low-levels of naturally emitted radiation in a number of radio frequency bands. These bands are sensitive to more than one geophysical variable and therefore must be used together to derive a number of different quantities. The radio frequencies required to do this are determined by fundamental physics and are unalterable. Continuity of observations using these bands is also essential to the monitoring and assessment of climate change.

In spectrum management it is becoming more and more important to estimate the value of different use of spectrum. In the case of spectrum used for Earth observations, this estimate may be quite difficult, as the benefits can relate to the society as a whole and they may be difficult to be quantified as they are realised over a very long period of time. Therefore, comparison with the benefits of services in the commercial field is often difficult and frequently leads to unbalanced conclusions.

These difficulties in evaluating and recognizing the benefits of spectrum use for Earth observation applications resulted in Resolution 673 (WRC-07) inviting ITU-R to carry out studies on possible means to improve the recognition of the essential role and global importance of Earth observation radiocommunication applications and the knowledge and understanding of administrations regarding the utilization and benefits of these applications.

Part A gives examples of attempts to quantify the economic and societal value of the use of spectrum by Earth observation applications which are obviously significant.