Thematic Focus


Multiple classification methods are possible for outer space technologies, and various organizations opt for different approaches. Technologies covered are Global Navigation Satellite Systems (GNSS), Earth Observation (EO), Satellite Communication and Human Spaceflight.  This classification was selected after multiple iterations based on discussions with UNOOSA staff. Space technologies play an important role in many areas of activity within the United Nations.

As it is especially challenging for developing countries to access and use space-based information, the United Nations supports these Member States through satellite-derived information products, such as maps, and through capacity building and institutional strengthening.

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"Hydrology is the science that encompasses the occurrence, distribution, movement and properties of the waters of the earth and their relationship with the environment within each phase of the hydrologic cycle. The water cycle, or hydrologic cycle, is a continuous process by which water is purified by evaporation and transported from the earth's surface (including the oceans) to the atmosphere and back to the land and oceans. All of the physical, chemical and biological processes involving water as it travels its various paths in the atmosphere, over and beneath the earth's surface and through growing plants, are of interest to those who study the hydrologic cycle. There are many pathways the water may take in its continuous cycle of falling as rainfall or snowfall and returning to the atmosphere. It may be captured for millions of years in polar ice caps. It may flow to rivers and finally to the sea. It may soak into the soil to be evaporated directly from the soil surface as it dries or be transpired by growing plants. It may percolate through the soil to ground water reservoirs (aquifers) to be stored or it may flow to wells or springs or back to streams by seepage. The cycle for water may be short, or it may take millions of years. People tap the water cycle for their own uses. Water is diverted temporarily from one part of the cycle by pumping it from the ground or drawing it from a river or lake. It is used for a variety of activities such as households, businesses and industries; for irrigation of farms and parklands; and for production of electric power. After use, water is returned to another part of the cycle: perhaps discharged downstream or allowed to soak into the ground. Used water normally is lower in quality, even after treatment, which often poses a problem for downstream users. The hydrologist studies the fundamental transport processes to be able to describe the quantity and quality of water as it moves through the cycle (evaporation, precipitation, streamflow, infiltration, ground water flow, and other components). The engineering hydrologist, or water resources engineer, is involved in the planning, analysis, design, construction and operation of projects for the control, utilization, and management of water resources. Water resources problems are also the concern of meteorologists, oceanographers, geologists, chemists, physicists, biologists, economists, political scientists, specialists in applied mathematics and computer science, and engineers in several fields" (USGS, 2018)

Source: USGS. (2018) Hydrology.

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"Meteorology applies physical and mathematical methods to understand and forecast the processes that determine our weather. Weather forecasting is a highly complex process in which measurement technology and high performance computing are just as important as the laws of physics and chemistry. For a numerical weather forecast to work, atmospheric data need to be collected, quality controlled and assimilated with suitable integrated weather models. Forecasts are continuously being validated to obtain guidance for further improvements" (University of Vienna, 2018).

"Climatology has been regarded as a subdiscipline of Meteorology for quite some time. Early climate classifications refer to temperature and precipitation as the main factors determining regional climate. Climate parameters such as the occurence of vegetation types, the length of the vegetation period as well as the date of flower blossoms indicate the multidisciplinary character of climatology. Today, climatology or climate research is also referred to as geobiosphere dynamics. It describes the complex interrelations between climate subsystems such as the atmosphere, land, oceans and the biosphere. Despite the considerable growth of the field's scope, meteorology remains central to it, not least because the atmosphere represents the most important transport medium of the climate system" (University of Vienna, 2018).

Climate change has been called the defining challenge of our time. Its impacts are already evident and will intensify over time if left unaddressed. As part of the global array of networks of systems to monitor climate change, satellites now provide a vital and important means of bringing observations of the climate system together for a global perspective. Satellites contribute to the monitoring of greenhouse gases related to deforestation and industrial processes, the changing of ice in polar caps and glaciers, sea-level rise, temperature changes, as well as several essential climate variables. 

Source: University of Vienna. (2018)

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"Hotspots of biodiversity; wetlands they are home to more than 100,000 freshwater species, essential for many amphibians and reptiles, for bird breeding and migration. For humans, wetlands provide invaluable ecosystem services. They regulate water availability and quality, filtration, purification, and nutrient cycling as well as provide food for millions of people. They absorb shocks from natural events such as floods and droughts and regulate climate through carbon storage.

Despite their richness in biodiversity and ecosystem services, wetlands are one of the fastest declining ecosystems worldwide  – 64% of the world’s wetlands have disappeared since 1900. An increase in agricultural and urban land use change, infrastructure development, water diversion and pollution of air and water are some of the main factors causing their degradation and loss.

Information on the location of wetlands, their ecological character and their services is often sparse and difficult to find or access. Wetlands are often viewed as wastelands, to be drained, filled and converted to other purposes. Ignorance and misunderstanding of their role therefore results in limited coverage of wetlands in policies and management practices" (SWOS Portal, 2018)

Source: SWOS. (2018).

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"Despite typical glaciers’ massive sizes, monitoring them is not always an easy task. Only specific types of small glaciers are good measures of climate change. Some glaciers are too large to measure accurately, and others are simply too unpredictable. Once scientists find a suitable glacier, they must take satellite images of the ice for a minimum of five years and compare the results. They then have to look closely at the outside edge of the glacier (the glacier’s terminus). If a large percentage of the glacier’s edge is receding then the area around the ice is growing warmer, and if a large percentage is expanding then the area is growing cooler. When enough measurements from many different parts of the world have been gathered, the researchers can determine whether the earth is growing warmer or cooler" (NASA, 2018)

Source: NASA. (2018) At the Edge: Monitoring Glaciers to Watch Global Change.

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