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Planning holidays
with the “view from above”

When planning their holidays, many people rely on recommendations, books, or assessments on the Internet. However, all this information has been generated some time in the past. Is it still relevant? High-tech satellites from space will increasingly provide “real-time” information from all over the world.

Beach holidays

Hotel at “top quality location”: Google Earth knows. A satellite image will show at a glance whether the four star hotel is actually directly situated at a noisy street and how large and wide the beach really is. The images are digitally taken by Earth observation satellites (e.g. IKONOS or the American WorldView) at an altitude of 600 to 800 kilometres and continuously radioed to Earth
(data rate: 300 Mbit/s). In Germany, the DLR ground stations in Oberpfaffenhofen and Neustrelitz are receiving the images.

Azure blue or “sludge”: to give a daily updated forecast on water quality, there will be no need for taking water samples soon. Evaluation of satellite images will do.

Eastern beach instead of western beach: checking the water quality via satellite also works for lakes. Here, the Balaton, the largest inland lake in Europe, in March 2012. Left: phytoplankton, right: sediments. When both rise at the same time, the water quality will decrease. Only in the eastern region, it’s “all signals blue”.

Algae bloom – not exactly enjoyable: an algae slick, like here in the North Sea in 2008, will spoil every holiday at the sea side (and may even be toxic for humans). For the sea, this is a real threat, since it prevents the light from reaching deeper water levels. Bad for plants and animals.

Holiday in town

A trip to town: danger of smog? Nitrogen dioxide (NO₂) in the breathing air is not healthy. Here on the satellite image: a global map on nitrogen oxide concentration, created with data from Sentinel-5P and its “Tropomi” sensor. The annual limit value within the EU is 40 µg/m³, marked in yellow and red on the map. There are many regions in North Rhine-Westphalia with “hardly breathable air”. Those who want to spend their holidays in a region with clean air, can look for an appropriate region here. The resolution of the satellite is at 3.5 to 7 kilometres. The values on the ground can be calculated from satellite data and used for an NO₂ forecast.

Is the air clean? Looking at ozone. Ozone in the stratosphere protects against sunburn,
ozone on the ground irritates the respiratory tract and may cause a headache. Measuring from
space instead of measuring at individual spots on the ground or by balloon continuously delivers
consistent data worldwide. Up to now, the weather satellite MetOp with various sensors is in charge
of ozone measurement. In future, this task will be assumed first and foremost by Copernicus with
Sentinel-4 and -5.

Holidays in nature

Hiking holidays in the forest? Satellite images show whether the local forests are in good shape or not – is there any forest, has it been damaged by forest fires or storms, and if so: has the forest sufficiently recovered yet? The picture shows an example: 14 years after a forest fire, the surface of about 6,000 hectares in Poland is still far from being reforested.

Updates soon to come every week? Since 2019, there has been a global forest land map for the first time in Earth’s history thanks to the German TanDEM-X satellite. With the intended radar satellite mission Tandem-L, this global forest map could be automatically updated in weekly intervals.

What about malaria? One million people die from malaria every year, particularly in Africa. Many holiday trips go to malaria regions, but mostly there are only widespread warnings. But how high is the actual risk for infection at the destination? Were concrete cases of illness recorded? How many? The MALAREO project, in which Remote Sensing Solutions GmbH from Baierbrunn took a leading role, aims at helping the African countries to record malaria cases on a map, but first and foremost to make forecasts from a combination of environmental data (vegetation, proximity to water areas, puddles, building development, weather forecast, and more) on how the risk of malaria is developing at a certain place, based on Earth observation data (i.e. from the German RapidEye satellites). The data is also to be used for improving the fight against malaria – for example through the exsiccation of swamps. Additional satellite data, for example from Sentinel-1, -2 and -3 as well as data from weather satellites could be used as well. There are ideas for this such as the project “EyeOnMalaria”.

Holidays on your doorstep

In Germany, there are many natural reserves with endangered animal and plant species and unique habitats, one of which in the Coesfeld district. They can be experienced thanks to theme-related round trips for cyclists and hikers described on the website www.erlebnis-naturerbe.de. EFTAS Fernerkundung Technologietransfer GmbH from Muenster establishes such applications with the help of remote sensing data: the software automatically recognises new objects on satellite images and includes them in the maps. In this way, touristic maps are kept up-to-date virtually as if by themselves. An interesting function as well: getting your tours planned as a round trip route.

Flight cancelled?
When volcanos bring air traffic to a halt

Eyjafjallajökull. Grímsvötn. Bárðarbunga. On Iceland, a volcano erupts; the ash cloud brings air traffic to a halt. Trip home adjourned indefinitely. When the Eyjafjallajökull erupted, on April 15, 2010 alone about 7,000 flights were cancelled since the ashes are a great threat to aircraft engines. The MetOp satellites have instruments on board that can detect sulphur dioxide – and thus volcano clouds. The DLR Earth Observation Center collects these data in real time and can derive corresponding information that can contribute to flight warnings or all-clear signals.

But how do scientists know whether the satellite data is really correct?
By checking them time and again on the spot. The ash concentration of volcanos (and more) is measured by a special DLR aeroplane from the site in Oberpfaffenhofen. The HALO Gulfstream G 550 (the successor of a Dassault Falcon 20E) is a flying laboratory picking its samples directly from the air – and all that at an altitude of up to 15,000 metres.

Copernicus: the European Earth observation programme

Satellites are documenting continuously and over a long period of time how the Earth changes: how does the climate change influence our environment? What is the impact of natural disasters – and could they possibly be predicted in order to save humans or enable faster help? How do cities change? How can agriculture and forestry be supported? How can data on air quality assist in preventing allergies, skin cancer, or asthma?

Earth observation is teamwork. This is why the EU initiated the European Earth observation programme Copernicus. The Copernicus programme is unique worldwide and very ambitious. What is more, the data obtained by Copernicus are accessible to everybody free of charge. Each citizen may download, explore, and further use this unique satellite data with a few mouse clicks only – and even currently updated. Every three years, data on forest coverage and other land coverage issues all over Europe will be updated with the help of Copernicus.

Copernicus is a programme in which the data of satellites, aeroplanes, ground stations and further sources flow together – for six areas:

Land surface monitoring
Monitoring of the maritime environment (seaways, protection of the sea)
Monitoring of the atmosphere (air quality)
Supporting disaster and crisis management (evaluation of information from natural disasters like earthquakes, volcano eruptions, and flooding)
Monitoring of the climate change
Civil security

The primary goal is to create a sound information basis for European and national environmental and security questions. But also the citizens, science, and industry are to benefit from these services.

In 1998, the starting pistol for Copernicus was fired. Since 2014, Copernicus has been a fully operational programme, both speaking in terms of information services and satellites. Important milestones were the launch of the first Sentinel-1A satellite on April 3, 2014 and that of the second satellite, Sentinel-2A, on June 23, 2015. Sentinel-5P was launched on October 13, 2017. In total, Copernicus comprises six Sentinel missions that are to be launched successively during the next years.

Already in space: the MetOp satellites

The three identically constructed MetOp satellites are weather satellites that perfectly complement the “normal” MeteoSat weather satellites. Whilst the MeteoSat satellites are “geostationary”, that means they always monitor the same part of the Earth’s surface from a fix point at an altitude of 36,000 kilometres, the MetOp satellites are “polar-orbiting”: they are orbiting the Earth and are capable of scanning it completely within 100 minutes and from an altitude of 817 kilometres only, which enables the depiction of more details.

The first satellite, MetOp-A, was launched in 2006, its successor, MetOp-B, has been in orbit since 2012, and MetOp-C since 2018. The satellites B and C were initially intended to be successors, however, since all three satellites are working well, now all satellites deliver high-quality data – in the same orbit, but offset by 120 degrees. On board the MetOp satellites, there are 13 measuring instruments capable of measuring the temperature and humidity profiles of the atmosphere as well as wind speeds or trace gases, but they also include receivers for emergency calls. For these satellites, too, successors are under development. The first satellite of the EUMETSAT Polar System – Second Generation (EPS-SG) is to be launched by the end of 2022.

The instruments on board MetOp:

The main objective of European satellites: making weather forecasts more precise and improving research of weather and climate correlations.

IASI – Infrared Atmospheric Sounding Interferometer – measurement of air and sea surface temperature as well as measurement of air humidity and content of trace gases
MHS – Microwave Humidity Sounder – measurement of air humidity in the atmosphere
GRAS – Global Navigation Satellite System Receiver for Atmospheric Sounding – measurement of the temperature and air humidity in the upper troposphere and the stratosphere with high vertical resolution
ASCAT – Advanced Scatterometer – measurement of wind speed and wind direction above the sea surface and of soil humidity over land
GOME-2 – Global Ozone Monitoring Experiment-2 – drawing up of ozone profiles of the atmosphere
AMSU-A1/AMSU-A2 – Advanced Microwave Sounding Units – measurement of maritime ice, temperature and air humidity under all weather conditions
HIRS/4 – High-resolution Infrared Radiation Sounder – measurement of air temperature and air humidity
AVHRR/3 – Advanced Very High Resolution Radiometer – image generation in the visible and near-infrared range of clouds and surfaces
A-DCS – Advanced Data Collection System – collection of data from other ground or sea-based observation stations
SEM-2 – Space Environment Monitor – particle detector consisting of Total Energy Detector (TED) for low-energy particles and Medium Energy Proton and Electron Detector (MEPED) for medium-energy particles
SARP-3 – Search And Rescue Processor
SARR – Search And Rescue Repeater – reception and transfer of emergency signals

Planning holidays with the “view from above”