Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Improved detection of radio waves from space

04.05.2015

Geodesy is the scientific discipline that deals with the measurement of the Earth. One of the measurement techniques it employs uses radio waves from far-distant objects in space to determine factors such as the movement of tectonic plates. A high frequency amplifier promises to boost the performance of the radio telescopes this method requires.

Together with their Spanish colleagues from the Instituto Geográfico Nacional and the University of Cantabria, researchers from the Fraunhofer Institute for Applied Solid State Physics IAF in Freiburg have developed a very sensitive high frequency amplifier for radio telescopes used on Earth.


The dish of the radio telescope based in Yebes, Spain, measures more than 13 meters across.

© Instituto Geográfico National

The amplifier generates extremely little internal electromagnetic noise and will help measure our planet from space more precisely than ever before. The position of radio telescopes will be pinpointed with a precision to approximately one millimeter – a tenfold improvement in accuracy.

The measurement technique relies on radio telescopes picking up radio waves emitted by objects in space; the more accurately scientists can determine the positions of the radio telescopes, the more precisely they can measure various characteristics of the Earth.

“Because the radio telescopes are placed far apart at sites all round the world, they detect the radio waves at different times,” explains Dr. Mikko Kotiranta, a researcher at Fraunhofer IAF. Determining the exact distances between telescopes becomes a matter of the accuracy with which these time lapses can be measured – a process in which every picosecond, or trillionth of a second, counts.

Combining several of these measurements allows scientists to determine with the greatest accuracy variables such as the length of day and the movement of tectonic plates, poles and the Earth’s axis. “This information is useful for a number of applications, for instance determining satellites’ orbits with greater precision,” says Kotiranta.

The radio waves in question come from quasars, which are supermassive black holes at the center of galaxies billions of light years away from Earth. As with any other celestial object, quasars are constantly moving through space, but they are so far away from Earth that from our perspective they appear to stand still. We also see them as a point-like objects, which makes them ideal fixed points of reference for measuring the Earth.

By the time the radio waves are picked up by the radio telescopes, however, the signal is extremely weak. This is because of the enormous distance they have had to travel through space. Another obstruction to obtaining a clear signal detection is the interfering electromagnetic noise generated by all bodies at temperatures above absolute zero – 0 Kelvin or minus 273 degrees Celsius.

From an electromagnetic perspective, absolute zero would be the temperature required for total silence. “The general rule is that the colder it is, the less noise is generated,” says Kotiranta.

A low-noise amplifier that works in the freezing cold

To address this problem, the researchers took a previous model of the amplifier and put it in an extra-cold freezer at a temperature of 22 Kelvin, or minus 251 degrees Celsius. Extreme conditions that exceed the capacities of electronic components. Or perhaps not?

To find out, the researchers at Fraunhofer IAF developed a mathematical model that describes how radio frequency circuits should be designed if they are to function at extremely low temperatures. Teaming up with their project partners, the researchersdeveloped a microwave amplifier in the cleanroom and the laboratory, which was then tested at different temperatures.

They used the results to refine the model so that its forecasts corresponded more closely with the recorded data. This updated model provided the basis for a new amplifier prototype, which the researchers continued to refine until they finally succeeded in developing a low-noise amplifier that fulfilled all the necessary requirements: an amplifier that works perfectly even at extremely low temperatures and the interfering electromagnetic noise of which was minimized.

This technology is currently in use in a newly constructed radio telescope belonging to the Instituto Geográfico National in Yebes in Spain. “Initial trials are already being conducted,” says Kotiranta. The project partners plan to start using the radio telescope for geodesy purposes from September onwards, for instance to measure the movement of tectonic plates.

Three more large radio telescopes – each with a diameter of over 13 meters – are currently being constructed. These telescopes will be built in the Azores and the Canary Islands, and are due to enter service by the end of 2015 and 2016 respectively. The four new telescopes will form part of the worldwide network of radio telescopes known as VGOS (Very Long Baseline Interferometry 2010 Global Observing System).

“Most telescopes date back to the 1970s and 1980s, and their technology is no longer state of the art. The new generation of telescopes will offer considerably more performance and provide us with information about our planet that is more accurate than ever before,” finishes Kotiranta.

Britta Widmann | Fraunhofer Research News

More articles from Physics and Astronomy:

nachricht New photoacoustic technique detects gases at parts-per-quadrillion level
28.06.2017 | Brown University

nachricht Supersensitive through quantum entanglement
28.06.2017 | Universität Stuttgart

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

New photoacoustic technique detects gases at parts-per-quadrillion level

28.06.2017 | Physics and Astronomy

Funding of Collaborative Research Center developing nanomaterials for cancer immunotherapy extended

28.06.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>