Awards & Nominations
LEO has received the following awards and nominations. Way to go!
Global Nominee
TeachiSAR
High-Level Project Summary
In LEO (Low Earth Orbit) Team we have one main purpose: allow people who are not that familiarised with scientific concepts to enjoy the beauty of it! With this goal in mind, we will try to provide to the general public an easy explanation of the concept and different possible uses of the Synthetic Aperture Radar (SAR). In this line of thinking, we will try to show them how important it is for earth data collection, and how it can improve their daily lives. Arthur C. Clarke once said that "any sufficiently advanced technology is indistinguishable from magic", and that is precisesly what we mean to do here: let people enjoy for a little while the magic that beneath the SAR.
Link to Project "Demo"
Link to Final Project
Detailed Project Description
What on earth is a Synthetic Aperture Radar (SAR)? Well, first of all, we have to explain what a radar is. A radar is a system that detects objects over distances, using electromagnetic waves.
Okay, but you are still speaking klingon to me. What are electromagnetic waves?
Very well. An electromagnetic wave is the propagation of a distrubance of some property of the space. Before you complain, don´t worry, i know it seems complicated and that i am still speaking the Language of Mordor, but do not despair, explanation is coming.
An electromagnetic wave beheaves like this: if you throw a stone to the water, when the stone hits the surface, it produces a wave that keeps on going until it dissapears.
The radars that use these electromagnetic waves have the capacity of travelling...wait for it... through empty space and cover great distances!! They do not need a material mean. Kind of a giant and superpowerful bat´s sonic navigation system.
Since now we know what radars and an electromagnetics waves are, we have to learn one of the key techniques to understand what the SAR is: the synthetic opening.
This is a technique that is used to proporcionate the same capacity that it would have if it were equiped with a much bigger antenna. In order to do this, as the radar moves forward over his flying route and signals are combined or echoes are recieved by it. In a few words, it is the same technique used by satelites, but the satelite´s rout, is the Earth´s orbit.
The opening is basically what is used to gather the energy reflected and form an image.
Depending of the wide of the electromagnetic wave (of how broad is the wave the stone produced), different objects can be detected at different heights, like tree branches, its leaves, and even the humidity of the soil. Interesting, huh?
There are different types of synthetic opening antennas depending on the different forms they work.
One of these is the InSAR. The InSAR is in charge of capturing at least two images of the same examined location, and has to find the differences of the signals and produce a picture called "interpherograme".
There´s an improved evolution from the InSAR, the DInSAR. The DInSAR takes the difference between two interpherogrammes - the pictures- and, from them, obtains more precise data, which are used to control the sinking/uplifting or lateral deformation of surfaces.
Another way of functioning is the PolSAR, which uses the physical concept of polarization of electromagnetic waves, associated with the orientation of the waves when they are sent and/or recieved. Thanks to this, the capacity of basic radars is improved, since they can transmit and recieve in multiple polarizations, and it is now possible to see unique and different characteristics of each objectives. The more polarizations they have, more characteristics can be defined.
Finally, we have the PolinSAR, which is a tecnique that combines the polarization of the signals with the analysis of the differences in the images. In a few words, it combines the PolSAR way with the InSAR. The PolinSAR offers the potential of observing the Earth in three dimensions!!
All of these scanning modes can be used to measure changes in the topography of the Earth surface, having all of them very precise measures (even of 1cm!!!) or the geophysic vigilance of natural disasters such as earthquakes, vulcano´s eruptions, etc.
We hope by now you could, at least, take a glympse of the beauty of the magic behind the SAR tecnology. A Superman device built to observe, know, and prevent natural disasters.
But wait... SAR is not supernatural. It is the result of human cooperation, and scientific knowledge. If we, as mankind, cooperate in peace, sky is not the limit, neither is the galaxy, but The Universe!
Space Agency Data
For this project we make use of information provided by CONAE (about there SAR satellites, the SAOCOMs). We also studied information from NASA and ESA agencys. Some of the information about the RADARSAT and the NISAR was collected by us.
Hackathon Journey
What we can say about our experience in the Space Apps 2021 is that we could enjoy some time researching and working on a topic we like a lot.
We learned about the SAR antennas and how do they work. We also learned about the different types of SAR anntenas, and how are they designed to be mounted on a satellite.
We discovered the great amount of different space agencys SAR projects and the incredible amount of data that this anntenas can provide.
We chose this challenge beacuse we belived that everyone should have access to the information in a way that they can understand. Beacuse of that, we tried to make an approach to some of the main concepts related with SAR antennas.
References
https://earthdata.nasa.gov/learn/backgrounders/what-is-sar
https://earthdata.nasa.gov/learn/backgrounders/remote-sensing
https://www.asc-csa.gc.ca/eng/satellites/radarsat/default.asp
https://earth.esa.int/documents/10174/2700124/sar_land_apps_1_theory.pdf
https://www.youtube.com/watch?v=FJWzLxdSMyA
https://www.youtube.com/watch?v=wwfvKO9LUnA
https://www.sea-astronomia.es/glosario/efecto-doppler
https://www.tdx.cat/bitstream/handle/10803/6380/2_3_Satelites_con_SAR.pdf?sequence=10&isAllowed=y
https://earth.esa.int/documents/10174/950595/01_Wednesday_OCT2013_SAR_principles.pdf
https://www.researchgate.net/publication/50997117_PSInSAR_and_DInSAR_methodology_comparison_and_their_applicability_in_the_field_of_surface_deformations_-_A_case_of_NW_Slovenia
https://parviztarikhi.files.wordpress.com/2016/01/24-dec-2015-2-differential-in-sar-ps-insar-and-other-insar-applications_parviz-tarikhi.pdf
https://www.scielo.br/j/rbef/a/MLGprs97gC59rknLtMMb5gP/?lang=es
https://en.wikipedia.org/wiki/Interferometric_synthetic-aperture_radar
https://www.ifp.uni-stuttgart.de/en/research/remote_sensing/polln/
https://www.hindawi.com/journals/js/2015/316391/
https://informesdelaconstruccion.revistas.csic.es/index.php/informesdelaconstruccion/article/view/1036
Tags
#SAR, #radar, #electromagneticWaves, #EM, #forest
Global Judging
This project has been submitted for consideration during the Judging process.