Written by Felipe José Cerignoni, IMAFLORA; Paula A. Paz, CIAT; Africa Flores, SERVIR- Amazonia
The week of 13 -17 august was conducted the first in-person training on the Application of remote sensing of Synthetic Aperture Radar (SAR) in ecosystems, which took place in Bogota – Colombia. This training is part of a series of activities focused on building capacity and decision-making capabilities provided by SAR- CBC project, a NASA funded project carried out by the Alaska Satellite Facility (ASF), JPL, the University of Alabama in Huntsville, the Institute of Hydrology, Meteorology and Environmental Studies (IDEAM) in conjunction with NASA SERVIR.
The training was given by Dr. Franz J. Meyer, chief scientist at ASF and Africa Flores, Science Coordination Lead of SERVIR-Amazonia. Most of the 40 participants in the training included public officials from local municipalities, members of the IDEAM team, The Regional Autonomous Corporations of Colombia (CAR), students from local universities, and SERVIR-Amazonia partners (CIAT and Imaflora).
SAR- Synthetic Aperture Radar – produces fine resolution images from a radar system. They are active sensors carried by satellites that emit radio waves at different frequencies in the microwave and do not need sunlight to «illuminate» the targets, these radio waves suffer little or no interference from the atmosphere making it possible to acquire images in places where clouds prevail over long periods of time, such as rainforests.
With these images it is possible to perform robust time series analysis and detect changes in the landscape, such as flooded areas, deforestation, degradation, regeneration, fires, agricultural areas, and biomass variation, thus becoming great complementary information to images from optical sensors aboard satellites like the Landsat series and Sentinel-2 for example.
Currently the main operating satellite that produces free radar imagery is the European Space Agency’s Sentinel-1 (frequency:C-band), however in 2021 it is scheduled to launch the NASA-ISRO SAR Mission NISAR (frequency: L-band) and TanDEM-L (frequency: L-band) from DLR (German Aerospace Center) , these missions will allow for a better understanding of biomass changes in dense forests.
The focus of this training was to bring radar basic concepts, pre-processing and applications of SAR data closer to the technicians who produce relevant information about ecosystems monitoring. And who often face issues working with optical data due to weather events and/or high cloud cover.
SERVIR-Amazonia plans to keep developing the capacity of users in the Amazon in these novel techniques. Through the NASA-SERVIR Science Coordination office there are plans in place to work with SAR experts in the region to provide more trainings and complement current analysis based only on optical datasets. Stay tuned for more updates!
For more information about SAR and remote sensing:
- Fundamentals of Remote Sensing -> WEBINAR: https://arset.gsfc.nasa.gov/webinars/fundamentals-remote-sensing
- Fundamental of Imaging SAR -> WEBINAR : https://arset.gsfc.nasa.gov/disasters/webinars/intro-SAR
- SAR Handbook -> Basic concepts, and methodologies for forest monitoring and biomass estimation, developed by SERVIR and NASA, download: https://t.co/NAAgLeAv0e?amp=1.
- Currently available tool to Radiometric Terrain Correction online:
- InSAR data processing: http://hyp3.asf.alaska.edu/
- Earth Big Data (EBD): http://earthbigdata.com/
- Google Earth Engine using SNAP: https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S1_GRD
- Media: NASA ARSET: A Q&A Session on Radar Remote Sensing featuring Prof. Franz J. Meyer https://www.youtube.com/watch?v=6iN_-obEBJ0&feature=youtu.be
Upcoming In Person Training:
- Oct 2019: SAR-CBC Training «SAR in Disaster Monitoring“, Quito, Ecuador. Host Organization: UCE & National Institute for Research in Geology, Mining, Metallurgy (INIGEMM)