Synthetic Aperture RADAR (SAR) Remote Sensing Basics and Applications

This post will provide an overview of the basics of Synthetic Aperture RADAR (SAR) and applications. The main topics discussed in the listed documents include: SAR basics, backscatter, geometry, interferometry, polarimetry, SAR data, data acquisition, available data sets/access to data, data analysis tools, future missions and SAR applications.

What is RADAR? – RAdio Detection And Ranging

What is SAR? – Synthetic Aperture Radar – Synthetic Aperture Radar (SAR) is an active remote sensing technology that uses microwave energy to illuminate the surface. The system records the elapsed time and energy of the return pulse received by the antenna (PDF).

Image result for SAR satellite systems (source: unavco)

Synthetic Aperature Radar (SAR) Tutorials

  1. A Tutorial on Synthetic Aperture RADAR – ESA (PDF )  (PDF) (Radiometric Calibration of SAR Image)
  2. The Canada Centre for Mapping and Earth Observation (CCMEO) is considered an international leader in the development and use of synthetic aperture radar or SAR sensors.  From space, SAR can image the Earth’s surface through clouds and in total darkness.  This makes it a tremendously useful sensor for monitoring Canada’s changing landmass and coastal zones. CCMEO scientists have worked with the Canadian Space Agency in the development of both RADARSAT 1 and RADARSAT 2  satellite missions.  Their research has led to improved data quality through enhanced sensor design and post-launch calibration and validation activities.
  3. This training manual introduces and explains Interferometric Synthetic Aperture Radar (InSAR), including applications for data from the Envisat ASAR sensor and how to combine Envisat and ERS images to produce interferograms and differential interferograms.
  4. Synthetic Aperture RADARs Imaging Basics (PDF)
  5. NOAA SAR Manual (PDF)
  6. Synthetic-aperture imaging from high-Doppler-resolution measurements (PDF)
  7. A Mathematical Tutorial on Synthetic Aperture RADAR (PDF)
  8. Remote sensed ground control points with TerraSAR-X and TanDEM-X (PDF)
  9. Interpolation and Resampling (Link)
  10. ESA’s InSAR Principles (Link)
  11. ESA Advanced Training Course on Land Remote Sensing (Link)
  12. A Strategy for Active Remote Sensing Amid Increased Demand for Radio Spectrum (2015) (Chapter 1) (Chapter 2) (Chapter 3) (Chapter 4) (Chapter 5) (Chapter 6) (Chapter 7) (Chapter 8) (Chapter 9) (Chapter 10)

Synthetic Aperature Radar (SAR) Applications

  1. Infrastructure Monitoring with Spaceborne SAR Sensors (Link)
  2. Soil Moisture Measurements by SAR (PDF)
  3. Marine applications: Sea Ice (Link), Marine Winds (PDF), Oil Pollution (PDF)
  4. Land deformation (Link)
  5. Flood Mapping (PDF) (PDF)

Video Tutorials on SAR

Earthdata Webinar Series: Discover Simplified SAR Solutions at NASA ASF DAAC

NASA ARSET: Basics of Synthetic Aperture Radar (SAR), Sessions 4

This video is part of the Australian National University course ‘Advanced Remote Sensing and GIS’ (ENVS3019 / ENVS6319)

PCI Geomatics Live stream- Advanced SAR training course

SAR Data Processing Shri Shashi Kumar (ISRO)

Synthetic Aperture Radar Applications

Space Based SAR Systems

RADARSAT-1

Launched in 1995, C-band HH-polirzation, Canadian Space Agency

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RADARSAT-1 mission overview, spacecraft, references (Link)

Data Product Specification (Link)

Applications (Link) (PDF)

RADARSAT is an advanced Earth observation satellite system developed by Canada to monitor environmental change and to support resource sustainability (Link)

RADARSAT-2

Launched in 2007, C-band quad-polirzation, MDA, CSA

RADARSAT-2 mission overview, spacecraft, references (Link)

Data Product Specification (Link)

Applications (Link) (PDF)

The many advances in RADARSAT-2 technology were developed to respond to specific needs for radar data in hundreds of environmental monitoring applications in Canada and around the world (Link).

SENTINEL 1

Launched in 2014/15, C-band dual-polirzation, European Space Agency (ESA)

Image result for sentinel-1

SENTINEL-1 mission overview, spacecraft, references (Link)

Data Product Specification (Link)

Applications (Link) (PDF)

SENTINEL-1 provides data feeding services for applications in the Copernicus priority areas of maritime monitoring, land monitoring and emergency management (Link).

RISAT-1

Launched in 2012, C-band single/dual & Circular Polirzation, Indian Space Research Organization (ISRO)

Image result for RISAT-1

RISAT mission overview, spacecraft, references (Link) (PDF) (PDF)

Data Product Specification (Link) (PDF)

Applications (Link)

Active Microwave Remote Sensing provides cloud penetration and day-night imaging capability. These unique characteristics of C-band (5.35GHz) Synthetic Aperture Radar enable applications in agriculture, particularly paddy monitoring in kharif season and management of natural disasters like flood and cyclone.

Terra SAR-X / TanDEM-X

Launched in 2007/10, X-band quad polirzation, DLR/Astrium, Germany

Image result for TERRA SAR -X Tan DEM X

Terra SAR-X  (TSX) mission overview, spacecraft, references (Link) (Link to documents)

Data Product Specification (Link)

Applications (Link)

TanDEM-X (TDX) mission overview, spacecraft, references (Link)

Data Product Specification (Link)

Applications (Link)

TanDEM-X – the Earth in three dimensions (Link) (Link)

ALOS-2

Launched in 2014, L-band quad polirzation, Japanese Space Agency (JAXA)

 

 

 

 

ALOS-2 mission overview, spacecraft, references (Link)

Data Product Specification (CEOS Link) (Geotiff Link) (Link)

Applications (Link to papers) (PDF)

JAXA conducted research and development activities for ALOS-2 to improve wide and high-resolution observation technologies developed for ALOS in order to further fulfill social needs. These social needs include: 1) Disaster monitoring of damage areas, both in considerable detail, and when these areas may be large 2) Continuous updating of data archives related to national land and infrastructure information 3) Effective monitoring of cultivated areas 4) Global monitoring of tropical rain forests to identify carbon sinks.

COSMO SkyMed

Launched in 2007/10, 4 Satellites X-band dual polirzation, ASI/Italy

 

 

 

 

COSMO SkyMed mission overview, spacecraft, references (Link)

Data Product Specification (Link) (PDF)

Applications (PDF) (PDF) (PDF) (PDF)

COSMO SkyMed offers high resolution X‐Band SAR (synthetic aperture radar) images. Despite its enormous potential, research investigating the possible uses in archaeology is still very scarce, especially of one which works solely with single date analysis starting with a single SAR scene (PDF).

HJ-1C-SAR

Launched in 2013,  S-band (HH or VV) polarization CRESDA/CAST/NRSCC, China

Image result for HJ-1C-SAR product description

HJ-1C-SAR mission overview, spacecraft, references (Link)

Data Product Specification (Link)

Applications (Link) (PDF)

HJ-1A/B/C corresponding to environment and disaster monitoring and forecasting small satellite constellation A/B/C include two optical satellites – HJ-1A/B and one radar satellite HJ-1C, which can carry out large-scale, all-weather and 24h dynamic monitoring for ecological environment and disaster (Link).

PAZ

Launched in 2014, X-band quad polarization, Ministry of Defense, Spain

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PAZ mission overview, spacecraft, references (Link) (Link)

Data Product Specification (Link) (Link)

Applications (Link)

PAZ is a Spanish radar technology satellite designed to address not only security and defense requirements, but also others of civilian nature. It is capable of daily taking more than 100 images of up to 25 cm resolution, both day and night, and independently of weather conditions (Link).

Kompsat-5

Launched in 2013, X-band dual polarization, KARI, Korea

Image result for Kompsat-5 Kari -band product description

Kompsat-5 mission overview, spacecraft, references (Link) (Link) (Link)

Data Product Specification (Link)

Applications (Link) (Link)

SAOCOM – 1/2

Launched in 2016/18, L-band quad polarization, CONAE/ASI, Argentina

Image result for SAOCOm L-band product description

SAOCOM- 1/2 mission overview, spacecraft, references (Link) (PDF) (PDF)

Data Product Specification (Link) (PPT)

Applications (Link)

The Argentina National Space Activities Commission (CONAE) launched a new Earth observation satellite that will support disaster management efforts. SAOCOM 1A is the first of a constellation of two radar satellites. The remote sensing mission aims to provide timely information for disaster management as well as monitoring services for agriculture, mining and ocean applications.

NASA-ISRO Systhetic Aperture Radar (NISAR)

will launch in 2020 (Link)

NISAR mission overview, spacecraft, references (Link) (PDF)

Data Product Specification (Link) (Link)

Applications (Link) (Videos)

The launch of the first dual-frequency synthetic aperture radar (SAR). The data collected by the L-band (produced by NASA) and S-band (produced by ISRO) SAR systems aboard the NISAR satellite and processed into cloud-free, ultra-sharp imagery will facilitate cutting-edge research into some of the planet’s most complex processes, including ecosystem disturbances, ice-sheet dynamics, earthquakes, tsunamis, volcanoes, and landslides.

RADARSAT Constellation Mission (RCM)

Will launch in 2019 three satellites, C-band quad compact polirzation, Canadian Space Agency (CSA) (Link)

Image result for RADARSAT Constellation Mission product description

RCM mission overview, spacecraft, references (Link)

Data Product Specification (Link) (Link)

Applications (Link) (PDF) (PDF)

RCM Pre-launch Preparedness Using Simulated Products (Link)

RCM Compact Polarimetry (CP) (PDF) (PDF) (PDF) (PDF)

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Detecting rainfall from the bottom up: SM2RAIN

SM2RAIN is a simple algorithm for estimating rainfall from soil moisture data.

The SM2RAIN code and the soil moisture derived rainfall data sets are freely available and can be downloaded here. The description of SM2RAIN and of its performance can be found in Brocca et al. (2013) and Brocca et al., 2014. (also here at IRPI-CNR website)

Immagine1

Here you can find two recent TALKS (IPWG 2016SMAP 2016) showing the latest results with the applications of SM2RAIN to multiple satellite soil moisture products (ASCAT, QUIKSCAT, RAPIDSCAT, AMSR-E, AMSR2, SMOS, and SMAP). In the paper by Massari et al. (2014) it is shown that SM2RAIN-derived rainfall from in-situ soil moisture observations even improves flood modelling (see also here, Italian media). In this paper by Brocca et al. (2015) the application of SM2RAIN to synthetic and in situ observations at several sites in Europe further underlines the robustness of the method. In Ciabatta et al. (2015) the integration of SM2RAIN with state-of-the-art products has provided significant improvements for rainfall estimation over the whole Italian territory. The latest application of SM2RAIN is for irrigation assessment, see here the project and a first overview paper.
Other scientist are using SM2RAIN in Mexico, in the Tibet Pleateau, and on a global scale. Click on the image below for the current list (PDF) of SM2RAIN papers with link to full text.

ERS SAR data available via ESA On-The-Fly service – Content – Earth Online – ESA

ESA is pleased to announce that SAR data from the ERS-1 and the ERS-2 missions have been made available for direct download via the (A)SAR On-The-Fly (OTF) service.

With this release, users now have access to (A)SAR level 1 products from both ERS missions and from Envisat, covering Image Mode (IMS, IMP), Wide Swath (WSS) and Alternating Polarisation (APP, APS). All data are delivered as standard scenes in Envisat format.

Processing and download of the generated “standard scene” Level 1 products is performed directly through the EOLI-SA user interface. A user manual and FAQ page are available to get started.

 

Source: ERS SAR data available via ESA On-The-Fly service – Content – Earth Online – ESA

Satellite remote sensing data for hydrological analyses and water resources management

Satellite remote sensing data for hydrological analyses and water resources management are listed below:

  1. Groundwater Discharges: Researcher uses satellite data to analyze the groundwater discharges. Locating ground-water discharge areas
  2. Land Water Boundaries: Satellite data has been used to convert surface features into land cover maps including water body. Water body detection and delineation with Landsat TM data
  3. Management of Water: Satellite images has important use in water management. The USA government agencies are using satellite data for monitoring decreasing water resources, especially in western part of USA by estimating past and present water use and evapotranspiration (ET). The Landsat program and water resources information needs in the United States
  4. Monitoring Flooding: Satellite image are in use to map flood damage area. Case studies
  5. Monitoring Lakes: Satellite data helps to understand and monitor changes in lake water volume (snow melt) and quality (due to spring run-off). Monitoring lake inventories and health
  6. Watersheds Mapping: Satellite data are used to map the watersheds area. Determining land use change within the dog river watershed
  7. Wetlands: Landsat data can be downloaded of few decades back, so it can be used to track the number and area of the wetlands. Mapping wetlands and riparian areas