Pansharpening and 8 Spectral Bands of WorldView-2

I was able to develop and test a code in R software using a simple pan sharpening formula (described here ) to create Pansharpened image of WorldView-2 (WV2) Multi-Spectral (MS) bands with high resolution Panchromatic (Pan) band. I have created a gif as shown in the figure above with Pan and MS ( a vegetation composite NIR2 in red, Yellow in green and Coastal in blue) images (data credit: esa).

Pansharpening is a process that merges/fuses high-resolution Pan data with medium-resolution MS data to create a high-resolution MS image (USGS).

WV2 is an imaging satellite of DigitalGlobe Inc., USA (a follow-on to WorldView-1 – WV1). WV2 sensor offers high resolution images in Pan 0.46 cm and unique MS 1.8 m at nadir. The MS bands are listed in the table below (credit: DigitalGlobe):

Band Name Wavelength Detail
Coastal Blue  400 – 450 nm New band
ƒƒAbsorbed by chlorophyll in healthy plants and aids in conducting vegetative analysis
ƒƒLeast absorbed by water, and will be very useful in bathymetric studies
ƒƒSubstantially influenced by atmospheric scattering and has the potential to improve atmospheric correction techniques
Blue 450 – 510 nm Identical to QuickBird
ƒƒReadily absorbed by chlorophyll in plants
ƒƒProvides good penetration of water
ƒƒLess affected by atmospheric scattering and absorption compared to the Coastal Blue band
Green 510 – 580 nm Narrower than the green band on QuickBird
ƒƒAble to focus more precisely on the peak reflectance of healthy vegetation
ƒƒIdeal for calculating plant vigor
ƒƒVery helpful in discriminating between types of plant material when used in conjunction with the Yellow band
Yellow 585 – 625 nm New band
ƒƒVery important for feature classification
ƒƒDetects the “yellowness” of particular vegetation, both on land and in the water
Red 630 – 690 nm ƒNarrower than the red band on QuickBird and shifted to longer wavelengths
ƒƒBetter focused on the absorption of red light by chlorophyll in healthy plant materials
ƒƒOne of the most important bands for vegetation discrimination
ƒƒVery useful in classifying bare soils, roads, and geological features
Red-Edge 705 – 745 nm New band
ƒƒCentered strategically at the onset of the high reflectivity portion of vegetation response
ƒƒVery valuable in measuring plant health and aiding in the classification of vegetation
NIR1 770 – 895 nm Narrower than the NIR1 band on QuickBird to provide more separation between it and the Red-Edge sensor
ƒƒVery effective for the estimation of moisture content and plant biomass
ƒƒEffectively separates water bodies from vegetation, identifies types of vegetation and also discriminates between soil types
NIR2 860 – 1040 nm New band
ƒƒOverlaps the NIR1 band but is less affected by atmospheric influence
ƒƒEnables broader vegetation analysis and biomass studies

I have also created a gif as shown in the figure above with Pan and MS ( a shadow composite NIR2 in red, Red Edge in green and Yellow in blue) images to compare results.

Panchromatic Band
Composite NIR2, Yellow and Blue (Before Pansharpening)
Composite NIR2, Yellow and Blue (After Pansharpening)

 

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Copernicus Sentinel 5P

Copernicus Sentinel 5P

Sentinel 5P March 01 to 05, 2019 are mapped using R software. Darker red areas are high levels of nitrogen dioxide (NO2) as shown over East of China, a highly industrialized populated area. Sentinel-5P have spatial resolution of 7 x 3.5 KM.

The Copernicus Sentinel-5P (S5P) data is available (here) for download since July 2018 to monitor air quality and changes in ozone over Antarctica. The TROPOspheric Monitoring Instrument (TROPOMI) is the single sensor on board of the S5P satellite. The S5P is the first of the atmospheric composition Sentinels (operational satellite missions supporting the Copernicus programme), launched in 2017, for a nominal lifetime of 7 years. S5P, is a gap-filler and a preparatory programme covering products and applications for Sentinel-5. The S5P mission will fill the gap between the end of the Ozone Monitoring Instrument (OMI) and SCIAMACHY exploitation and the Sentinel-5 mission (credit: ESA).

This high spatial resolution data is useful for air pollution to locate origin of key pollutants (trace gases such as sulfur dioxide in the atmosphere) and finding pollution hotspots. Measurements of atmospheric ozone from the Copernicus S5P satellite are now being used in daily forecasts of air quality. 

List of Sentinel-5P level 2 products are show in the table (credit: KNMI):

European Space Agency (ESA) – Sentinel-5P (credit ESA)

Data Download

The S5P data in “pre ops”  phase can be downloaded from the scihub https://scihub.copernicus.eu/ . I downloaded a level 2 NO2 file in netCDF format (.nc files).

search results are shown

Data visualization

The downloaded netcdf file first imported into “Panoply netCDF Visualization Software”

https://earth.usc.edu/files/ge-labs/EdGCM/Documentation/Panoply_Manual.pdf

The browser shows contents (variables) of the netcdf file.

The user can easily create a line plot.

2D plot with several map projections options

Copyright/Credit contains modified Copernicus Sentinel data (2018), processed by DLR/BIRA

One added value of Copernicus Atmosphere Monitoring Service (CAMS) ozone products compared to satellite total column retrievals is that CAMS provides 3D global fields. This allows structures like the Antrctic ozone hole to be viewed in a different way. This animation shows a cross section of the ozone layer (in partial pressure) over the South Pole from 1 July to 25 November 2018 and illustrates the development and recovery of the ozone hole.

Copyright/Credit Processed by CAMS/ECMWF

The reduction of ozone concentrations in the stratosphere and the formation of the ozone hole each year are caused by complex meteorological and chemical processes. Changes in the ozone between 7 July and 22 November 2018 are displayed here as a 3D rendered animation.

Copyright/Credit processed by CAMS/ECMWF

 

More Information available:

  • Tropomi.eu (KNMI R&D Satellite Observations here )
  • TROPOMI (the Netherlands here)
  • European Space Agency (ESA) Sentinel-5 Precursor / TROPOMI here
  • ESA Sentinel-5 Precursor launch campaign blog here
  • Sentinel-5 Precursor Level-2 Product User manual here
  • Research articles/presentations: link1, link2, link3, link4,

Flood Monitoring from Space – ESA’s Sentinel-1

Karachi, the largest city of Pakistan received heavy monsoon rain August 30, 2017. The flood in Karachi due to heavy rains is the continuation of the similar monsoon related flooding crisis in the South East Asia region (India, Bangladesh etc.).The Flood map below is derived (subset of Karachi city ) from European Space Agency (ESA)’s Copernicus Program SENTINEL-1 Synthetic Aperture RADAR (SAR) image acquired on September 01, 2017. The green color in the map shows the flooded region.

 

 

The total rainfall derived from satellite data (GPM IMERG) for Karachi from August 29-31, 2017 is shown in Figure below:

 

 

Monitoring Arctic Glaciers using Copernicus Sentinel-1 Satellites

ESA’s Climate Change Initiative in Glaciers_CCI Project, a team of researchers are using Copernicus Sentinel-1 SAR data with other optical data to monitor glaciers from space. The Negribreen glacier surge has been captured and shown in the animated gif (credit: ESA)

 

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

Related image

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

Related image

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)

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