Satellite Rapid Response System

The Satellite Rapid Response System (SRRS) is the ideal platform for satellite data processing. Completely modular, SRRS guarantees reliability and high performance in data processing, radically diminishing overhead.
Processing at every level is completely data-driven. No external intervention is necessary to manage the system.

Given its modularity and independence from specific missions, SRRS is a system that is continually evolving. The current data processors include a high number of instrument processors: Envisat/ASAR, Envisat/MERIS, Alos/AVNIR2, Terra-Aqua/MODIS, FAPAR (Fraction of Absorbed Photosynthetically Active Radiation), Metop/AVHRR3, Suomi-NPP/VIIRS and Radarsat2/SAR. Currently in beta testing but soon to be available are processors for: Ers1-Ers2/SAR, Alos/PALSAR.


The following table shows the characteristics of the SRRS processors.

The processor for ASAR data is available in two versions:

  • for processing from Level0 (Raw Data) with support for ASA_IM__0P products for generating images at medium and high resolution: IMM (150m) and IMP (30m)
  • for processing from Level1 with support for the following products: IMM (150m), APM (150m), IMP (30m), APP (30m), WSM (150m) and GM1 (1km)

The performances are of the highest level: from Level0 (30m resolution) the average processing time (in Range Doppler mode) for the generation of one image is less than one minute, regardless of the size of the product.

From Level1, the maximum processing time is less than 30 seconds on a single core processor.

The AVNIR2 processor is able to generate products and images at high resolution from Raw Data or higher levels. There are also two versions of the processor for AVNIR2:

  • for processing from Level0 (Raw Data) with the ability to generate Level1a products and photo-realistic images (10m)
  • for processing from Level1a/b for generating single images at high resolution (10m)

The processors include a module for atmospheric correction that is able to generate photo-realistic images at high resolution. Both processors offer record-breaking levels of performance. The Raw Data processor is able to process an AVNIR2 (8000×8000) scene in under 30 seconds.

The AVHRR3 processor is able to generate images at medium resolution from level1b products.

The processors include a module for top of atmosphere correction that is able to generate photo-realistic images. Processing is performed in real-time: a PDU (Product Dissemination Unit) is processed and projected in a couple of seconds.

The FAPAR Index (Fraction of Absorbed Photosynthetically Active Radiation) image provides information regarding the vegetation index of an area by indicating the amount of photosynthetically active radiation absorbed by vegetation canopies.

Our FAPAR processor is able to generate products in Real-Time starting from multi-spectral instruments such as Modis, Meris or VIIRS.

Meris was the first processor created for SRRS. It offers a highly advanced system of Quality Control and recovery for corrupted products. It is able to generate photo-realistic images at an astonishingly high speed starting from any Meris product (including Level0).

There are multiple versions of this processor:

  • for processing, from Level0 (Raw Data), Full Resolution products (MER_FR__0P) able to generate photo-realistic images at a 300m resolution
  • for processing, from Level0 (Raw Data), Reduced Resolution products (MER_RR__0P) able to generate photo-realistic images at a 1100m resolution
  • for processing, from Level1, Full Resolution products (MER_FR__1P, MER_FRS_1P) able to generate photo-realistic images at a 300m resolution
  • for processing, from Level1, Reduced Resolution products (MER_RR__1P) able to generate photo-realistic images at a 1100m resolution

Considering that the calculation is more demanding, the performance times are still incredibly fast, with 2Gb of MER_FR__0P (raw data) processed in under 1 minute.

The MODIS processor was created for the processing of Level1b products. It is able to generate photo-realistic images at resolutions of 250m, 500m and 1km.

It can generate false color images using any one combination of the MODIS bands.

Its speed allows it to generate a Modis scene at 250m resolution, projected and orthorectified (Terrain Correction) in under 4 minutes.

The VIIRS processor was created for the processing of Level1b products of the new SUOMI-NPP mission. It is able to generate photo-realistic images at resolutions of 375m and 750m.

It can generate false color images using any one combination of the VIIRS bands.

Its speed allows it to generate a VIRRS image (4 granules 3200×3072) at 750m resolution, projected, ortho-rectified and atmospheric corrected (surface reflectance) in under 15 seconds.

Night images can also be generated using VIIRS DNB bands (still in beta).

The SAR processor was created for the processing of Level1b products of the Radarsat2 mission. It is able to generate images at any product resolution.

Images are also projected and corrected to remove the antenna pattern.

Every image is also analyzed by the Ship Detection processor to extract Time/Position of the ships to be correlated with AIS information. Processing is almost in real-time. The overall accuracy is grater than 90%.


SRRS has an extremely advanced catalog for processed data. Regardless of the mission, the instrument, or the physical location of the processed data, the SRRS catalog offers an intuitive interface from which to access the processed products. No configuration is necessary in order to include a new processor or processing center; their number is virtually unlimited.

The SRRS catalog takes advantage of the most advanced web technology for visualization and user interaction. The interface adapts to the capabilities of the client through three levels of visualization: from the use of the Google Earth browser plug-in, to the static image, to the 2D interface created with Adobe Flash.

Compatibility is guaranteed with all of the most used browsers: Internet Explorer, Mozilla Firefox, Google Chrome and Safari, and including the newest mobile platforms (iPhone, iPad). The exchange of data between the client and the web server is completely asynchronous; the result is an interaction very similar to a standalone application, with the advantage of the client not having to install anything.


Here below a demonstration of the usage of the Web Interface.


The SRRS data-flow can be outlined with the following chart:



SRRS can receive the data to be processed from different sources such as: DAS (Direct Acquisition System), DDS (Data Dissemination System) or file repositories.

It is possible to do a quality control analysis on all ingested data.




Once the data have been elaborated, various modules of post-processing can be activated (even simultaneously) in order to further refine the results.

The post-processing modules include: Orthorectification (Terrain Correction), Image Projection, Mosaicing (Radar, Multispectral, FAPAR, etc.), Interferometry (Radar Data), Export in Google Earth format (KML/KMZ). If needed, Chelys can offer support in implementing and installing third party algorithms in the SRRS processing chain. All of the SRRS modules maintain all the system’s characteristics: they are Data-Driven, offer High-Performance and are reliable.

Miravi, our SRRS system installed in the European Space Agency (ESA) and functioning there since 2006, today can boast a record of 0 minutes of downtime.

If you are interested in our processing system and would like to know more, please contact us. We would be happy to give you any information you need and offer a temporary account so that you can access our SRRS platform and assess for yourselves the capabilities and potential of our system.

With the Satellite Rapid Response System, performance and reliability are no longer a problem.