September 11th, 2009 Category: Mosaics

The World from MERIS - Summer 2008

Over 2000 Level0 Reduced Resolution products from the MERIS instrument onboard the Envisat satellite were collected in the time period from January to August 2008 and processed by the Chelys Satellite Rapid Response System (SRRS) to generate high quality images.
The images were projected to obtain this composite view using MOSRI, a real time mosaic generation system, which automatically removes clouds and shadows while combining the data.

The new mosaic is available at different resolutions in the MOSAICS section of the EOSnap website.

Tags: Chelys Envisat Meris MOSRI SRRS Summer 2008 World Map | Comments |

August 26th, 2009 Category: Image of the day, Mosaics

SAR-Sharpened Mosaic of Italy

SAR-sharpening of Sardinia

The main image here was realized by merging ASAR and MERIS orthorectified Mosaics of Italy, generated by Chelys MOSRI, using a technique we call “SAR-Sharpening” due to its similarity to a method known as PAN-Sharpening.

PAN-Sharpening merges high resolution panchromatic and lower resolution multispectral imagery to create a single high resolution color image. “SAR-Sharpening”, on the other hand, uses a radar image instead of a panchromatic one.

In this image, we maintained the resolution of the MERIS sensor (250m) while greatly enhancing the level of detail using an ASAR mosaic with a 75m resolution.

The animated imagery focusing on Sardinia shows the improvements made through the SAR-Sharpening technique. Due to its resolution, the original color MERIS image clearly has a level of detail inferior to that of the ASAR image.

However, after the processing, the contours of the Italian terrain can be seen in great detail.

ENVISAT Sensor Coverage

ASAR operates simultaneously with the other ENVISAT instruments. The image on the left shows the swath positioning of ASAR along with those of the other sensors.

Chelys is currently exploring the possibility of enhancing the capabilities of their SRRS (Satellite Rapid Response System) processors, enabling them to automatically generate SAR-Sharpened images for all zones in which ASAR and MERIS images overlap.

Tags: ASAR Envisat Italy Meris Mosaics MOSRI Orthorectification SAR-Sharpening Sardinia SRRS | Comments (1) |

August 25th, 2009 Category: Mosaics

ASAR IMM Mosaic of Italy (Draft Version)

ASAR IMM Mosaic of Italy (Final Version)

This image of Italy is an ASAR Image Mode Medium Resolution Mosaic created with products acquired between January and July 2009.

These source images were generated starting from ENVISAT/Asar products, using the Chelys Satellite Rapid Response System.

They were then projected, orthorectified (with a NASA Digital Elevation Model of 3 arcseconds of resolution) and merged in this mosaic by Chelys MOSRI, a real time mosaic generation system, at the original resolution of 75 meters (0.000833 degrees per pixel).

The entire mosaic was generated in less than 1 minute. This is the latest version of the ASAR processing algorithm used by MOSRI which eliminates the banding effect created by merging the various original images.

Tags: ASAR Envisat Italy Mosaics MOSRI Orthorectification SRRS | Comments |

March 4th, 2009 Category: Earth Observation, Mosaics

Two weeks ago, we published a Meris FR Mosaic of Italy. The large number of interested users has led us to publish the entire Mosaic of Central/Eastern Europe. Starting today and over the next few weeks we will update the Mosaic section and the present post as soon as a new country is inserted.

Tags: Albania Austria Bosnia Bulgaria Croatia Czech Republic Germany Hungary Italy Macedonia Meris Montenegro Mosaic MOSRI Poland Romania Serbia Slovenia SRRS Switzerland Ukraine | Comments |