SARTREK Newsletter: December 2003

In This Issue:

1. RELEASED: RADARSAT-2 SOAR Program Request for Proposals
2. SOAR Coordination Office
3. RADARSAT-2 Calibration Program
4. Application Potential of RADARSAT-2 Multi-polarization / Fully Polarimetric Capabilities
5. RADARSAT-2 Program News
6. ASAR 2003 Workshop Proceedings Now Available

RELEASED: RADARSAT-2 SOAR Program Request for Proposals

The RADARSAT-2 Science and Operational Applications Research (SOAR) Program Request for Proposals (RFP) has been officially released. The SOAR program is intended for research and the development of information products to address commercial and practical needs using the new capabilities of RADARSAT-2 - helping make the scientifically possible operationally practical.

The RADARSAT-2 satellite boasts a number of features & benefits aimed at providing users with additional benefits for use in their operations, including:

• Multi-polarization capabilities
• Fully polarimetric capabilities
• Ultra fine SAR products (3m)

The RFP process involves two steps:

Step 1: Letters of intent are to be submitted on-line between February and June before December 30 2004. Once submitted, the SOAR committee will review the letters of intent and provide feedback regarding the eligibility of your proposal.

* The submission of Letters of Intent for the SOAR program has been extended to December 31, 2004

Step 2: If the letter of intent receives favourable reviews, a full proposal may be submitted. Full proposals are due at the end of November 2004 and successful applicants will be notified by April 2005. Launch is scheduled in 2006 with data availability planned for Q2 of 2006.

The complete SOAR document is available for download on the RADARSAT-2 information page

SOAR Coordination Office

We are pleased to announce the formation of the new SOAR Coordination Office located at the Canadian Space Agency (CSA) in Saint-Hubert, Quebec. The purpose of the Office is to:

• Provide information regarding the SOAR program and its guidelines during proposal submission and symposia preparations;
• Act as a liaison between the SOAR Program Partners and Sponsors;
• Provide administrative support to the program, including the coordination of data acquisition and delivery services by the Sponsors.

SOAR is a joint program between MacDonald Dettwiler, RADARSAT International and the Canadian government through the Canadian Space Agency and the Canada Centre for Remote Sensing. The Coordination Office provides a single point of contact for applicants to the program to gain up-to-date information and support.

RADARSAT-2 Calibration Program

Calibration will be an important consideration for many of the expected SOAR proposals. The RADARSAT-2 program has defined a plan in which to calibrate the SAR system as quickly and efficiently as possible. The RADARSAT-2 SAR system includes more than 200 different beams with multi-polarization capabilities, and it is the intention to provide radiometric calibration for all products and polarimetric calibration for all fully polarimetric data.

The Amazon rainforest region will be imaged to provide the radiometric and polarimetric calibration data. Equivalent data obtained with previous C-band satellite SAR systems has been demonstrated to provide the measurement consistency required for effective calibration.

The aim is to achieve full calibration of the primary imaging modes within six months of the start of the Mission Operational Phase.

Full paper

Application Potential of RADARSAT-2 Multi-Polarization / Fully Polarimetric Capabilities

We continue to explore and review the RADARSAT-2 polarization capabilities with respect to the objective to understand the methodologies to extract meaningful information that meets client requirements. The SOAR program will provide additional insights as to where the RADARSAT-2 capabilities will enhance the information needs of our clients.

We have compiled a non-comprehensive summary of expectations concerning the various combinations of RADARSAT-2 polarization and how they will support various user requirements. This summary is based on a document prepared in 2001 by the Canadian Centre for Remote Sensing under contract to the Canadian Space Agency titled Applications Potential of RADARSAT-2, A Preview. We have added information from both internal and external projects and papers that have been presented over the last few years.

Feel free to provide feedback on your application successes with multi and fully polarized data sets - particularly if you have results to share based on your experiences and research that will add to our knowledge, or are an ENVISAT ASAR user and/or researcher.

RADARSAT-2 Program News

The spacecraft bus for RADARSAT-2 is in production! As seen in the photos below, Alenia technical staff are assembling the bus unit. The bus contains all the systems and interfaces necessary to operate and maintain the satellite and support the SAR payload. The bus performs the following functions:

• Power Generation and Storage: The Electrical Power subsystem is responsible for generating, storing, and regulating electrical power for the satellite. Power is generated from the two solar array wings, each consisting of three panels. The solar panels are designed to generate 2400 Watts at End-Of-Life. Power is stored on-board in a Nickel-Hydrogen (NiH2) battery.
• Attitude Determination and Control: RADARSAT-2 is a 3-axis stabilised, zero-momentum satellite. Various sensors and actuators determine and maintain the spacecraft's orientation, and ensure that the spacecraft meets its performance requirements for precisely pointing the SAR antenna in either left- or right-looking mode and for controlling the transition between these two modes.
• Payload Data Handling and Transmission (PDHT): The acquired SAR image data, along with ancillary (e.g. GPS) data, is stored on-board and transmitted to the ground via the X-Band communications downlink. Image data will be encrypted using the Data Encryption Standard (DES).
• Propulsion Sub-System: The spacecraft has six 1-Newton thrusters which are used initially to manoeuvre the spacecraft into its operational orbit (correcting any launch dispersions). The thrusters then maintain the spacecraft's orbit to keep the ground track within a strict tolerance range (better than ± 5km, with a goal of ± 1km) during its operational lifetime. RADARSAT-2 will use mono-propellant hydrazine fuel.
• Thermal Subsystem: : In its sun-synchronous orbit, one side of RADARSAT-2 is usually exposed to continuous sunlight. Between the left- and right-looking imaging mode, different areas of the SAR antenna are exposed to varying intensities of sunlight. Thermal control is required to reflect or dissipate the heat of the sun on the spacecraft body and SAR antenna, as well as to dissipate the heat that is generated internally by the satellite's electronics.
• Orbit Determination and Control: The primary method for orbit determination is through the use of on-board Global Positioning System (GPS) receivers, and by Precision Orbit Determination software which will be implemented by MDA. Orbit control is achieved by the Propulsion System.
• Telemetry, Tracking and Command (TT&C): The TT&C subsystem is the communications interface between the spacecraft and the Ground Segment. Commands, such as when to conduct imaging operations, are up-linked to the spacecraft. Telemetry data - information on the status or health of various sub-systems on the spacecraft - are recorded throughout each orbit, and downlinked to the ground. Two omni-directional S-Band antennae, positioned on opposite corners of the spacecraft, provide ground-facing communications in any spacecraft orientation. Up-linked command data will be encrypted.

The Bus will be delivered in early 2004, following the final assembly, integration and test activities at Alenia.

ASAR 2003 Workshop Proceedings Now Available

The proceedings of from the fifth Advanced SAR Workshop held at CSA in Saint-Hubert, Quebec June 25-27 are now available on CD. The workshop is a biennial event that reviews the progress of advanced synthetic aperture radar (SAR) technology. Extending over three days, the workshop was divided into 13 sessions, giving a complete overview of SAR technology development. The workshop gathered 94 speakers and over 180 participants from 15 different countries.

The proceedings contain a number of presentations on calibration and polarimetric applications, including:

• SAR Calibration (including discussions on RADARSAT-2 approaches)
• SAR Applications (including maritime surveillance and operations, ice, and land cover)
• Polarimetric Interferometry

The workshop proceedings have been mailed to registered participants. If you would like to receive a copy of the proceedings, please contact the workshop secretary Karine Boies

Please note that quantities available are limited.