INO-CNR Versione italiana


Radiation Explorer in the Far InfraRed - Prototype for Applications and Developments

REFIR-PAD campaign FTS Laboratory Photo gallery

REFIR Project
Field campaigns

REFIR project

The REFIR (Radiation explorer in the far infrared) project is a study, funded by European Union, of feasibility of a novel space-borne instrument that will measure the atmospheric spectral radiance of the Earth in the broad spectral range 100-1100 cm-1 from space with sufficient spectral resolution (0.5 cm-1) and signal-to-noise ratio (SNR > 100). More info are available at the Project webpage.

The main scientific objectives of the REFIR experiment are the measurement of the outgoing FIR radiation at the top of the atmosphere and the improvement of our knowledge of the principal drivers of this flux, e.g. temperature structure, water vapour, and clouds throughout the troposphere-surface system.

The REFIR concept consists of a far infrared FTS as the core instrument, of an embedded imager operating in an infrared 'window', sharing the same bore-sight as FTS, for scene/cloud signature identification in the FIR, of an add-on imager to provide multi-channel imagery, and of an absolute single-pixel radiometer with a single broad-band channel, used to measure the emitted radiation contextually with the spectral measurements.

The integration of all the systems leads to a very compact satellite instrumentation, working at room temperature, with an estimated overall mass of 70 kg and a power consumption of 80 W, including electronics. The overall data rate toward the ground station is foreseen to be of 170 kbps before on-board data compression.

Scientific rationale

In the next century planet Earth faces the potential hazard of climate changes, such as climate warming, rising sea level, deforestation, desertification, ozone depletion, acid rain, and reduction in bio-diversity. However many related important scientific questions remain unanswered. For example, while a significant global climate change, Man induced or not, is likely, its magnitude and timing (both at the global and regional level) are quite uncertain. Additional information on the rate, causes, and effects of global change is essential to develop the understanding of a such important physical process. Only through systematic, comprehensive research can scientists increase their knowledge of Earth’s climate and its variations, thereby providing guidance to decision makers.

The implementations of advanced observing techniques to eliminate gaps in the measuring network will complement the existing techniques and data to address the basic scientific problems of global change. Therefore, one of the major objectives of earth science in the coming decades is the development of complete and accurate long term data sets to study global change. Radiation is one of the most important themes, itself still articulated in a large variety of aspects. Of these aspects, the proposed project addresses the need for new data in a range as yet unexplored and the interaction between radiation, water vapour and clouds in the upper troposphere. The main scientific objectives of the REFIR concept are:

  • to measure the spectral radiance in the FIR (100 -1100 cm -1 ), a portion of the planetary emission to space that is not covered by any current or planned space mission;
  • to improve our knowledge on the distribution of the atmospheric constituents that modulate to a large extent the FIR emission to space, i.e.:
    • mid and upper tropospheric water vapour, using the strong spectral signature of water vapour in the FIR;
    • mid and upper tropospheric clouds, such as cirrus.

These objectives call for an instrument that is capable of wide spectral range, good throughput and sensitivity, and high spectral resolution. This naturally points to a FTS of some type. The FTS is the primary instrument of REFIR and represents the main object of this study.

Status of the project

REFIR project started with the feasibility study funded by European Union (EU) from January 1997 to April 2000. The activities included the Pre-Phase A (1997), the Phase-A (1998), and the Phase-B0 (1999) for the payload and the Pre-Phase A for the ground segment.

In 2001, the project has been proposed to the Italian Space Agency (Agenzia Spaziale Italiana, ASI) for the "Small Mission" Program.

CNR-INO via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy