The Experts below are selected from a list of 4611 Experts worldwide ranked by ideXlab platform
Manuel Martín-neira - One of the best experts on this subject based on the ideXlab platform.
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SMOS brightness temperature measurements and end-to-end calibration
2011 IEEE International Geoscience and Remote Sensing Symposium, 2011Co-Authors: Francesc Torres, Ignasi Corbella, Nuria Duffo, Manuel Martín-neiraAbstract:SMOS is the acronym for the Soil Moisture and Ocean Salinity mission by the European Space Agency (ESA) [1]. Its single payload, the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), was launched in November 2009. After a six months Commissioning Phase SMOS entered in operational mode in May 2010. Since then SMOS has been delivering a large amount of data to successfully produce the first relevant scientific results. In order to provide accurate measurements, MIRAS requires a complex multi-step calibration procedure that was successfully tested both during pre-flight ground tests and Commissioning Phase activities. Additionally, an assessment of SMOS system performance in terms of short and long term stability, radiometric sensitivity and radiometric accuracy was also produced. In this context, this work is devoted to provide a high level overview of MIRAS calibration scheme by focusing on the rationale behind it.
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IGARSS - SMOS brightness temperature measurements and end-to-end calibration
2011 IEEE International Geoscience and Remote Sensing Symposium, 2011Co-Authors: Francesc Torres, Ignasi Corbella, Nuria Duffo, Manuel Martín-neiraAbstract:SMOS is the acronym for the Soil Moisture and Ocean Salinity mission by the European Space Agency (ESA) [1]. Its single payload, the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), was launched in November 2009. After a six months Commissioning Phase SMOS entered in operational mode in May 2010. Since then SMOS has been delivering a large amount of data to successfully produce the first relevant scientific results. In order to provide accurate measurements, MIRAS requires a complex multi-step calibration procedure that was successfully tested both during pre-flight ground tests and Commissioning Phase activities. Additionally, an assessment of SMOS system performance in terms of short and long term stability, radiometric sensitivity and radiometric accuracy was also produced. In this context, this work is devoted to provide a high level overview of MIRAS calibration scheme by focusing on the rationale behind it. 1
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MIRAS Calibration and Performance: Results From the SMOS In-Orbit Commissioning Phase
IEEE Transactions on Geoscience and Remote Sensing, 2011Co-Authors: Ignasi Corbella, Francesc Torres, Nuria Duffo, Verónica González-gambau, Miriam Pablos, Israel Duran, Manuel Martín-neiraAbstract:After the successful launching of the Soil Moisture and Ocean Salinity satellite in November 2009, continuous streams of data started to be regularly downloaded and made available to be processed. The first six months of operation were fully dedicated to the In-Orbit Commissioning Phase, with an intense activity aimed at bringing the satellite and instrument into a fully operational condition. Concerning the payload Microwave Imaging Radiometer with Aperture Synthesis, it was fully characterized using specific orbits dedicated to check all instrument modes. The procedures, already defined during the on-ground characterization, were repeated so as to obtain realistic temperature characterization and updated internal calibration parameters. External calibration maneuvers were tested for the first time and provided absolute instrument calibration, as well as corrections to internal calibration data. Overall, performance parameters, such as stability, radiometric sensitivity and radiometric accuracy were evaluated. The main results of this activity are presented in this paper, showing that the instrument delivers stable and well-calibrated data thanks to the combination of external and internal calibration and to an accurate thermal characterization. Finally, the quality of the visibility calibration is demonstrated by producing brightness temperature images in the alias-free field of view using standard inversion techniques. Images of ocean, ice, and land are given as examples.
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First results on MIRAS calibration and overall SMOS performance
2010 11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, 2010Co-Authors: Ignasi Corbella, Francesc Torres, Nuria Duffo, Verónica González-gambau, Miriam Pablos, Israel Duran, Manuel Martín-neiraAbstract:After the successful launching of the SMOS satellite, the first continuous streams of data are being processed and carefully analyzed in the frame of the SMOS In-Orbit Commissioning Phase. Results regarding instrument calibration parameters retrieval, both internal and external, and brightness temperature imaging are presented. Images of ocean, ice and land are given as examples.
Pierre Femenias - One of the best experts on this subject based on the ideXlab platform.
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copernicus sentinel 3b gps l2c tracking tests during Commissioning Phase
Advances in Space Research, 2019Co-Authors: Javier Berzosamolina, Heike Peter, Jaime Fernandez, Pierre FemeniasAbstract:Abstract The Copernicus Sentinel–3B, the twin satellite of Copernicus Sentinel–3A, was launched on 25 April 2018. During its Commissioning Phase, the radar altimeter satellite has been flying in tandem with Sentinel–3A, only 30 seconds apart. This was mainly done for calibration and validation of the instruments on-board Sentinel–3B, maximizing the correlation of measurements taken by both Sentinel–3 satellites. The Commissioning Phase of Sentinel–3B and thus the tandem flight with Sentinel–3A has also been used to do several tests with the RUAG GPS receivers on-board Sentinel–3B. Future missions like the Copernicus Sentinel–C and –D satellites and the Copernicus Sentinel–6 (Jason-CS) satellite will carry an enhanced RUAG GNSS receiver (PODRIX). The GPS receivers on Sentinel–3B already have the capability to track the GPS L2C signal, which will become important for the future when the number of GPS satellites transmitting the L2C signal increase from currently 19 satellites up to the full GPS constellation. To test the receiver’s L2C tracking performance, the redundant receiver on Sentinel–3B has been running in parallel to the main receiver with L2C tracking enabled, either exclusively or in a mixed P(Y)&L2C configuration. The performance of this new signal is analysed in detail. The Sentinel–3B POD processing chain running at the Copernicus POD Service is used to determine orbits based on the P(Y) signals from the main receiver and based on C/A plus the new L2C signal from the redundant receiver, all of them publicly available via the Copernicus Open Access Hub. The Sentinel–3B POD performance is compared to that of Sentinel–3A and the results of the Sentinel–3B redundant receiver are directly compared to the results of the main receiver. Results are compared in terms of observation metrics, estimated orbit parameters and differences to internal and external orbit products. External orbit validation is done with Satellite Laser Ranging (SLR) measurements to the satellites. Although only 19 GPS satellites are currently broadcasting the L2C signal, the resulting orbits are of equivalent quality as the operational orbit products based on P(Y) data from the full GPS constellation. SLR mean and standard deviation of 0.37 ± 1.32 cm and 0.39 ± 1.43 cm for the main and redundant receiver solutions, respectively, confirm the orbit accuracy independent of the signals used for POD. The percentage of more than five observations per epoch is still very low with approx. 15 % considering the current L2C capable GPS constellation. Increase of this percentage is analysed based on a step-wise increase of the L2C capable GPS satellites up to a GPS constellation of 31 satellites.
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Copernicus Sentinel–3B – GPS L2C tracking tests DURING Commissioning Phase
Advances in Space Research, 2019Co-Authors: Javier Berzosa-molina, Heike Peter, Jaime Fernandez, Pierre FemeniasAbstract:Abstract The Copernicus Sentinel–3B, the twin satellite of Copernicus Sentinel–3A, was launched on 25 April 2018. During its Commissioning Phase, the radar altimeter satellite has been flying in tandem with Sentinel–3A, only 30 seconds apart. This was mainly done for calibration and validation of the instruments on-board Sentinel–3B, maximizing the correlation of measurements taken by both Sentinel–3 satellites. The Commissioning Phase of Sentinel–3B and thus the tandem flight with Sentinel–3A has also been used to do several tests with the RUAG GPS receivers on-board Sentinel–3B. Future missions like the Copernicus Sentinel–C and –D satellites and the Copernicus Sentinel–6 (Jason-CS) satellite will carry an enhanced RUAG GNSS receiver (PODRIX). The GPS receivers on Sentinel–3B already have the capability to track the GPS L2C signal, which will become important for the future when the number of GPS satellites transmitting the L2C signal increase from currently 19 satellites up to the full GPS constellation. To test the receiver’s L2C tracking performance, the redundant receiver on Sentinel–3B has been running in parallel to the main receiver with L2C tracking enabled, either exclusively or in a mixed P(Y)&L2C configuration. The performance of this new signal is analysed in detail. The Sentinel–3B POD processing chain running at the Copernicus POD Service is used to determine orbits based on the P(Y) signals from the main receiver and based on C/A plus the new L2C signal from the redundant receiver, all of them publicly available via the Copernicus Open Access Hub. The Sentinel–3B POD performance is compared to that of Sentinel–3A and the results of the Sentinel–3B redundant receiver are directly compared to the results of the main receiver. Results are compared in terms of observation metrics, estimated orbit parameters and differences to internal and external orbit products. External orbit validation is done with Satellite Laser Ranging (SLR) measurements to the satellites. Although only 19 GPS satellites are currently broadcasting the L2C signal, the resulting orbits are of equivalent quality as the operational orbit products based on P(Y) data from the full GPS constellation. SLR mean and standard deviation of 0.37 ± 1.32 cm and 0.39 ± 1.43 cm for the main and redundant receiver solutions, respectively, confirm the orbit accuracy independent of the signals used for POD. The percentage of more than five observations per epoch is still very low with approx. 15 % considering the current L2C capable GPS constellation. Increase of this percentage is analysed based on a step-wise increase of the L2C capable GPS satellites up to a GPS constellation of 31 satellites.
Ignasi Corbella - One of the best experts on this subject based on the ideXlab platform.
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SMOS brightness temperature measurements and end-to-end calibration
2011 IEEE International Geoscience and Remote Sensing Symposium, 2011Co-Authors: Francesc Torres, Ignasi Corbella, Nuria Duffo, Manuel Martín-neiraAbstract:SMOS is the acronym for the Soil Moisture and Ocean Salinity mission by the European Space Agency (ESA) [1]. Its single payload, the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), was launched in November 2009. After a six months Commissioning Phase SMOS entered in operational mode in May 2010. Since then SMOS has been delivering a large amount of data to successfully produce the first relevant scientific results. In order to provide accurate measurements, MIRAS requires a complex multi-step calibration procedure that was successfully tested both during pre-flight ground tests and Commissioning Phase activities. Additionally, an assessment of SMOS system performance in terms of short and long term stability, radiometric sensitivity and radiometric accuracy was also produced. In this context, this work is devoted to provide a high level overview of MIRAS calibration scheme by focusing on the rationale behind it.
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IGARSS - SMOS brightness temperature measurements and end-to-end calibration
2011 IEEE International Geoscience and Remote Sensing Symposium, 2011Co-Authors: Francesc Torres, Ignasi Corbella, Nuria Duffo, Manuel Martín-neiraAbstract:SMOS is the acronym for the Soil Moisture and Ocean Salinity mission by the European Space Agency (ESA) [1]. Its single payload, the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), was launched in November 2009. After a six months Commissioning Phase SMOS entered in operational mode in May 2010. Since then SMOS has been delivering a large amount of data to successfully produce the first relevant scientific results. In order to provide accurate measurements, MIRAS requires a complex multi-step calibration procedure that was successfully tested both during pre-flight ground tests and Commissioning Phase activities. Additionally, an assessment of SMOS system performance in terms of short and long term stability, radiometric sensitivity and radiometric accuracy was also produced. In this context, this work is devoted to provide a high level overview of MIRAS calibration scheme by focusing on the rationale behind it. 1
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MIRAS Calibration and Performance: Results From the SMOS In-Orbit Commissioning Phase
IEEE Transactions on Geoscience and Remote Sensing, 2011Co-Authors: Ignasi Corbella, Francesc Torres, Nuria Duffo, Verónica González-gambau, Miriam Pablos, Israel Duran, Manuel Martín-neiraAbstract:After the successful launching of the Soil Moisture and Ocean Salinity satellite in November 2009, continuous streams of data started to be regularly downloaded and made available to be processed. The first six months of operation were fully dedicated to the In-Orbit Commissioning Phase, with an intense activity aimed at bringing the satellite and instrument into a fully operational condition. Concerning the payload Microwave Imaging Radiometer with Aperture Synthesis, it was fully characterized using specific orbits dedicated to check all instrument modes. The procedures, already defined during the on-ground characterization, were repeated so as to obtain realistic temperature characterization and updated internal calibration parameters. External calibration maneuvers were tested for the first time and provided absolute instrument calibration, as well as corrections to internal calibration data. Overall, performance parameters, such as stability, radiometric sensitivity and radiometric accuracy were evaluated. The main results of this activity are presented in this paper, showing that the instrument delivers stable and well-calibrated data thanks to the combination of external and internal calibration and to an accurate thermal characterization. Finally, the quality of the visibility calibration is demonstrated by producing brightness temperature images in the alias-free field of view using standard inversion techniques. Images of ocean, ice, and land are given as examples.
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First results on MIRAS calibration and overall SMOS performance
2010 11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, 2010Co-Authors: Ignasi Corbella, Francesc Torres, Nuria Duffo, Verónica González-gambau, Miriam Pablos, Israel Duran, Manuel Martín-neiraAbstract:After the successful launching of the SMOS satellite, the first continuous streams of data are being processed and carefully analyzed in the frame of the SMOS In-Orbit Commissioning Phase. Results regarding instrument calibration parameters retrieval, both internal and external, and brightness temperature imaging are presented. Images of ocean, ice and land are given as examples.
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On-flight characterization of the SMOS payload during the Commissioning Phase
2009 IEEE International Geoscience and Remote Sensing Symposium, 2009Co-Authors: Ignasi Corbella, Francesc Torres, Nuria Duffo, Verónica González, Adriano Camps, Mercè Vall-llosseraAbstract:The SMOS in-orbit Commissioning Phase will start at launching and will last about 6 months. During this Phase an extensive activity will start, particularly aimed at providing full confidence on the products that the mission will produce during its operational Phase. As part of this activity, the payload MIRAS will be fully characterized using specific orbits dedicated to check all instrument modes. First, the procedures carried out during the on-ground characterization will be repeated so as to obtain a realistic temperature characterization and updated internal calibration. Additionally, a new concept of external calibration, consisting of periodic sky looks, will be tested providing the first-ever absolute instrument calibration parameters. Finally, the imaging capability of the instrument both in dual polarization and full polarimetric will be assessed using images of the Earth surface and the Galaxy. As a final result, the higher level overall performance parameters, such as stability, radiometric sensitivity, radiometric accuracy and absolute accuracy will be evaluated.
Francesc Torres - One of the best experts on this subject based on the ideXlab platform.
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SMOS brightness temperature measurements and end-to-end calibration
2011 IEEE International Geoscience and Remote Sensing Symposium, 2011Co-Authors: Francesc Torres, Ignasi Corbella, Nuria Duffo, Manuel Martín-neiraAbstract:SMOS is the acronym for the Soil Moisture and Ocean Salinity mission by the European Space Agency (ESA) [1]. Its single payload, the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), was launched in November 2009. After a six months Commissioning Phase SMOS entered in operational mode in May 2010. Since then SMOS has been delivering a large amount of data to successfully produce the first relevant scientific results. In order to provide accurate measurements, MIRAS requires a complex multi-step calibration procedure that was successfully tested both during pre-flight ground tests and Commissioning Phase activities. Additionally, an assessment of SMOS system performance in terms of short and long term stability, radiometric sensitivity and radiometric accuracy was also produced. In this context, this work is devoted to provide a high level overview of MIRAS calibration scheme by focusing on the rationale behind it.
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IGARSS - SMOS brightness temperature measurements and end-to-end calibration
2011 IEEE International Geoscience and Remote Sensing Symposium, 2011Co-Authors: Francesc Torres, Ignasi Corbella, Nuria Duffo, Manuel Martín-neiraAbstract:SMOS is the acronym for the Soil Moisture and Ocean Salinity mission by the European Space Agency (ESA) [1]. Its single payload, the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), was launched in November 2009. After a six months Commissioning Phase SMOS entered in operational mode in May 2010. Since then SMOS has been delivering a large amount of data to successfully produce the first relevant scientific results. In order to provide accurate measurements, MIRAS requires a complex multi-step calibration procedure that was successfully tested both during pre-flight ground tests and Commissioning Phase activities. Additionally, an assessment of SMOS system performance in terms of short and long term stability, radiometric sensitivity and radiometric accuracy was also produced. In this context, this work is devoted to provide a high level overview of MIRAS calibration scheme by focusing on the rationale behind it. 1
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MIRAS Calibration and Performance: Results From the SMOS In-Orbit Commissioning Phase
IEEE Transactions on Geoscience and Remote Sensing, 2011Co-Authors: Ignasi Corbella, Francesc Torres, Nuria Duffo, Verónica González-gambau, Miriam Pablos, Israel Duran, Manuel Martín-neiraAbstract:After the successful launching of the Soil Moisture and Ocean Salinity satellite in November 2009, continuous streams of data started to be regularly downloaded and made available to be processed. The first six months of operation were fully dedicated to the In-Orbit Commissioning Phase, with an intense activity aimed at bringing the satellite and instrument into a fully operational condition. Concerning the payload Microwave Imaging Radiometer with Aperture Synthesis, it was fully characterized using specific orbits dedicated to check all instrument modes. The procedures, already defined during the on-ground characterization, were repeated so as to obtain realistic temperature characterization and updated internal calibration parameters. External calibration maneuvers were tested for the first time and provided absolute instrument calibration, as well as corrections to internal calibration data. Overall, performance parameters, such as stability, radiometric sensitivity and radiometric accuracy were evaluated. The main results of this activity are presented in this paper, showing that the instrument delivers stable and well-calibrated data thanks to the combination of external and internal calibration and to an accurate thermal characterization. Finally, the quality of the visibility calibration is demonstrated by producing brightness temperature images in the alias-free field of view using standard inversion techniques. Images of ocean, ice, and land are given as examples.
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First results on MIRAS calibration and overall SMOS performance
2010 11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, 2010Co-Authors: Ignasi Corbella, Francesc Torres, Nuria Duffo, Verónica González-gambau, Miriam Pablos, Israel Duran, Manuel Martín-neiraAbstract:After the successful launching of the SMOS satellite, the first continuous streams of data are being processed and carefully analyzed in the frame of the SMOS In-Orbit Commissioning Phase. Results regarding instrument calibration parameters retrieval, both internal and external, and brightness temperature imaging are presented. Images of ocean, ice and land are given as examples.
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On-flight characterization of the SMOS payload during the Commissioning Phase
2009 IEEE International Geoscience and Remote Sensing Symposium, 2009Co-Authors: Ignasi Corbella, Francesc Torres, Nuria Duffo, Verónica González, Adriano Camps, Mercè Vall-llosseraAbstract:The SMOS in-orbit Commissioning Phase will start at launching and will last about 6 months. During this Phase an extensive activity will start, particularly aimed at providing full confidence on the products that the mission will produce during its operational Phase. As part of this activity, the payload MIRAS will be fully characterized using specific orbits dedicated to check all instrument modes. First, the procedures carried out during the on-ground characterization will be repeated so as to obtain a realistic temperature characterization and updated internal calibration. Additionally, a new concept of external calibration, consisting of periodic sky looks, will be tested providing the first-ever absolute instrument calibration parameters. Finally, the imaging capability of the instrument both in dual polarization and full polarimetric will be assessed using images of the Earth surface and the Galaxy. As a final result, the higher level overall performance parameters, such as stability, radiometric sensitivity, radiometric accuracy and absolute accuracy will be evaluated.
J. Mittermayer - One of the best experts on this subject based on the ideXlab platform.
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TerraSAR-X Commissioning Phase Execution Summary
IEEE Transactions on Geoscience and Remote Sensing, 2010Co-Authors: J. Mittermayer, B. Schattler, M. YounisAbstract:This paper provides an overview of the TerraSAR-X Commissioning Phase (CP). The overall CP planning and preparation is presented. The strategy for data-take (DT) command generation is discussed, and statistical reports summarize the acquired CP DTs. An overview summary on the main results in the different characterization and verification areas is provided together with synthetic aperture radar image examples.
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TerraSAR-X Commissioning Phase Execution and Results
IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008Co-Authors: J. Mittermayer, B. Schattler, M. YounisAbstract:The paper summarizes the results of the TerraSAR-X Commissioning Phase. The overall schedule and the planning tool are presented. The strategy for data take (DT) command generation and a statistic about all acquired data takes are discussed. An overview about the characterization/verification results is provided.
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IGARSS (2) - TerraSAR-X Commissioning Phase Execution and Results
IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008Co-Authors: J. Mittermayer, B. Schattler, M. YounisAbstract:The paper summarizes the results of the TerraSAR-X Commissioning Phase. The overall schedule and the planning tool are presented. The strategy for data take (DT) command generation and a statistic about all acquired data takes are discussed. An overview about the characterization/verification results is provided.
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IGARSS (2) - TerraSAR-X Instrument, SAR System Performance & Command Generation
IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008Co-Authors: J. Mittermayer, M. Younis, R. Metzig, U. Steinbrecher, C. Gonzalez, D. Polimeni, J. Boer, J. Marquez, S. Wollstadt, D. SchulzeAbstract:The paper presents selected results from the TerraSAR-X Commissioning Phase from instrument performance, SAR system performance and command generation.
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TerraSAR-X SAR System Verification
2007Co-Authors: J. Mittermayer, M. Younis, Thomas Fritz, B. Brautigam, R. Kahle, J. Marquez, R. MetzigAbstract:In 2007 TerraSAR-X, the first German Radar satellite for scientific and commercial applications, will be launched. The project is a public-private partnership between DLR and EADS Astrium GmbH. TerraSAR-X consists of a high resolution Synthetic Aperture Radar (SAR) at X-Band. The radar antenna is based on active Phased array technology operating in multiple SAR modes (Stripmap, ScanSAR and Spotlight) with various polarizations. The highly advanced instrument allows the active configuration of many different instrument parameters and settings. The pre-launch activities for the TerraSAR-X system include the preparation of a verification plan to be accomplished during the Commissioning Phase. The aim of this plan is to define a procedure including all sub-systems to ensure optimum end-products (SAR images). The procedure involves tasks such as calibration, characterization/verification of 1) SAR-instrument, 2) SAR system performance, and 3) orbit and attitude determination, as well as 4) product verification. Due to the complexity and re-configurability of the system it is not possible to verify all possible combinations and settings. This makes the verification plan construction and the scheduling of the individual activities a non-trivial task requiring expertise for both the complete system and detailed sub-system level. The paper starts by introducing the areas covered by the system verification plan. These are combined in a block diagram for the basic SAR product verification flow. A detailed description of the philosophy behind the system verification plan is given. This is crucial to ensure proper interaction and to avoid conflicts during the detailed planning. The overall system verification plan is used to derive the verification matrix which identifies the tasks required for SAR System and Product release during the Commissioning Phase. Specifically, the bottom level outcome of this matrix are the Commissioning Phase data take and their sequence of acquisition. However, the matrix is also a driver for the development of the tools required for the evaluation/analysis of the data take measurements. The paper will present both the verification matrix as well as the overall Commissioning Phase schedule. First results and trends of the TerraSAR-X Commissioning Phase with respect to SAR system and SAR products verification will be presented. The paper gives an insight and is intended to be a valuable reference for the development of system verification strategies of state-of-the-art and future SAR systems.