Periodic Reporting for period 1 - DRITUCS (Distributed Radar Interferometry and Tomography Using Clusters of Smallsats)
Okres sprawozdawczy: 2023-06-01 do 2025-11-30
Combating climate change is the most urgent challenge faced by humankind. Earth Observation satellites have an untapped potential to make a difference by providing invaluable information to start our climate action. This project aims at developing a new class of spaceborne radar sensors able to bring out this potential at an affordable cost.
Synthetic aperture radar is a well-established remote sensing technique that allows high-resolution imaging of the Earth surface in nearly all weather conditions, both in daylight and at night. By combining multiple images taken from different angles, we can create accurate digital elevation models and high-resolution tomograms that unveil the three-dimensional structure of vegetation, ice, and dry soil.
Whereas today such images are acquired sequentially with conventional satellites, compromising product quality and hindering the monitoring of fast dynamics, the DRITUCS project envisions distributed sensor concepts to acquire all data in a single pass, paving the way for effective and powerful monitoring of our planet. We exploit clusters of smallsats and build high-quality products from noisy and undersampled data. This makes a key contribution to multi-dimensional imaging theory and represents a paradigm shift from state-of-the-art techniques that demand expensive, high-quality imagery to create digital elevation models and tomograms.
Smallsats can be mass-manufactured and lead to low-cost solutions. They are a disruptive NewSpace technology that needs to be complemented by novel distributed approaches to replace and enhance large aperture, high power radar systems.
We are pursuing three scientific paths to lay the foundations of a) distributed multi-baseline interferometry, b) distributed tomography, and c) multiple-input multiple-output tomography that infers unique information about different scattering mechanisms in natural and man-made environments. The elaboration of theoretical models and the development of signal processing algorithms will be complemented by experimental demonstrations with drones.
The DRITUCS project represents a giant leap for radar remote sensing with a significant impact on numerous applications. It will pose the basis for future advanced Earth observation missions that will offer remarkable societal benefits and boost European capabilities in the emerging NewSpace sector.
Synthetic aperture radar is a well-established remote sensing technique that allows high-resolution imaging of the Earth surface in nearly all weather conditions, both in daylight and at night. By combining multiple images taken from different angles, we can create accurate digital elevation models and high-resolution tomograms that unveil the three-dimensional structure of vegetation, ice, and dry soil.
Whereas today such images are acquired sequentially with conventional satellites, compromising product quality and hindering the monitoring of fast dynamics, the DRITUCS project envisions distributed sensor concepts to acquire all data in a single pass, paving the way for effective and powerful monitoring of our planet. We exploit clusters of smallsats and build high-quality products from noisy and undersampled data. This makes a key contribution to multi-dimensional imaging theory and represents a paradigm shift from state-of-the-art techniques that demand expensive, high-quality imagery to create digital elevation models and tomograms.
Smallsats can be mass-manufactured and lead to low-cost solutions. They are a disruptive NewSpace technology that needs to be complemented by novel distributed approaches to replace and enhance large aperture, high power radar systems.
We are pursuing three scientific paths to lay the foundations of a) distributed multi-baseline interferometry, b) distributed tomography, and c) multiple-input multiple-output tomography that infers unique information about different scattering mechanisms in natural and man-made environments. The elaboration of theoretical models and the development of signal processing algorithms will be complemented by experimental demonstrations with drones.
The DRITUCS project represents a giant leap for radar remote sensing with a significant impact on numerous applications. It will pose the basis for future advanced Earth observation missions that will offer remarkable societal benefits and boost European capabilities in the emerging NewSpace sector.
A concept has been developed to improve the performance of a digital elevation model using one or two cubesat add-ons with small apertures flying in formation with a spaceborne radar interferometer with large apertures.
As a further step, a groundbreaking concept for digital elevation model generation using a cluster of satellites with small apertures has been proposed and demonstrated with airborne data. This includes a novel processing approach based on statistical principles (generalized maximum likelihood estimation), which has been formalized in the generalization of the theory of radar interferometry to the distributed case.
Aspects related to formation flying have been addressed with specific attention to the characterization of the safety of satellites flying in formation, the development of safety procedures for multi-satellite formations using a continuous control scheme, and the derivation of a model for delta-v evaluation for satellite formations with fixed across-track baselines.
An innovative concept for measuring the antenna pattern of a radar satellite using a smallsat flying in formation has been furthermore developed.
A model for evaluating the performance of phase synchronization for distributed radar systems based on a microwave link has been derived.
A ground-based demonstrator for multiple-input, multiple-output radar tomography has been built up to investigate scattering phenomena and test new algorithms.
As for the demonstration of distributed concepts using drones, a model to characterize geometric decorrelation for wideband radar interferometers and a model for volume decorrelation accounting for co-registration errors have been developed, a concept for volume structure retrieval using wideband interferometry has been devised, and the generation of digital elevation model using repeat-pass radar interferometry has been successfully demonstrated.
As a further step, a groundbreaking concept for digital elevation model generation using a cluster of satellites with small apertures has been proposed and demonstrated with airborne data. This includes a novel processing approach based on statistical principles (generalized maximum likelihood estimation), which has been formalized in the generalization of the theory of radar interferometry to the distributed case.
Aspects related to formation flying have been addressed with specific attention to the characterization of the safety of satellites flying in formation, the development of safety procedures for multi-satellite formations using a continuous control scheme, and the derivation of a model for delta-v evaluation for satellite formations with fixed across-track baselines.
An innovative concept for measuring the antenna pattern of a radar satellite using a smallsat flying in formation has been furthermore developed.
A model for evaluating the performance of phase synchronization for distributed radar systems based on a microwave link has been derived.
A ground-based demonstrator for multiple-input, multiple-output radar tomography has been built up to investigate scattering phenomena and test new algorithms.
As for the demonstration of distributed concepts using drones, a model to characterize geometric decorrelation for wideband radar interferometers and a model for volume decorrelation accounting for co-registration errors have been developed, a concept for volume structure retrieval using wideband interferometry has been devised, and the generation of digital elevation model using repeat-pass radar interferometry has been successfully demonstrated.
The generalization of the theory of radar interferometry to the distributed case (including airborne demonstration) represent a breakthrough result that provides an elegant solution to a problem open in the community since the beginning of the 2000s.