This report describes the physical principles underpinning cold atom interferometry (CAI) and shows how they can be leveraged to develop high-performance inertial and gravity sensors; the distinguishing properties and the maturity level of such sensors will also be assessed. \nProof-of-principles demonstrations have been made for CAI-based accelerometers and gyroscopes, which can enable long-term autonomous navigation and precise positioning for ships, submarines, and satellites. CAI-based gravimeters and gravity gradiometers have been developed and are being tested on the ground; satellite-based systems could in the future be used to monitor the Earth gravity field. This would allow a better understanding of several geophysical and climate phenomena which require long-term policies solidly supported by data. \nQuantum sensors based on cold atom interferometry may therefore impact existing and future EU programmes on space, defence, and Earth observation. This report provides background knowledge of the field to a non-specialist audience, and in particular to EU policymakers involved in technology support and potential applications.
This report describes the physical principles underpinning cold atom interferometry (CAI) and shows how they can be leveraged to develop high-performance inertial and gravity sensors; the distinguishing properties and the maturity level of such sensors will also be assessed. \nProof-of-principles demonstrations have been made for CAI-based accelerometers and gyroscopes, which can enable long-term autonomous navigation and precise positioning for ships, submarines, and satellites. CAI-based gravimeters and gravity gradiometers have been developed and are being tested on the ground; satellite-based systems could in the future be used to monitor the Earth gravity field. This would allow a better understanding of several geophysical and climate phenomena which require long-term policies solidly supported by data. \nQuantum sensors based on cold atom interferometry may therefore impact existing and future EU programmes on space, defence, and Earth observation. This report provides background knowledge of the field to a non-specialist audience, and in particular to EU policymakers involved in technology support and potential applications.
This report assesses the potential of gyroscopes and accelerometers based on cold atom interferometry (CAI) for space and defence applications, by analysing their strengths and weaknesses in comparison with devices based on other working principles. Indeed, it is widely recognized that quantum sensors based on atomic interferometry provide absolute measurements with the potential for high sensitivity and long-term stability. This last property is particularly valuable for accelerometers and gyroscopes to be used for inertial navigation, since it guarantees precise positioning without the need for frequent recalibrations, a shortcoming which affects several devices presently in use. \nHigh-performance inertial sensors play an important role both in space applications, where gyroscopes are widely used e.g. to orientate a satellite and its on-board communications and sensing equipment, and in defence, where gyroscopes and accelerometers constitute the core of the inertial measurement units to be used for autonomous navigation, e.g. in GNSS-denied conditions. The EU has a well-established role in space with the Copernicus and Galileo programmes, and a fledging but increasing involvement in the defence industry. An independent assessment of a quantum technology such as cold atom interferometry which may in time acquire a significant role in these fields is a precondition to advance well-grounded suggestions for EU policy initiatives.
This report provides an assessment on cold atom interferometry (CAI) gravity sensing for Earth Observation (EO), and is intended as an instrument to facilitate the interactions between the different communities involved in the definition of a related satellite mission. Indeed, the definition of the objectives of future gravity missions and of the technologies needed for their implementation is the result of complex negotiations and compromises: geodesy and geophysics researchers detail the scientific requirements dictated by their investigation areas (e.g. solid Earth dynamics, ocean mass and heat transport, ice sheets and glaciers evolution), policymakers express their concerns and their priorities (e.g. natural hazards risk assessment, ground water monitoring, floods and droughts forecast), engineers and technology experts devise and implement the most suitable techniques to actually build the satellite and its gravity sensing payload. \nAs we will show in this report, the scientific consensus is that the scientific objectives of a next generation gravity mission (NGGM) to be deployed within a ~10 year timeframe can be achieved by upgrading established technologies already used in gravity-measuring satellites. Transformative technologies such as CAI-based gravity sensors leveraging Bose Einstein Condensates (BEC) of ultra-cold atoms may come to play a role in the longer term, provided that several technology challenges are overcome; in addition, further interdisciplinary work and the simulation of detailed mission scenarios are needed to fully establish their actual usefulness with regards to the attainment of future gravity missions scientific objectives.\nThe scientific community seems to agree on the opportunity of an intermediate stepping stone, which could take the form of a scientific mission with a dedicated satellite, in order to test and prove the in-space feasibility and the actual usefulness of CAI-based gravity sensors.
In recent years, quantum technology has attracted attention in inertial navigation, especially due to its extreme sensitivity to inertial forces and strong immunity to drifts, which plague conventional sensors. There are multiple groups around the world working on cold atom interferometry aiming to develop high sensitive inertial sensors for very high accuracy autonomous navigation. Recent advancements in micro-fabrication technologies have helped in development of robust and miniaturized atom interferometry based high performance inertial systems. These, in future, will pave way for autonomous satellite inertial navigation sensors based on cold atoms. Here we discuss the achievements towards realizing cold atom inertial sensors and their indomitable role as inertial sensors for future satellites. A detailed survey on the initiatives taken by different space agencies, their achievements and their plans to explore its potential in space are also discussed.
High precision atom interferometers have shown attractive prospects in laboratory for testing fundamental physics and inertial sensing. Efforts on applying this innovative technology to field applications are also being made intensively. As the manipulation of cold atoms and related matching technologies mature, inertial sensors based on atom interferometry can be adapted to various indoor or mobile platforms. A series of experiments have been conducted and high performance has been achieved. In this paper, we will introduce the principles, the key technologies, and the applications of atom interferometers, and mainly review the recent progress of movable atom gravimeters.
Summary form only given. A collaboration between European research groups is developing novel atomic inertial quantum sensors based on matter-wave optics and Raman interferometry. For this purpose we are implementing a gravimeter and a gyroscope using ultra cold atoms as test masses. Inertial quantum sensors could represent a new tool for the precise detection of faint forces and tiny rotations. According to the principle of these sensors, the measured physical quantity will be converted into a frequency, which can be measured with highest accuracy. The items of atom interferometry will range from fundamental physical tests to many practical applications such as: local gravity measurements, allowing a precise underground mapping, and space navigation. In this contest the main goal is to realize modular and portable systems.
Autonomous navigation has become increasingly important for deep-space missions, which cannot use GPS and receive limited, delayed tracking from Earth. Inertial navigation systems, aboard a spacecraft itself, offer an alternative, but they drift as errors accumulate over time. This review assesses whether cold-atom interferometry, a sensor with far lower drift than systems currently in use, could support such navigation. It outlines the physics of atom interferometry, the advantage of operating in the microgravity of space, and demonstrations in spaceflight so far. It then considers what would be required to make the technology practical, such as reducing its size, weight, and power demands. An estimate of position drift shows that, although the cold-atom sensor accumulates far less error than a conventional one, it is unlikely to be able to support multi-year autonomous navigation without periodic external corrections. It would therefore need to be paired with position updates rather than used as a standalone navigation system.