Quantum technology have attracted strong interest in recent years thanks to its extreme sensitivity to inertial forces and its strong immunity to drifts compared to conventional mechanical sensors. This paper introduces cold atom sensors as six-axis inertial sensors from the engineering point of view. In order to highlight the potential of this technology as needed for inertial navigation, a strapdown closed-loop-simulation has been developed. Furthermore, we present an error model for quantum sensors that includes terms such as quantum shot noise and phase noise of the reference laser. Considering this inherent stochastic characteristics, we made also a comparison with other conventional inertial measurement units. The analysis shows that quantum sensors with the same sensitivity as of for static measuring local gravity can determine their position with accuracy of one-meter level even after one hour, while other quantum sensors with less sensitivity exhibit for the same duration an amplitude up to 1 km, similar to conventional sensors.
Quantum technology have attracted strong interest in recent years thanks to its extreme sensitivity to inertial forces and its strong immunity to drifts compared to conventional mechanical sensors. This paper introduces cold atom sensors as six-axis inertial sensors from the engineering point of view. In order to highlight the potential of this technology as needed for inertial navigation, a strapdown closed-loop-simulation has been developed. Furthermore, we present an error model for quantum sensors that includes terms such as quantum shot noise and phase noise of the reference laser. Considering this inherent stochastic characteristics, we made also a comparison with other conventional inertial measurement units. The analysis shows that quantum sensors with the same sensitivity as of for static measuring local gravity can determine their position with accuracy of one-meter level even after one hour, while other quantum sensors with less sensitivity exhibit for the same duration an amplitude up to 1 km, similar to conventional 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.
Inertial sensors based on cold atom interferometry exhibit many interesting features for applications related to inertial navigation, particularly in terms of sensitivity and long-term stability. However, at present the typical atom interferometer is still very much an experiment—consisting of a bulky, static apparatus with a limited dynamic range and high sensitivity to environmental effects. To be compliant with mobile applications further development is needed. In this work, we present a compact and mobile experiment, which we recently used to achieve the first inertial measurements with an atomic accelerometer onboard an aircraft. By integrating classical inertial sensors into our apparatus, we are able to operate the atomic sensor well beyond its standard operating range, corresponding to half of an interference fringe. We report atom-based acceleration measurements along both the horizontal and vertical axes of the aircraft with one-shot sensitivities of 2.3 × 10−4 g over a range of ∼ 0.1 g. The same technology can be used to develop cold-atom gyroscopes, which could surpass the best optical gyroscopes in terms of long-term sensitivity. Our apparatus was also designed to study multi-axis atom interferometry with the goal of realizing a full inertial measurement unit comprised of the three axes of acceleration and rotation. Finally, we present a compact and tunable laser system, which constitutes an essential part of any cold-atom-based sensor. The architecture of the laser is based on phase modulating a single fiber-optic laser diode, and can be tuned over a range of 1 GHz in less than 200 μs.
Inertial sensors based on cold atoms and light-pulse interferometry exhibit state-of-the-art sensitivity and ultra-low measurement bias that could revolutionize a variety of fields including geophysics and seismology, gravitational wave detection and fundamental tests of gravity, and inertial navigation. In the latter case, cold-atom interferometers are widely considered as breakthrough technology for future autonomous INSs. Nowadays, absolute quantum inertial sensors are available as commercial and field-deployable devices. Yet, their current size and complexity has not yet reached a technology readiness level compatible with mobile applications or plug-and-play operation by non-specialists. These systems are in desperate need of further development and miniaturization. We will present progress beyond these first experiments while exploring new methods relying on 3D matter-wave manipulation that can lead to interferometer geometries that are simultaneously sensitive to accelerations and rotations in 3D and can discern their vector components within a single measurement. These novel innovations produce additional sensitivity to rotations and gravity gradients which has not yet been exploited experimentally and could be a game changing innovation for future atomic sensors. The ability to measure the full acceleration and rotation vectors with a compact, high-precision, low-bias inertial sensor could strongly impact the fields of inertial navigation, gravity gradiometry, and gyroscopy.
Positioning currently relies heavily on Global Navigation Satellite Systems (GNSS). Combined with classical accelerometers and gyroscopes, precise determination of orientation and position at any given time become available. However, but the availability of GNSS (e.g. GPS) is limited and not guaranteed at all times.In this paper we present an alternative based on atom interferometry using cold atom ensembles. An inertial sensor based on cold atoms allows, in theory, for nearly drift-free measurements of inertial forces with accuracies unreached by classical sensors, but the technology is still locked away in large physics laboratories [1].This paper introduces a compact device called SECAMP, which is capable of cooling atoms down to μ-Kelvin. SECAMP has the potential to measure inertial acceleration in three degrees of freedom. In the following, we present the current experimental setup of the apparatus and outline the next steps for the inertial sensor.
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.
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.