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Sensors, Volume 11, Issue 10 (October 2011), Pages 9121-10009

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Open AccessArticle Collaborative Localization Algorithms for Wireless Sensor Networks with Reduced Localization Error
Sensors 2011, 11(10), 9989-10009; https://doi.org/10.3390/s111009989
Received: 23 August 2011 / Revised: 12 October 2011 / Accepted: 18 October 2011 / Published: 21 October 2011
Cited by 22 | PDF Full-text (2098 KB) | HTML Full-text | XML Full-text
Abstract
Localization is an important research issue in Wireless Sensor Networks (WSNs). Though Global Positioning System (GPS) can be used to locate the position of the sensors, unfortunately it is limited to outdoor applications and is costly and power consuming. In order to find
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Localization is an important research issue in Wireless Sensor Networks (WSNs). Though Global Positioning System (GPS) can be used to locate the position of the sensors, unfortunately it is limited to outdoor applications and is costly and power consuming. In order to find location of sensor nodes without help of GPS, collaboration among nodes is highly essential so that localization can be accomplished efficiently. In this paper, novel localization algorithms are proposed to find out possible location information of the normal nodes in a collaborative manner for an outdoor environment with help of few beacons and anchor nodes. In our localization scheme, at most three beacon nodes should be collaborated to find out the accurate location information of any normal node. Besides, analytical methods are designed to calculate and reduce the localization error using probability distribution function. Performance evaluation of our algorithm shows that there is a trade off betweendeployed number of beacon nodes and localization error, and average localization time of the network can be increased with increase in the number of normal nodes deployed over a region. Full article
(This article belongs to the Special Issue Collaborative Sensors)
Open AccessArticle Application of Terahertz Radiation to Soil Measurements: Initial Results
Sensors 2011, 11(10), 9973-9988; https://doi.org/10.3390/s111009973
Received: 22 August 2011 / Revised: 13 October 2011 / Accepted: 13 October 2011 / Published: 21 October 2011
Cited by 11 | PDF Full-text (5337 KB) | HTML Full-text | XML Full-text
Abstract
Developing soil sensors with the possibility of continuous online measurement is a major challenge in soil science. Terahertz (THz) electromagnetic radiation may provide the opportunity for the measurement of organic material density, water content and other soil parameters at different soil depths. Penetration
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Developing soil sensors with the possibility of continuous online measurement is a major challenge in soil science. Terahertz (THz) electromagnetic radiation may provide the opportunity for the measurement of organic material density, water content and other soil parameters at different soil depths. Penetration depth and information content is important for a functional soil sensor. Therefore, we present initial research on the analysis of absorption coefficients of four different soil samples by means of THz transmission measurements. An optimized soil sample holder to determine absorption coefficients was used. This setup improves data acquisition because interface reflections can be neglected. Frequencies of 340 GHz to 360 GHz and 1.627 THz to 2.523 THz provided information about an existing frequency dependency. The results demonstrate the potential of this THz approach for both soil analysis and imaging of buried objects. Therefore, the THz approach allows different soil samples to be distinguished according to their different absorption properties so that relations among soil parameters may be established in future. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle Enzyme-Polymers Conjugated to Quantum-Dots for Sensing Applications
Sensors 2011, 11(10), 9951-9972; https://doi.org/10.3390/s111009951
Received: 22 September 2011 / Revised: 11 October 2011 / Accepted: 17 October 2011 / Published: 21 October 2011
Cited by 29 | PDF Full-text (1139 KB) | HTML Full-text | XML Full-text
Abstract
In the present research, the concept of developing a novel system based on polymer-enzyme macromolecules was tested by coupling carboxylic acid functionalized poly(vinyl alcohol) (PVA-COOH) to glucose oxidase (GOx) followed by the bioconjugation with CdS quantum-dots (QD). The resulting organic-inorganic nanohybrids were characterized
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In the present research, the concept of developing a novel system based on polymer-enzyme macromolecules was tested by coupling carboxylic acid functionalized poly(vinyl alcohol) (PVA-COOH) to glucose oxidase (GOx) followed by the bioconjugation with CdS quantum-dots (QD). The resulting organic-inorganic nanohybrids were characterized by UV-visible spectroscopy, infrared spectroscopy, Photoluminescence spectroscopy (PL) and transmission electron microscopy (TEM). The spectroscopy results have clearly shown that the polymer-enzyme macromolecules (PVA-COOH/GOx) were synthesized by the proposed zero-length linker route. Moreover, they have performed as successful capping agents for the nucleation and constrained growth of CdS quantum-dots via aqueous colloidal chemistry. The TEM images associated with the optical absorption results have indicated the formation of CdS nanocrystals with estimated diameters of about 3.0 nm. The “blue-shift” in the visible absorption spectra and the PL values have provided strong evidence that the fluorescent CdS nanoparticles were produced in the quantum-size confinement regime. Finally, the hybrid system was biochemically assayed by injecting the glucose substrate and detecting the formation of peroxide with the enzyme horseradish peroxidase (HRP). Thus, the polymer-enzyme-QD hybrid has behaved as a nanostructured sensor for glucose detecting. Full article
(This article belongs to the Special Issue Sensing with Quantum Dots)
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Open AccessArticle In Situ Monitoring of Temperature inside Lithium-Ion Batteries by Flexible Micro Temperature Sensors
Sensors 2011, 11(10), 9942-9950; https://doi.org/10.3390/s111009942
Received: 29 August 2011 / Revised: 18 October 2011 / Accepted: 18 October 2011 / Published: 21 October 2011
Cited by 33 | PDF Full-text (1507 KB) | HTML Full-text | XML Full-text
Abstract
Lithium-ion secondary batteries are commonly used in electric vehicles, smart phones, personal digital assistants (PDA), notebooks and electric cars. These lithium-ion secondary batteries must charge and discharge rapidly, causing the interior temperature to rise quickly, raising a safety issue. Over-charging results in an
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Lithium-ion secondary batteries are commonly used in electric vehicles, smart phones, personal digital assistants (PDA), notebooks and electric cars. These lithium-ion secondary batteries must charge and discharge rapidly, causing the interior temperature to rise quickly, raising a safety issue. Over-charging results in an unstable voltage and current, causing potential safety problems, such as thermal runaways and explosions. Thus, a micro flexible temperature sensor for the in in-situ monitoring of temperature inside a lithium-ion secondary battery must be developed. In this work, flexible micro temperature sensors were integrated into a lithium-ion secondary battery using the micro-electro-mechanical systems (MEMS) process for monitoring temperature in situ. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle Fault Diagnosis for Micro-Gas Turbine Engine Sensors via Wavelet Entropy
Sensors 2011, 11(10), 9928-9941; https://doi.org/10.3390/s111009928
Received: 21 September 2011 / Revised: 13 October 2011 / Accepted: 18 October 2011 / Published: 21 October 2011
Cited by 14 | PDF Full-text (712 KB) | HTML Full-text | XML Full-text
Abstract
Sensor fault diagnosis is necessary to ensure the normal operation of a gas turbine system. However, the existing methods require too many resources and this need can’t be satisfied in some occasions. Since the sensor readings are directly affected by sensor state, sensor
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Sensor fault diagnosis is necessary to ensure the normal operation of a gas turbine system. However, the existing methods require too many resources and this need can’t be satisfied in some occasions. Since the sensor readings are directly affected by sensor state, sensor fault diagnosis can be performed by extracting features of the measured signals. This paper proposes a novel fault diagnosis method for sensors based on wavelet entropy. Based on the wavelet theory, wavelet decomposition is utilized to decompose the signal in different scales. Then the instantaneous wavelet energy entropy (IWEE) and instantaneous wavelet singular entropy (IWSE) are defined based on the previous wavelet entropy theory. Subsequently, a fault diagnosis method for gas turbine sensors is proposed based on the results of a numerically simulated example. Then, experiments on this method are carried out on a real micro gas turbine engine. In the experiment, four types of faults with different magnitudes are presented. The experimental results show that the proposed method for sensor fault diagnosis is efficient. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle Coverage Assessment and Target Tracking in 3D Domains
Sensors 2011, 11(10), 9904-9927; https://doi.org/10.3390/s111009904
Received: 20 August 2011 / Revised: 15 September 2011 / Accepted: 15 September 2011 / Published: 20 October 2011
Cited by 6 | PDF Full-text (11181 KB) | HTML Full-text | XML Full-text
Abstract
Recent advances in integrated electronic devices motivated the use of Wireless Sensor Networks (WSNs) in many applications including domain surveillance and mobile target tracking, where a number of sensors are scattered within a sensitive region to detect the presence of intruders and forward
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Recent advances in integrated electronic devices motivated the use of Wireless Sensor Networks (WSNs) in many applications including domain surveillance and mobile target tracking, where a number of sensors are scattered within a sensitive region to detect the presence of intruders and forward related events to some analysis center(s). Obviously, sensor deployment should guarantee an optimal event detection rate and should reduce coverage holes. Most of the coverage control approaches proposed in the literature deal with two-dimensional zones and do not develop strategies to handle coverage in three-dimensional domains, which is becoming a requirement for many applications including water monitoring, indoor surveillance, and projectile tracking. This paper proposes efficient techniques to detect coverage holes in a 3D domain using a finite set of sensors, repair the holes, and track hostile targets. To this end, we use the concepts of Voronoi tessellation, Vietoris complex, and retract by deformation. We show in particular that, through a set of iterative transformations of the Vietoris complex corresponding to the deployed sensors, the number of coverage holes can be computed with a low complexity. Mobility strategies are also proposed to repair holes by moving appropriately sensors towards the uncovered zones. The tracking objective is to set a non-uniform WSN coverage within the monitored domain to allow detecting the target(s) by the set of sensors. We show, in particular, how the proposed algorithms adapt to cope with obstacles. Simulation experiments are carried out to analyze the efficiency of the proposed models. To our knowledge, repairing and tracking is addressed for the first time in 3D spaces with different sensor coverage schemes. Full article
Open AccessArticle Cooperative MIMO Communication at Wireless Sensor Network: An Error Correcting Code Approach
Sensors 2011, 11(10), 9887-9903; https://doi.org/10.3390/s111009887
Received: 10 September 2011 / Revised: 13 October 2011 / Accepted: 13 October 2011 / Published: 20 October 2011
Cited by 14 | PDF Full-text (209 KB) | HTML Full-text | XML Full-text
Abstract
Cooperative communication in wireless sensor network (WSN) explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN) by exploiting multiple input multiple output (MIMO) and multiple input single output (MISO) configurations. In this paper, an energy efficient cooperative
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Cooperative communication in wireless sensor network (WSN) explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN) by exploiting multiple input multiple output (MIMO) and multiple input single output (MISO) configurations. In this paper, an energy efficient cooperative MIMO (C-MIMO) technique is proposed where low density parity check (LDPC) code is used as an error correcting code. The rate of LDPC code is varied by varying the length of message and parity bits. Simulation results show that the cooperative communication scheme outperforms SISO scheme in the presence of LDPC code. LDPC codes with different code rates are compared using bit error rate (BER) analysis. BER is also analyzed under different Nakagami fading scenario. Energy efficiencies are compared for different targeted probability of bit error pb. It is observed that C-MIMO performs more efficiently when the targeted pb is smaller. Also the lower encoding rate for LDPC code offers better error characteristics. Full article
(This article belongs to the Special Issue Selected Papers from FGIT 2010)
Open AccessArticle Development and Evaluation of a Miniaturized Taste Sensor Chip
Sensors 2011, 11(10), 9878-9886; https://doi.org/10.3390/s111009878
Received: 22 September 2011 / Revised: 17 October 2011 / Accepted: 18 October 2011 / Published: 20 October 2011
Cited by 16 | PDF Full-text (847 KB) | HTML Full-text | XML Full-text
Abstract
A miniaturized taste sensor chip was designed for use in a portable-type taste sensing system. The fabricated sensor chip (40 mm × 26 mm × 2.2 mm) has multiple taste-sensing sites consisting of a poly(hydroxyethyl methacrylate) hydrogel with KCl as the electrolyte layer
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A miniaturized taste sensor chip was designed for use in a portable-type taste sensing system. The fabricated sensor chip (40 mm × 26 mm × 2.2 mm) has multiple taste-sensing sites consisting of a poly(hydroxyethyl methacrylate) hydrogel with KCl as the electrolyte layer for stability of the membrane potential and artificial lipid membranes as the taste sensing elements. The sensor responses to the standard taste substances showed high accuracy and good reproducibility, which is comparable with the performance of the sensor probe of the commercialized taste sensing system. Thus, the fabricated taste sensor chip could be used as a key element for the realization of a portable-type taste sensing system. Full article
(This article belongs to the Special Issue Ultra-Small Sensor Systems and Components)
Open AccessArticle An Approach for Removing Redundant Data from RFID Data Streams
Sensors 2011, 11(10), 9863-9877; https://doi.org/10.3390/s111009863
Received: 26 August 2011 / Revised: 9 October 2011 / Accepted: 17 October 2011 / Published: 20 October 2011
Cited by 20 | PDF Full-text (2128 KB) | HTML Full-text | XML Full-text
Abstract
Radio frequency identification (RFID) systems are emerging as the primary object identification mechanism, especially in supply chain management. However, RFID naturally generates a large amount of duplicate readings. Removing these duplicates from the RFID data stream is paramount as it does not contribute
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Radio frequency identification (RFID) systems are emerging as the primary object identification mechanism, especially in supply chain management. However, RFID naturally generates a large amount of duplicate readings. Removing these duplicates from the RFID data stream is paramount as it does not contribute new information to the system and wastes system resources. Existing approaches to deal with this problem cannot fulfill the real time demands to process the massive RFID data stream. We propose a data filtering approach that efficiently detects and removes duplicate readings from RFID data streams. Experimental results show that the proposed approach offers a significant improvement as compared to the existing approaches. Full article
(This article belongs to the Special Issue Selected Papers from FGIT 2010)
Open AccessArticle A Multi-Sensorial Hybrid Control for Robotic Manipulation in Human-Robot Workspaces
Sensors 2011, 11(10), 9839-9862; https://doi.org/10.3390/s111009839
Received: 3 August 2011 / Revised: 10 October 2011 / Accepted: 17 October 2011 / Published: 20 October 2011
Cited by 5 | PDF Full-text (796 KB) | HTML Full-text | XML Full-text
Abstract
Autonomous manipulation in semi-structured environments where human operators can interact is an increasingly common task in robotic applications. This paper describes an intelligent multi-sensorial approach that solves this issue by providing a multi-robotic platform with a high degree of autonomy and the capability
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Autonomous manipulation in semi-structured environments where human operators can interact is an increasingly common task in robotic applications. This paper describes an intelligent multi-sensorial approach that solves this issue by providing a multi-robotic platform with a high degree of autonomy and the capability to perform complex tasks. The proposed sensorial system is composed of a hybrid visual servo control to efficiently guide the robot towards the object to be manipulated, an inertial motion capture system and an indoor localization system to avoid possible collisions between human operators and robots working in the same workspace, and a tactile sensor algorithm to correctly manipulate the object. The proposed controller employs the whole multi-sensorial system and combines the measurements of each one of the used sensors during two different phases considered in the robot task: a first phase where the robot approaches the object to be grasped, and a second phase of manipulation of the object. In both phases, the unexpected presence of humans is taken into account. This paper also presents the successful results obtained in several experimental setups which verify the validity of the proposed approach. Full article
(This article belongs to the Special Issue Collaborative Sensors)
Open AccessArticle Sonic Anemometry to Measure Natural Ventilation in Greenhouses
Sensors 2011, 11(10), 9820-9838; https://doi.org/10.3390/s111009820
Received: 19 September 2011 / Revised: 14 October 2011 / Accepted: 14 October 2011 / Published: 19 October 2011
Cited by 16 | PDF Full-text (1429 KB) | HTML Full-text | XML Full-text
Abstract
The present work has developed a methodology for studying natural ventilation in Mediterranean greenhouses by means of sonic anemometry. In addition, specific calculation programmes have been designed to enable processing and analysis of the data recorded during the experiments. Sonic anemometry allows us
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The present work has developed a methodology for studying natural ventilation in Mediterranean greenhouses by means of sonic anemometry. In addition, specific calculation programmes have been designed to enable processing and analysis of the data recorded during the experiments. Sonic anemometry allows us to study the direction of the airflow at all the greenhouse vents. Knowing through which vents the air enters and leaves the greenhouse enables us to establish the airflow pattern of the greenhouse under natural ventilation conditions. In the greenhouse analysed in this work for Poniente wind (from the southwest), a roof vent designed to open towards the North (leeward) could allow a positive interaction between the wind and stack effects, improving the ventilation capacity of the greenhouse. The cooling effect produced by the mass of turbulent air oscillating between inside and outside the greenhouse at the side vents was limited to 2% (for high wind speed, uo ≥ 4 m s−1) reaching 36.3% when wind speed was lower (uo = 2 m s−1). Full article
(This article belongs to the Section Physical Sensors)
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Open AccessArticle Support Loss and Q Factor Enhancement for a Rocking Mass Microgyroscope
Sensors 2011, 11(10), 9807-9819; https://doi.org/10.3390/s111009807
Received: 15 September 2011 / Revised: 10 October 2011 / Accepted: 17 October 2011 / Published: 19 October 2011
Cited by 4 | PDF Full-text (834 KB) | HTML Full-text | XML Full-text
Abstract
A rocking mass gyroscope (RMG) is a kind of vibrating mass gyroscope with high sensitivity, whose driving mode and sensing mode are completely uniform. MEMS RMG devices are a research hotspot now because they have the potential to be used in space applications.
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A rocking mass gyroscope (RMG) is a kind of vibrating mass gyroscope with high sensitivity, whose driving mode and sensing mode are completely uniform. MEMS RMG devices are a research hotspot now because they have the potential to be used in space applications. Support loss is the dominant energy loss mechanism influencing their high sensitivity. An accurate analytical model of support loss for RMGs is presented to enhance their Q factors. The anchor type and support loss mechanism of an RMG are analyzed. Firstly, the support loads, powers flowing into support structure, and vibration energy of an RMG are all developed. Then the analytical model of support loss for the RMG is developed, and its sensitivities to the main structural parameters are also analyzed. High-Q design guidelines for rocking mass microgyroscopes are deduced. Finally, the analytical model is validated by the experimental data and the data from the existing literature. The thicknesses of the prototypes are reduced from 240 µm to 60 µm, while Q factors increase from less than 150 to more than 800. The derived model is general and applicable to various beam resonators, providing significant insight to the design of high-Q MEMS devices. Full article
(This article belongs to the Section Physical Sensors)
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Open AccessArticle Manufacture and Characterization of High Q-Factor Inductors Based on CMOS-MEMS Techniques
Sensors 2011, 11(10), 9798-9806; https://doi.org/10.3390/s111009798
Received: 22 August 2011 / Revised: 12 October 2011 / Accepted: 17 October 2011 / Published: 19 October 2011
Cited by 3 | PDF Full-text (885 KB) | HTML Full-text | XML Full-text
Abstract
A high Q-factor (quality-factor) spiral inductor fabricated by the CMOS (complementary metal oxide semiconductor) process and a post-process was investigated. The spiral inductor is manufactured on a silicon substrate. A post-process is used to remove the underlying silicon substrate in order to reduce
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A high Q-factor (quality-factor) spiral inductor fabricated by the CMOS (complementary metal oxide semiconductor) process and a post-process was investigated. The spiral inductor is manufactured on a silicon substrate. A post-process is used to remove the underlying silicon substrate in order to reduce the substrate loss and to enhance the Q-factor of the inductor. The post-process adopts RIE (reactive ion etching) to etch the sacrificial oxide layer, and then TMAH (tetramethylammonium hydroxide) is employed to remove the silicon substrate for obtaining the suspended spiral inductor. The advantage of this post-processing method is its compatibility with the CMOS process. The performance of the spiral inductor is measured by an Agilent 8510C network analyzer and a Cascade probe station. Experimental results show that the Q-factor and inductance of the spiral inductor are 15 at 15 GHz and 1.8 nH at 1 GHz, respectively. Full article
(This article belongs to the Special Issue Modeling, Testing and Reliability Issues in MEMS Engineering 2011)
Open AccessReview Local Positioning Systems in (Game) Sports
Sensors 2011, 11(10), 9778-9797; https://doi.org/10.3390/s111009778
Received: 12 August 2011 / Revised: 11 October 2011 / Accepted: 17 October 2011 / Published: 19 October 2011
Cited by 28 | PDF Full-text (552 KB) | HTML Full-text | XML Full-text
Abstract
Position data of players and athletes are widely used in sports performance analysis for measuring the amounts of physical activities as well as for tactical assessments in game sports. However, positioning sensing systems are applied in sports as tools to gain objective information
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Position data of players and athletes are widely used in sports performance analysis for measuring the amounts of physical activities as well as for tactical assessments in game sports. However, positioning sensing systems are applied in sports as tools to gain objective information of sports behavior rather than as components of intelligent spaces (IS). The paper outlines the idea of IS for the sports context with special focus to game sports and how intelligent sports feedback systems can benefit from IS. Henceforth, the most common location sensing techniques used in sports and their practical application are reviewed, as location is among the most important enabling techniques for IS. Furthermore, the article exemplifies the idea of IS in sports on two applications. Full article
(This article belongs to the Special Issue Sensorial Systems Applied to Intelligent Spaces)
Open AccessArticle Investigation of Digital Sun Sensor Technology with an N-Shaped Slit Mask
Sensors 2011, 11(10), 9764-9777; https://doi.org/10.3390/s111009764
Received: 6 August 2011 / Revised: 27 September 2011 / Accepted: 17 October 2011 / Published: 18 October 2011
Cited by 17 | PDF Full-text (965 KB) | HTML Full-text | XML Full-text
Abstract
Nowadays sun sensors are being more widely used in satellites to determine the sunray orientation, thus development of a new version of sun sensor with lighter mass, lower power consumption and smaller size it of considerable interest. This paper introduces such a novel
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Nowadays sun sensors are being more widely used in satellites to determine the sunray orientation, thus development of a new version of sun sensor with lighter mass, lower power consumption and smaller size it of considerable interest. This paper introduces such a novel digital sun sensor, which is composed of a micro-electro-mechanical system (MEMS) mask with an N-shaped slit as well as a single linear array charge-coupled device (CCD). The sun sensor can achieve the measurement of two-axis sunray angles according to the three sun spot images on the CCD formed by sun light illumination through the mask. Given the CCD glass layer, an iterative algorithm is established to correct the refraction error. Thus, system resolution, update rate and other characteristics are improved based on the model simulation and system design. The test of sun sensor prototype is carried out on a three-axis rotating platform with a sun simulator. The test results show that the field of view (FOV) is ±60° × ±60° and the accuracy is 0.08 degrees of arc (3σ) in the whole FOV. Since the power consumption of the prototype is only 300 mW and the update rate is 14 Hz, the novel digital sun sensor can be applied broadly in micro/nano-satellites, even pico-satellites. Full article
(This article belongs to the Section Physical Sensors)
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