Knut Ola Dølven, Juha Vierinen, Roberto Grilli, Jack Triest, Bénédicte Ferré
Accurate high-resolution measurements are essential to improve our understanding of environmental processes. Several chemical sensors relying on membrane separation extraction techniques have slow response times due to a dependence on equilibrium partitioning across the membrane separating the measured medium (i.e., a measuring chamber) and the medium of interest (i.e., a solvent). We present a new technique for deconvolving slow-sensor-response signals using statistical inverse theory; applying a weighted linear least-squares estimator with the growth law as a measurement model. The solution is regularized using model sparsity, assuming changes in the measured quantity occur with a certain time step, which can be selected based on domain-specific knowledge or L-curve analysis. The advantage of this method is that it (1) models error propagation, providing an explicit uncertainty estimate of the response-time-corrected signal; (2) enables evaluation of the solution self consistency; and (3) only requires instrument accuracy, response time, and data as input parameters. Functionality of the technique is demonstrated using simulated, laboratory, and field measurements. In the field experiment, the coefficient of determination (R2) of a slow-response methane sensor in comparison with an alternative fast-response sensor significantly improved from 0.18 to 0.91 after signal deconvolution. This shows how the proposed method can open up a considerably wider set of applications for sensors and methods suffering from slow response times due to a reliance on the efficacy of diffusion processes.
{"title":"Response time correction of slow-response sensor data by deconvolution of the growth-law equation","authors":"Knut Ola Dølven, Juha Vierinen, Roberto Grilli, Jack Triest, Bénédicte Ferré","doi":"10.5194/gi-11-293-2022","DOIUrl":"https://doi.org/10.5194/gi-11-293-2022","url":null,"abstract":"Accurate high-resolution measurements are essential to improve our understanding of environmental processes. Several chemical sensors relying on membrane separation extraction techniques have slow response times due to a dependence on equilibrium partitioning across the membrane separating the measured medium (i.e., a measuring chamber) and the medium of interest (i.e., a solvent). We present a new technique for deconvolving slow-sensor-response signals using statistical inverse theory; applying a weighted linear least-squares estimator with the growth law as a measurement model.\u0000The solution is regularized using model sparsity, assuming changes in the measured quantity occur with a certain time step, which can be selected based on domain-specific knowledge or L-curve analysis. The advantage of this method is that it (1) models error propagation, providing an explicit uncertainty estimate of the response-time-corrected signal; (2) enables evaluation of the solution self consistency; and (3) only requires instrument accuracy, response time, and data as input parameters. Functionality of the technique is demonstrated using simulated, laboratory, and field measurements. In the field experiment, the coefficient of determination (<span><i>R</i><sup>2</sup></span>) of a slow-response methane sensor in comparison with an alternative fast-response sensor significantly improved from 0.18 to 0.91 after signal deconvolution. This shows how the proposed method can open up a considerably wider set of applications for sensors and methods suffering from slow response times due to a reliance on the efficacy of diffusion processes.","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138505394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Climate science depends upon accurate measurements of air temperature and humidity, the majority of which are still derived from sensors exposed within passively ventilated louvred Stevenson-type thermometer screens. It is well-documented that, under certain circumstances, air temperatures measured within such screens can differ significantly from “true” air temperatures measured by other methods, such as aspirated sensors. Passively ventilated screens depend upon wind motion to provide ventilation within the screen and thus airflow over the sensors contained therein. Consequently, instances of anomalous temperatures occur most often during light winds when airflow through the screen is weakest, particularly when in combination with strong or low-angle incident solar radiation. Adequate ventilation is essential for reliable and consistent measurements of both air temperature and humidity, yet very few systematic comparisons to quantify relationships between external wind speed and airflow within a thermometer screen have been made. This paper addresses that gap by summarizing the results of a 3-month field experiment in which airflow within a UK-standard Stevenson screen was measured using a sensitive sonic anemometer and comparisons made with simultaneous wind speed and direction records from the same site. The mean in-screen ventilation rate was found to be 0.2 m s−1 (median 0.18 m s−1), well below the 1 m s−1 minimum assumed in meteorological and design standard references, and only about 7 % of the scalar mean wind speed at 10 m. The implications of low in-screen ventilation on the uncertainty of air temperature and humidity measurements from Stevenson-type thermometer screens are discussed, particularly those due to the differing response times of dry- and wet-bulb temperature sensors and ambiguity in the value of the psychrometric coefficient.
摘要气候科学依赖于对空气温度和湿度的精确测量，其中大部分仍然来自暴露在被动通风百叶窗史蒂文森式温度计屏幕中的传感器。有充分的证据表明，在某些情况下，在这种屏幕内测量的空气温度可能与通过其他方法（如吸气传感器）测量的“真实”空气温度存在显著差异。被动通风的屏幕取决于风的运动，以在屏幕内提供通风，从而在其中包含的传感器上提供气流。因此，当穿过屏幕的气流最弱时，特别是当与强或低角度入射的太阳辐射结合时，在微风中最常发生异常温度的情况。充分的测量对于可靠和一致地测量空气温度和湿度至关重要，但很少有系统的比较来量化外部风速和温度计屏幕内气流之间的关系。本文通过总结一项为期3个月的现场实验的结果来解决这一差距，在该实验中，使用灵敏的声波动量计测量了英国标准史蒂文森屏幕内的气流，并将其与来自同一地点的同时风速和风向记录进行了比较。筛内平均通气率为0.2 m s−1（中位数0.18 m s−1），远低于1 m 气象和设计标准参考中假设的s−1最小值，仅约为7 % 10时的标量平均风速 m.讨论了低屏通风对Stevenson型温度计屏的空气温度和湿度测量不确定度的影响，特别是由于干球温度传感器和湿球温度传感器的响应时间不同以及湿度系数值的模糊性造成的影响。
{"title":"Measurements of natural airflow within a Stevenson screen and its influence on air temperature and humidity records","authors":"S. Burt","doi":"10.5194/gi-11-263-2022","DOIUrl":"https://doi.org/10.5194/gi-11-263-2022","url":null,"abstract":"Abstract. Climate science depends upon accurate measurements of air temperature and\u0000humidity, the majority of which are still derived from sensors exposed\u0000within passively ventilated louvred Stevenson-type thermometer screens. It\u0000is well-documented that, under certain circumstances, air temperatures\u0000measured within such screens can differ significantly from “true” air\u0000temperatures measured by other methods, such as aspirated sensors.\u0000Passively ventilated screens depend upon wind motion to provide ventilation\u0000within the screen and thus airflow over the sensors contained therein.\u0000Consequently, instances of anomalous temperatures occur most often during\u0000light winds when airflow through the screen is weakest, particularly when in\u0000combination with strong or low-angle incident solar radiation. Adequate\u0000ventilation is essential for reliable and consistent measurements of both\u0000air temperature and humidity, yet very few systematic comparisons to\u0000quantify relationships between external wind speed and airflow within a\u0000thermometer screen have been made. This paper addresses that gap by\u0000summarizing the results of a 3-month field experiment in which airflow\u0000within a UK-standard Stevenson screen was measured using a sensitive sonic\u0000anemometer and comparisons made with simultaneous wind speed and direction\u0000records from the same site. The mean in-screen ventilation rate was found to\u0000be 0.2 m s−1 (median 0.18 m s−1), well below the 1 m s−1\u0000minimum assumed in meteorological and design standard references, and only\u0000about 7 % of the scalar mean wind speed at 10 m. The implications of low\u0000in-screen ventilation on the uncertainty of air temperature and humidity\u0000measurements from Stevenson-type thermometer screens are discussed,\u0000particularly those due to the differing response times of dry- and wet-bulb\u0000temperature sensors and ambiguity in the value of the psychrometric\u0000coefficient.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49441498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Wilson, Jacob L. Conrad, John Anderson, A. Swidinsky, J. Shragge
Abstract. Recent advancements and the widespread availability of low-cost microcontrollers and electronic components have created new opportunities for developing and using low-cost, open-source instrumentation for near-surface geophysical investigations. Geophysical methods that do not require ground contact, such as frequency-domain electromagnetics, allow one or two users to quickly acquire significant amounts of ground resistivity data in a cost-effective manner. The Colorado School of Mines electromagnetic system (CSM-EM) is a proof-of-concept instrument capable of sensing conductive objects in near-surface environments, and is similar in concept to commercial-grade equipment while costing under USD 400 to build. We tested the functionality of the CSM-EM system in a controlled laboratory setting during the design phase and validated it over a conductive target in an outdoor environment. The transmitter antenna can generate a current of over 2.5 A, and emit signals that are detectable by a receiver antenna at offsets of up to 25 m. The system requires minor refitting to change the functioning frequency, and has been operationally validated at 0.4 and 1.6 kHz. The receiver signal can be measured by off-the-shelf digital multimeters. Future directions will focus on improving the electronic and mechanical stability of the CSM-EM with the goal of using acquired data to make quantitative measurements of subsurface resistivity.
{"title":"Developing a low-cost frequency-domain electromagnetic induction instrument","authors":"G. Wilson, Jacob L. Conrad, John Anderson, A. Swidinsky, J. Shragge","doi":"10.5194/gi-11-279-2022","DOIUrl":"https://doi.org/10.5194/gi-11-279-2022","url":null,"abstract":"Abstract. Recent advancements and the widespread availability of low-cost microcontrollers and electronic components have created new opportunities for developing and using low-cost, open-source instrumentation for near-surface geophysical investigations. Geophysical methods that do not require ground contact, such as frequency-domain electromagnetics, allow one or two users to quickly acquire significant amounts of ground resistivity data in a cost-effective manner. The Colorado School of Mines electromagnetic system (CSM-EM) is a proof-of-concept instrument capable of sensing conductive objects in near-surface environments, and is similar in concept to commercial-grade equipment while costing under USD 400 to build. We tested the functionality of the CSM-EM system in a controlled laboratory setting during the design phase and validated it over a conductive target in an outdoor environment. The transmitter antenna can generate a current of over 2.5 A, and emit signals that are detectable by a receiver antenna at offsets of up to 25 m. The system requires minor refitting to change the functioning frequency, and has been operationally validated at 0.4 and 1.6 kHz. The receiver signal can be measured by off-the-shelf digital multimeters. Future directions will focus on improving the electronic and mechanical stability of the CSM-EM with the goal of using acquired data to make quantitative measurements of subsurface resistivity.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45265124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Goelles, Tobias Hammer, S. Muckenhuber, Birgit Schlager, J. Abermann, Christian Bauer, Víctor J. Expósito Jiménez, W. Schöner, Markus Schratter, Benjamin Schrei, Kim Senger
Abstract. We propose a newly developed modular MObile LIdar SENsor System (MOLISENS) to enable new applications for small industrial lidar (light detection and ranging) sensors. The stand-alone modular setup supports both monitoring of dynamic processes and mobile mapping applications based on SLAM (Simultaneous Localization and Mapping) algorithms. The main objective of MOLISENS is to exploit newly emerging perception sensor technologies developed for the automotive industry for geoscientific applications. However, MOLISENS can also be used for other application areas, such as 3D mapping of buildings or vehicle-independent data collection for sensor performance assessment and sensor modeling. Compared to TLSs, small industrial lidar sensors provide advantages in terms of size (on the order of 10 cm), weight (on the order of 1 kg or less), price (typically between EUR 5000 and 10 000), robustness (typical protection class of IP68), frame rates (typically 10–20 Hz), and eye safety class (typically 1). For these reasons, small industrial lidar systems can provide a very useful complement to currently used TLS (terrestrial laser scanner) systems that have their strengths in range and accuracy performance. The MOLISENS hardware setup consists of a sensor unit, a data logger, and a battery pack to support stand-alone and mobile applications. The sensor unit includes the small industrial lidar Ouster OS1-64 Gen1, a ublox multi-band active GNSS (Global Navigation Satellite System) with the possibility for RTK (real-time kinematic), and a nine-axis Xsens IMU (inertial measurement unit). Special emphasis was put on the robustness of the individual components of MOLISENS to support operations in rough field and adverse weather conditions. The sensor unit has a standard tripod thread for easy mounting on various platforms. The current setup of MOLISENS has a horizontal field of view of 360∘, a vertical field of view with a 45∘ opening angle, a range of 120 m, a spatial resolution of a few centimeters, and a temporal resolution of 10–20 Hz. To evaluate the performance of MOLISENS, we present a comparison between the integrated small industrial lidar Ouster OS1-64 and the state-of-the-art high-accuracy and high-precision TLS Riegl VZ-6000 in a set of controlled experimental setups. We then apply the small industrial lidar Ouster OS1-64 in several real-world settings. The mobile mapping application of MOLISENS has been tested under various conditions, and results are shown from two surveys in the Lurgrotte cave system in Austria and a glacier cave in Longyearbreen on Svalbard.
{"title":"MOLISENS: MObile LIdar SENsor System to exploit the potential of small industrial lidar devices for geoscientific applications","authors":"T. Goelles, Tobias Hammer, S. Muckenhuber, Birgit Schlager, J. Abermann, Christian Bauer, Víctor J. Expósito Jiménez, W. Schöner, Markus Schratter, Benjamin Schrei, Kim Senger","doi":"10.5194/gi-11-247-2022","DOIUrl":"https://doi.org/10.5194/gi-11-247-2022","url":null,"abstract":"Abstract. We propose a newly developed modular MObile LIdar SENsor System (MOLISENS) to enable new applications for small industrial lidar (light detection and ranging) sensors. The stand-alone modular setup supports both monitoring of dynamic processes and mobile mapping applications based on SLAM (Simultaneous Localization and Mapping) algorithms. The main objective of MOLISENS is to exploit newly emerging perception sensor technologies developed for the automotive industry for geoscientific applications. However, MOLISENS can also be used for other application areas, such as 3D mapping of buildings or vehicle-independent data collection for sensor performance assessment and sensor modeling. Compared to TLSs, small industrial lidar sensors provide advantages in terms of size (on the order of 10 cm), weight (on the order of 1 kg or less), price (typically between EUR 5000 and 10 000), robustness (typical protection class of IP68), frame rates (typically 10–20 Hz), and eye safety class (typically 1). For these reasons, small industrial lidar systems can provide a very useful complement to currently used TLS (terrestrial laser scanner) systems that have their strengths in range and accuracy performance. The MOLISENS hardware setup consists of a sensor unit, a data logger, and a battery pack to support stand-alone and mobile applications. The sensor unit includes the small industrial lidar Ouster OS1-64 Gen1, a ublox multi-band active GNSS (Global Navigation Satellite System) with the possibility for RTK (real-time kinematic), and a nine-axis Xsens IMU (inertial measurement unit). Special emphasis was put on the robustness of the individual components of MOLISENS to support operations in rough field and adverse weather conditions. The sensor unit has a standard tripod thread for easy mounting on various platforms. The current setup of MOLISENS has a horizontal field of view of 360∘, a vertical field of view with a 45∘ opening angle, a range of 120 m, a spatial resolution of a few centimeters, and a temporal resolution of 10–20 Hz. To evaluate the performance of MOLISENS, we present a comparison between the integrated small industrial lidar Ouster OS1-64 and the state-of-the-art high-accuracy and high-precision TLS Riegl VZ-6000 in a set of controlled experimental setups. We then apply the small industrial lidar Ouster OS1-64 in several real-world settings. The mobile mapping application of MOLISENS has been tested under various conditions, and results are shown from two surveys in the Lurgrotte cave system in Austria and a glacier cave in Longyearbreen on Svalbard.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49001342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Passive seismic measurements allow the study of the deeper Earth beneath the thick Antarctic ice sheet cover. Due to logistical and weather constraints, only a fraction of the area of the Antarctic ice sheet can be surveyed with long-term or temporary sensors. A fundamental limitation is the power supply and operation of the instruments during the polar winter. In addition, there is only a limited time window during the field seasons to deploy the stations over the year. Here we present a rapidly and simple deployable self-sufficient mobile seismic station concept. The station consists of different energy supply modules aligned according to the survey needs, measuring duration, and survey aim. Parts of the concept are integrated into an already existing pool of mobile stations and in the seismological network of the geophysical observatory at Neumayer III Station. Other concepts and features are still under development. The overall goal is to use these temporary mobile arrays in regions where little is known about local and regional tectonic earthquake activity.
{"title":"Towards a self-sufficient mobile broadband seismological recording system for year-round operation in Antarctica","authors":"A. Eckstaller, J. Asseng, E. Lippmann, S. Franke","doi":"10.5194/gi-11-235-2022","DOIUrl":"https://doi.org/10.5194/gi-11-235-2022","url":null,"abstract":"Abstract. Passive seismic measurements allow the study of the deeper Earth\u0000beneath the thick Antarctic ice sheet cover. Due to logistical and weather\u0000constraints, only a fraction of the area of the Antarctic ice sheet can be\u0000surveyed with long-term or temporary sensors. A fundamental limitation is\u0000the power supply and operation of the instruments during the polar winter.\u0000In addition, there is only a limited time window during the field seasons to\u0000deploy the stations over the year. Here we present a rapidly and simple\u0000deployable self-sufficient mobile seismic station concept. The station\u0000consists of different energy supply modules aligned according to the survey\u0000needs, measuring duration, and survey aim. Parts of the concept are\u0000integrated into an already existing pool of mobile stations and in\u0000the seismological network of the geophysical observatory at Neumayer III\u0000Station. Other concepts and features are still under development. The\u0000overall goal is to use these temporary mobile arrays in regions where little\u0000is known about local and regional tectonic earthquake activity.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47347324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. The results of a destructive single-event effect susceptibility radiation test of the PNI RM3100 magnetometer sensor, specifically the MagI2C ASIC (application-specific integrated circuit) on the sensor board are presented. The sensor is a low-resource commercial off-the-shelf (COTS) magneto-inductive magnetometer. The device was monitored for destructive events and functional interruptions during exposure to a heavy ion beam at the Lawrence Berkeley National Laboratory's 88′′ Cyclotron. The RM3100 did not experience any destructive single-event effects when irradiated to a total fluence of 1.4 × 107 cm−2 at an effective linear energy transfer (LET) of 76.7 MeV cm2 mg−1 while operated at nominal voltage (3.3 V) and elevated temperature (85 ∘C). When these results are combined with previous total ionizing dose tests showing no failures up to 150 kRad (Si), we conclude that the PNI RM3100 is extremely radiation tolerant and can be used in a variety of space environments.
{"title":"Single-event effect testing of the PNI RM3100 magnetometer for space applications","authors":"M. Moldwin, E. Wilcox, E. Zesta, T. Bonalsky","doi":"10.5194/gi-11-219-2022","DOIUrl":"https://doi.org/10.5194/gi-11-219-2022","url":null,"abstract":"Abstract. The results of a destructive single-event effect susceptibility\u0000radiation test of the PNI RM3100 magnetometer sensor, specifically the\u0000MagI2C ASIC (application-specific integrated circuit) on the sensor\u0000board are presented. The sensor is a low-resource commercial off-the-shelf\u0000(COTS) magneto-inductive magnetometer. The device was monitored for\u0000destructive events and functional interruptions during exposure to a heavy\u0000ion beam at the Lawrence Berkeley National Laboratory's 88′′ Cyclotron. The\u0000RM3100 did not experience any destructive single-event effects when\u0000irradiated to a total fluence of 1.4 × 107 cm−2 at an effective\u0000linear energy transfer (LET) of 76.7 MeV cm2 mg−1 while operated at\u0000nominal voltage (3.3 V) and elevated temperature (85 ∘C). When\u0000these results are combined with previous total ionizing dose tests showing\u0000no failures up to 150 kRad (Si), we conclude that the PNI RM3100 is extremely\u0000radiation tolerant and can be used in a variety of space environments.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41899341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Soil evaporation concerns water and our life support sources, which are important for agriculture or for climate change prediction science. A simple instrument based on the nonsteady-state (NSS) technique for soil evaporation measurement appears suitable. However, because the NSS chamber technique is highly invasive, special care should be provided to correct the wind speed influence on the evaporation process. Soil evaporation is a complex process that involves many soil and air characteristics. Measurement chamber installation on the soil and its head deployment may perturb these characteristics. We therefore had to minimize differences or to correct the measurements. Most of the differences between bare soil and soil with a deployed chamber head can be minimized, except for the wind speed influences that are not reproducible inside a chamber head. Meanwhile, as the wind influences depend on numerous variables that are not monitorable in real time, a self-calibrating chamber with a corresponding protocol called the Autocalibrated Soil Evapo-respiration Chamber (ASERC) was developed to make the measurements easily corrigible on bare soil with a unique variable (wind speed, WS), regardless of the soil composition, soil texture, and other soil or air meteorological variables. A simple protocol followed by this chamber allows us to determine the soil evaporation wind speed susceptibility (Z) and to correct the measurements achieving 0.95 as the coefficient of determination. Some interesting findings on sandy and clayey soil evaporation measured during laboratory calibration and “slow” sensor simulation will also be reported in the two appendices.
{"title":"Wind speed influences corrected Autocalibrated Soil Evapo-respiration Chamber (ASERC) evaporation measures","authors":"B. Zawilski","doi":"10.5194/gi-11-163-2022","DOIUrl":"https://doi.org/10.5194/gi-11-163-2022","url":null,"abstract":"Abstract. Soil evaporation concerns water and our life support sources, which are important for agriculture or for climate change prediction science.\u0000A simple instrument based on the nonsteady-state (NSS) technique for soil\u0000evaporation measurement appears suitable. However, because the NSS chamber\u0000technique is highly invasive, special care should be provided to correct the\u0000wind speed influence on the evaporation process. Soil evaporation is a\u0000complex process that involves many soil and air characteristics. Measurement\u0000chamber installation on the soil and its head deployment may perturb these\u0000characteristics. We therefore had to minimize differences or to correct the\u0000measurements. Most of the differences between bare soil and soil with a\u0000deployed chamber head can be minimized, except for the wind speed influences\u0000that are not reproducible inside a chamber head. Meanwhile, as the wind\u0000influences depend on numerous variables that are not monitorable in real time, a self-calibrating chamber with a\u0000corresponding protocol called the Autocalibrated Soil Evapo-respiration\u0000Chamber (ASERC) was developed to\u0000make the measurements easily corrigible on bare soil with a unique variable (wind speed, WS), regardless of the soil composition, soil texture, and other\u0000soil or air meteorological variables. A simple protocol followed by this chamber\u0000allows us to determine the soil evaporation wind speed susceptibility (Z)\u0000and to correct the measurements achieving 0.95 as the coefficient of\u0000determination. Some interesting findings on sandy and clayey soil\u0000evaporation measured during laboratory calibration and “slow” sensor\u0000simulation will also be reported in the two appendices.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47274323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Catapano, S. Buchert, E. Qamili, T. Nilsson, J. Bouffard, C. Siemes, I. Coco, R. D’Amicis, L. Tøffner-Clausen, L. Trenchi, Poul Erik Holmdahl Olsen, A. Strømme
Abstract. Swarm is the European Space Agency (ESA)'s first Earth observation constellation mission, which was launched in 2013 to study the geomagnetic field and its temporal evolution. Two Langmuir probes aboard each of the three Swarm satellites provide in situ measurements of plasma parameters, which contribute to the study of the ionospheric plasma dynamics. To maintain a high data quality for scientific and technical applications, the Swarm products are continuously monitored and validated via science-oriented diagnostics. This paper presents an overview of the data quality of the Swarm Langmuir probes' measurements. The data quality is assessed by analysing short and long data segments, where the latter are selected to be sufficiently long enough to consider the impact of the solar activity. Langmuir probe data have been validated through comparison with numerical models, other satellite missions, and ground observations. Based on the outcomes from quality control and validation activities conducted by ESA, as well as scientific analysis and feedback provided by the user community, the Swarm products are regularly upgraded. In this paper, we discuss the data quality improvements introduced with the latest baseline, and how the data quality is influenced by the solar cycle. In particular, plasma measurements are more accurate in day-side regions during high solar activity, while electron temperature measurements are more reliable during night side at middle and low latitudes during low solar activity. The main anomalies affecting the Langmuir probe measurements are described, as well as possible improvements in the derived plasma parameters to be implemented in future baselines.
{"title":"Swarm Langmuir probes' data quality validation and future improvements","authors":"F. Catapano, S. Buchert, E. Qamili, T. Nilsson, J. Bouffard, C. Siemes, I. Coco, R. D’Amicis, L. Tøffner-Clausen, L. Trenchi, Poul Erik Holmdahl Olsen, A. Strømme","doi":"10.5194/gi-11-149-2022","DOIUrl":"https://doi.org/10.5194/gi-11-149-2022","url":null,"abstract":"Abstract. Swarm is the European Space Agency (ESA)'s first Earth observation constellation mission, which was launched in 2013 to study the geomagnetic field and its temporal\u0000evolution. Two Langmuir probes aboard each of the three Swarm satellites provide in situ measurements of plasma parameters, which contribute to\u0000the study of the ionospheric plasma dynamics. To maintain a high data quality for scientific and technical applications, the Swarm products are\u0000continuously monitored and validated via science-oriented diagnostics. This paper presents an overview of the data quality of the Swarm Langmuir\u0000probes' measurements. The data quality is assessed by analysing short and long data segments, where the latter are selected to be sufficiently long enough to\u0000consider the impact of the solar activity. Langmuir probe data have been validated through comparison with numerical models, other satellite\u0000missions, and ground observations. Based on the outcomes from quality control and validation activities conducted by ESA, as well as scientific\u0000analysis and feedback provided by the user community, the Swarm products are regularly upgraded. In this paper, we discuss the data quality\u0000improvements introduced with the latest baseline, and how the data quality is influenced by the solar cycle. In particular, plasma measurements are\u0000more accurate in day-side regions during high solar activity, while electron temperature measurements are more reliable during night side at middle\u0000and low latitudes during low solar activity. The main anomalies affecting the Langmuir probe measurements are described, as well as possible\u0000improvements in the derived plasma parameters to be implemented in future baselines.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48460163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Miyamoto, Shogo Nagahara, K. Morishima, T. Nakano, M. Koyama, Yusuke Suzuki
Abstract. One of the key challenges for muographic studies is to reveal the detailed 3D density structure of a volcano by increasing the number of observation directions. 3D density imaging by multi-directional muography requires that the individual differences in the performance of the installed muon detectors are small and that the results from each detector can be derived without any bias in the data analysis. Here we describe a pilot muographic study of the Izu–Omuroyama scoria cone in Shizuoka Prefecture, Japan, from 11 directions, using a new nuclear emulsion detector design optimized for quick installation in the field. We describe the details of the data analysis and present a validation of the results. The Izu–Omuroyama scoria cone is an ideal target for the first multi-directional muographic study, given its expected internal density structure and the topography around the cone. We optimized the design of the nuclear emulsion detector for rapid installation at multiple observation sites in the field, and installed these at 11 sites around the volcano. The images in the developed emulsion films were digitized into segmented tracks with a high-speed automated readout system. The muon tracks in each emulsion detector were then reconstructed. After the track selection, including straightness filtering, the detection efficiency of the muons was estimated. Finally, the density distributions in 2D angular space were derived for each observation site by using a muon flux and attenuation models. The observed muon flux was compared with the expected value in the free sky, and is 88 % ± 4 % in the forward direction and 92 % ± 2 % in the backward direction. The density values were validated by comparison with the values obtained from gravity measurements, and are broadly consistent, except for one site. The excess density at this one site may indicate that the density inside the cone is non-axisymmetric, which is consistent with a previous geological study.
{"title":"A muographic study of a scoria cone from 11 directions using nuclear emulsion cloud chambers","authors":"S. Miyamoto, Shogo Nagahara, K. Morishima, T. Nakano, M. Koyama, Yusuke Suzuki","doi":"10.5194/gi-11-127-2022","DOIUrl":"https://doi.org/10.5194/gi-11-127-2022","url":null,"abstract":"Abstract. One of the key challenges for muographic studies is to reveal the detailed\u00003D density structure of a volcano by increasing the number of observation\u0000directions. 3D density imaging by multi-directional muography requires that\u0000the individual differences in the performance of the installed muon\u0000detectors are small and that the results from each detector can be derived\u0000without any bias in the data analysis. Here we describe a pilot muographic\u0000study of the Izu–Omuroyama scoria cone in Shizuoka Prefecture, Japan, from\u000011 directions, using a new nuclear emulsion detector design optimized for\u0000quick installation in the field. We describe the details of the data\u0000analysis and present a validation of the results. The Izu–Omuroyama scoria cone is an ideal target for the first\u0000multi-directional muographic study, given its expected internal density\u0000structure and the topography around the cone. We optimized the design of the\u0000nuclear emulsion detector for rapid installation at multiple observation\u0000sites in the field, and installed these at 11 sites around the volcano. The\u0000images in the developed emulsion films were digitized into segmented tracks\u0000with a high-speed automated readout system. The muon tracks in each emulsion\u0000detector were then reconstructed. After the track selection, including\u0000straightness filtering, the detection efficiency of the muons was estimated.\u0000Finally, the density distributions in 2D angular space were derived for each\u0000observation site by using a muon flux and attenuation models. The observed muon flux was compared with the expected value in the free sky,\u0000and is 88 % ± 4 % in the forward direction and 92 % ± 2 % in the backward direction. The density values were validated by\u0000comparison with the values obtained from gravity measurements, and are\u0000broadly consistent, except for one site. The excess density at this one site\u0000may indicate that the density inside the cone is non-axisymmetric, which is\u0000consistent with a previous geological study.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47896019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Francke, M. Heistermann, M. Köhli, Christian Budach, M. Schrön, S. Oswald
Abstract. Cosmic-ray neutron sensing (CRNS) is a non-invasive tool for measuring hydrogen pools such as soil moisture, snow or vegetation. The intrinsic integration over a radial hectare-scale footprint is a clear advantage for averaging out small-scale heterogeneity, but on the other hand the data may become hard to interpret in complex terrain with patchy land use. This study presents a directional shielding approach to prevent neutrons from certain angles from being counted while counting neutrons entering the detector from other angles and explores its potential to gain a sharper horizontal view on the surrounding soil moisture distribution. Using the Monte Carlo code URANOS (Ultra Rapid Neutron-Only Simulation), we modelled the effect of additional polyethylene shields on the horizontal field of view and assessed its impact on the epithermal count rate, propagated uncertainties and aggregation time. The results demonstrate that directional CRNS measurements are strongly dominated by isotropic neutron transport, which dilutes the signal of the targeted direction especially from the far field. For typical count rates of customary CRNS stations, directional shielding of half-spaces could not lead to acceptable precision at a daily time resolution. However, the mere statistical distinction of two rates should be feasible.
{"title":"Assessing the feasibility of a directional cosmic-ray neutron sensing sensor for estimating soil moisture","authors":"T. Francke, M. Heistermann, M. Köhli, Christian Budach, M. Schrön, S. Oswald","doi":"10.5194/gi-11-75-2022","DOIUrl":"https://doi.org/10.5194/gi-11-75-2022","url":null,"abstract":"Abstract. Cosmic-ray neutron sensing (CRNS) is a non-invasive tool for measuring hydrogen pools such as soil moisture, snow or vegetation. The intrinsic integration over a radial hectare-scale footprint is a clear advantage for averaging out small-scale heterogeneity, but on the other hand the data may become hard to interpret in complex terrain with patchy land use. This study presents a directional shielding approach to prevent neutrons from certain angles from being counted while counting neutrons entering the detector from other angles and explores its potential to gain a sharper horizontal view on the surrounding soil moisture distribution. Using the Monte Carlo code URANOS (Ultra Rapid Neutron-Only Simulation), we modelled the effect of additional polyethylene shields on the horizontal field of view and assessed its impact on the epithermal count rate, propagated uncertainties and aggregation time. The results demonstrate that directional CRNS measurements are strongly dominated by isotropic neutron transport, which dilutes the signal of the targeted direction especially from the far field. For typical count rates of customary CRNS stations, directional shielding of half-spaces could not lead to acceptable precision at a daily time resolution. However, the mere statistical distinction of two rates should be feasible.\u0000","PeriodicalId":48742,"journal":{"name":"Geoscientific Instrumentation Methods and Data Systems","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45560571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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