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Background: Low back pain is a significant contributor to global disability, impacting individuals across different age groups. Research suggests that around 80% of people will encounter low back pain at some stage in their lives. This condition is more prevalent among middle-aged and elderly individuals, with a higher occurrence among females. The socioeconomic consequences of low back pain are substantial, including increased healthcare expenses, absenteeism from work, and a diminished quality of life. Objective: To compare the effectiveness of short-wave diathermy with exercise, transcutaneous electrical nerve stimulation with exercise, and exercise alone among patients with chronic low back pain. Patients and Methods: 75 patients who were diagnosed with chronic low back pain, ages 20-50, participated. They were divided into three groups: group A received shortwave with exercise, group B received TENS with exercise, and group C received just exercise. Treatment was given for 12 sessions over a period of 4 weeks. All patients were evaluated before and after treatment using a visual analog scale and the Oswestry Low Back Pain Disability Questionnaire. Results: The results showed that all three interventions were effective in reducing pain and improving physical activities, with varying degrees of success. But also, the result showed that the mean difference for the short wave with exercise is much higher than both the TENS with exercise and the exercise alone types of interventions in each of the different categories, respectively. Conclusion: This study has shown that shortwave exercise is more effective in the treatment of chronic low back pain than TENS with exercise and exercise alone. [ABSTRACT FROM AUTHOR]

Background: Low back pain is a significant contributor to global disability, impacting individuals across different age groups. Research suggests that around 80% of people will encounter low back pain at some stage in their lives. This condition is more prevalent among middle-aged and elderly individuals, with a higher occurrence among females. The socioeconomic consequences of low back pain are substantial, including increased healthcare expenses, absenteeism from work, and a diminished quality of life. Objective: To compare the effectiveness of short-wave diathermy with exercise, transcutaneous electrical nerve stimulation with exercise, and exercise alone among patients with chronic low back pain. Patients and Methods: 75 patients who were diagnosed with chronic low back pain, ages 20–50, participated. They were divided into three groups: group A received shortwave with exercise, group B received TENS with exercise, and group C received just exercise. Treatment was given for 12 sessions over a period of 4 weeks. All patients were evaluated before and after treatment using a visual analog scale and the Oswestry Low Back Pain Disability Questionnaire. Results: The results showed that all three interventions were effective in reducing pain and improving physical activities, with varying degrees of success. But also, the result showed that the mean difference for the short wave with exercise is much higher than both the TENS with exercise and the exercise alone types of interventions in each of the different categories, respectively. Conclusion: This study has shown that shortwave exercise is more effective in the treatment of chronic low back pain than TENS with exercise and exercise alone.

In the field of electronic communication warfare, accurately predicting the range and intensity of shortwave interference signals presents a significant challenge due to the complex interplay between the ionospheric parameters and the electromagnetic environment. To address this challenge, we designed a novel tool to assess the interference impact area of shortwave interference signals in a dynamically changing ionospheric environment. Considering sophisticated ionospheric radio wave propagation models and innovative spatial grid methods, this tool finishes the comprehensive spatial distribution of the interference impact area and delivers grid-based insights into the interference intensity. Furthermore, the test verification of the tool demonstrated a mean error of 8.42 dB between the measured and simulated results, underscoring the efficacy and reliability of this tool. This pioneering work is poised to make substantial contributions to the field of communication electronic warfare and holds significant promise for guiding the development of interference countermeasures. [ABSTRACT FROM AUTHOR]

Studies have shown the influence of magnetic fields on several biological systems. Some of these fields, such as shortwave (SW) magnetic fields, have been used for therapeutic purposes. However, the possible adverse effects caused by this treatment still need to be better understood. The present study aimed to ascertain whether a single daily exposure (15 min.), for 15, 30 and 60 days, to SW magnetic field (27.12 MHz) can impede spermatogenesis. Exposure to SW magnetic fields did not change the weight of body, testis, epididymis, prostate, seminal vesicle or the gonadosomatic index. The plasma testosterone levels and testicular component volumes (seminiferous tubules, lumen, lamina propria, connective tissue, blood vessels, intertubular tissue) also remained unchanged. Histopathological analysis and spermatogenesis markers showed no changes after exposure to SW magnetic fields. However, some analyses showed changes in the lamina propria, daily sperm production, individual volume and population of Leydig cells. In conclusion, exposure to SW magnetic field for up to 60 days seems to be safe for spermatogenesis, but this exposure caused minor testicular changes that need to be better understood in the long term. This is of particular interest to health professionals who handle such SW devices for long periods of time. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Data Acquisition & Processing / Shu Ju Cai Ji Yu Chu Li is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the field of electronic communication warfare, accurately predicting the range and intensity of shortwave interference signals presents a significant challenge due to the complex interplay between the ionospheric parameters and the electromagnetic environment. To address this challenge, we designed a novel tool to assess the interference impact area of shortwave interference signals in a dynamically changing ionospheric environment. Considering sophisticated ionospheric radio wave propagation models and innovative spatial grid methods, this tool finishes the comprehensive spatial distribution of the interference impact area and delivers grid-based insights into the interference intensity. Furthermore, the test verification of the tool demonstrated a mean error of 8.42 dB between the measured and simulated results, underscoring the efficacy and reliability of this tool. This pioneering work is poised to make substantial contributions to the field of communication electronic warfare and holds significant promise for guiding the development of interference countermeasures.

Coordinated positioning based on direction of arrival (DOA)–time difference of arrival (TDOA) is a research area of great interest in beyond-visual-range target positioning with shortwave. The DOA estimation accuracy greatly affects the accuracy of coordinated positioning. With existing positioning methods, the elevation angle's estimation accuracy in multipath propagation decreases sharply. Accordingly, the positioning accuracy also decreases. In this paper, the elevation angle is modeled as a random variable, with its probability distribution reflecting the characteristics of multipath propagation. A new coordinated positioning method based on DOA–TDOA and Bayesian estimation with shortwave anti-multipath is proposed. First, a convolutional neural network is used to learn the three-dimensional spatial spectrogram to make an intelligent decision on the number of single and multiple paths, and to obtain a probability distribution of the elevation angle under multiple paths. Second, the elevation angle's estimated value is modified using the elevation angle's probability distribution. The modified elevation angle's estimated value is substituted into a DOA pseudo-linear observation equation, and the target position's estimated value is obtained using the matrix QR decomposition iteration algorithm. Finally, a TDOA pseudo-linear observation equation is established using the target estimate obtained in the DOA stage, and the coordinated positioning result is obtained using the matrix QR decomposition iteration algorithm again. Simulation results demonstrated that the proposed method had a stronger anti-multipath capability than traditional methods, and it improved the coordinated positioning accuracy of the DOA and TDOA. Measured data were used to validate the proposed method. [ABSTRACT FROM AUTHOR]

The shortwave direct radiative effect of dust, the difference between net shortwave radiative flux in a cloud free and cloud and aerosol free atmosphere, is typically estimated using forward calculations made with a radiative transfer model. However, estimates of the direct radiative effect made via this initial method can be highly uncertain due to difficultly in accurately describing the relevant optical and physical properties of dust used in these calculations. An alternative approach to estimate this effect is to determine the forcing efficiency, or the direct radiative effect normalized by aerosol optical depth. While this approach avoids the uncertainties associated with the initial method for calculating the direct effect, random errors and biases associated with this approach have not been thoroughly examined in literature. Here we explore biases in this observation‐based approach that are related to atmospheric water vapor. We use observations to show that over the Sahara Desert dust optical depth and column‐integrated atmospheric water vapor are positively correlated. We use three idealized radiative models of varying complexity to demonstrate that a positive correlation between dust and water vapor produces a positive bias in the dust forcing efficiency estimated via the observation‐based method. We describe a simple modification to the observation‐based method that correctly accounts for the correlation between dust and water vapor when estimating the forcing efficiency and use this method to estimate the instantaneous forcing efficiency of dust over the Sahara Desert using satellite data, obtaining −12.3 ± 6.68 to 20.9 ± 11.9 W m−2 per unit optical depth. Plain Language Summary: The presence of suspended dust in the Earth's atmosphere affects the planetary energy budget via the direct radiative effect, and researchers typically use radiative transfer models to quantify the magnitude of this effect. However calculations of the direct radiative effect made in this manner are highly uncertain due to a lack of precise knowledge of a number of relevant dust properties. An observation‐based approach that circumvents these challenges exists, yet uncertainties associated with this method have not been extensively investigated. Here we identify one physical mechanism that produces a bias when estimating the dust direct effect via the observational approach, which is the observed correlation between atmospheric water vapor and dust. We describe a simple solution to account for this effect in direct effect calculations and then use this corrected method along with data from satellites to estimate the dust direct effect over North Africa, finding a smaller value than what had been reported by earlier studies. Key Points: Biases in dust shortwave forcing efficiency estimated via observational methods arise due to solar aborption of water vaporAn observational method is described that accounts for potential biases in the dust shortwave forcing efficiencyWhen applied to data over North Africa we estimate the dust shortwave forcing efficiency to lie within in –12.3 to –20.9 W m−2 per unit optical depth [ABSTRACT FROM AUTHOR]

Copyright of Journal of Signal Processing is the property of Journal of Signal Processing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We introduce and demonstrate new measurement and modeling techniques to fully resolve the spatial variation in shortwave and longwave radiant heat transfer in the outdoor environment. We demonstrate for the first time a way to directly resolve the shortwave radiant heat transfer from terrestrial reflected and diffuse sky components along with the standard direct solar radiation using an adapted thermopile array and ray-tracing modeling techniques validated by 6-direction net radiometer. Radiant heat transfer is a major component of heat experienced in cities. It has significant spatial variability that is most easily noticed as one moves between shade and direct solar exposure. But even on a cloudy and warm day the invisible longwave infrared thermal radiation from warm surfaces makes up a larger fraction of heat experienced than that caused by convection with surrounding air. Under warm or hot climate conditions in cities, radiant heat transfer generally accounts for the majority of heat transfer to people. Both the shortwave (visible/solar) and the longwave (infrared/thermal) have significant spatial variation. We demonstrate sensor methods and data analysis techniques to resolve how these radiant fluxes can change the heat experienced by >1 kWm−2 across small distances. The intense solar shortwave radiation is easily recognized outdoors, but longwave is often considered negligible. Longwave radiation from heat stored in urban surfaces is more insidious as it can cause changes invisible to the eye. We show how it changes heat experienced by >200 Wm−2. These variations are very common and also occur at the scale of a few meters.

Studies have shown the influence of magnetic fields on several biological systems. Some of these fields, such as shortwave (SW) magnetic fields, have been used for therapeutic purposes. However, the possible adverse effects caused by this treatment still need to be better understood. The present study aimed to ascertain whether a single daily exposure (15 min.), for 15, 30 and 60 days, to SW magnetic field (27.12 MHz) can impede spermatogenesis. Exposure to SW magnetic fields did not change the weight of body, testis, epididymis, prostate, seminal vesicle or the gonadosomatic index. The plasma testosterone levels and testicular component volumes (seminiferous tubules, lumen, lamina propria, connective tissue, blood vessels, intertubular tissue) also remained unchanged. Histopathological analysis and spermatogenesis markers showed no changes after exposure to SW magnetic fields. However, some analyses showed changes in the lamina propria, daily sperm production, individual volume and population of Leydig cells. In conclusion, exposure to SW magnetic field for up to 60 days seems to be safe for spermatogenesis, but this exposure caused minor testicular changes that need to be better understood in the long term. This is of particular interest to health professionals who handle such SW devices for long periods of time. [ABSTRACT FROM AUTHOR]

Copyright of Remote Sensing for Natural Resources is the property of Remote Sensing for Natural Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coordinated positioning based on direction of arrival (DOA)–time difference of arrival (TDOA) is a research area of great interest in beyond-visual-range target positioning with shortwave. The DOA estimation accuracy greatly affects the accuracy of coordinated positioning. With existing positioning methods, the elevation angle’s estimation accuracy in multipath propagation decreases sharply. Accordingly, the positioning accuracy also decreases. In this paper, the elevation angle is modeled as a random variable, with its probability distribution reflecting the characteristics of multipath propagation. A new coordinated positioning method based on DOA–TDOA and Bayesian estimation with shortwave anti-multipath is proposed. First, a convolutional neural network is used to learn the three-dimensional spatial spectrogram to make an intelligent decision on the number of single and multiple paths, and to obtain a probability distribution of the elevation angle under multiple paths. Second, the elevation angle’s estimated value is modified using the elevation angle’s probability distribution. The modified elevation angle’s estimated value is substituted into a DOA pseudo-linear observation equation, and the target position’s estimated value is obtained using the matrix QR decomposition iteration algorithm. Finally, a TDOA pseudo-linear observation equation is established using the target estimate obtained in the DOA stage, and the coordinated positioning result is obtained using the matrix QR decomposition iteration algorithm again. Simulation results demonstrated that the proposed method had a stronger anti-multipath capability than traditional methods, and it improved the coordinated positioning accuracy of the DOA and TDOA. Measured data were used to validate the proposed method.

Studies have shown the influence of magnetic fields on several biological systems. Some of these fields, such as shortwave (SW) magnetic fields, have been used for therapeutic purposes. However, the possible adverse effects caused by this treatment still need to be better understood. The present study aimed to ascertain whether a single daily exposure (15 min.), for 15, 30 and 60 days, to SW magnetic field (27.12 MHz) can impede spermatogenesis. Exposure to SW magnetic fields did not change the weight of body, testis, epididymis, prostate, seminal vesicle or the gonadosomatic index. The plasma testosterone levels and testicular component volumes (seminiferous tubules, lumen, lamina propria, connective tissue, blood vessels, intertubular tissue) also remained unchanged. Histopathological analysis and spermatogenesis markers showed no changes after exposure to SW magnetic fields. However, some analyses showed changes in the lamina propria, daily sperm production, individual volume and population of Leydig cells. In conclusion, exposure to SW magnetic field for up to 60 days seems to be safe for spermatogenesis, but this exposure caused minor testicular changes that need to be better understood in the long term. This is of particular interest to health professionals who handle such SW devices for long periods of time.

Design of high-power shortwave broadcast transmitters is one among the rare areas in the field of radiofrequency (RF) electronics, where the electron tube, as the main element for amplification of RF signal, is still in active use. The first successful attempts to replace the electron tube with solid-state components, primarily in the output stage amplifier modules for the Digital Radio Mondiale (DRM) shortwave broadcast transmitters have been published only recently. With the latest technology advancements in RF power transistors, it is now possible for commercially available RF power MOSFET transistors to be used for switching purposes at shortwave frequencies. Here, an architecture of a 10 kW shortwave broadcast transmitter with solid-state power amplifier modules in the RF output stage is proposed. Different implementations of the RF output stage that include power adding network from each amplifier module and the output matching network are analysed, both analytically and numerically. After choosing the optimal architecture, a prototype of a commercial shortwave DRM broadcast transmitter was designed and constructed, measured, tuned and tested at RIZ Transmitter factory Zagreb.

To detect the effects of shortwave radiation on dose-dependent cardiac structure and function in rats after radiation and to elucidate the mechanism of shortwave radiation induced cardiac injury to identify sensitive indicators and prophylactic treatment. One hundred Wistar rats were either exposed to 27 MHz continuous shortwave at a power density of 5, 10, and 30 mW/cm2 for 6 min or undergone sham exposure for the control (the rats had to be placed in the exposure system with the same schedules as the exposed animals, but with an inactive antenna). The Ca2+, glutamic oxaloacetic transaminase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) content in the peripheral serum of the rats were detected by an automatic blood biochemical analyser. The electrocardiogram (ECG) of standard lead II was recorded by a multi-channel physiological recording and analysis system. The cardiac structure of rats was observed by light and electron microscopy. The results showed that the 5, 10, and 30 mW/cm2 shortwave radiation caused a significant increased in the levels of Ca2+, AST, CK, and LDH in the peripheral serum of rats. The cardiac structure was damaged by radiation and showed a disordered arrangement of myocardial fibres, the cavitation and swelling of myocardial mitochondria. These injuries were most significant 7 d after radiation and were not restored until 28 d after radiation. Shortwave radiation of 5, 10, and 30 mW/cm2 can damage rat cardiac function, including damage to the tissue structure and ultrastructure, especially at the level of the myocardial fibres and mitochondria. Shortwave radiation at 5, 10, and 30 mW/cm2 induced damage to rat heart function and structure with a dose-effect relationship, i.e., the greater the radiation dose was, the more significant the damage was. [ABSTRACT FROM AUTHOR]

Decadal aerosol characteristics and related radiative effects (ARE) and efficiencies (AREE) at ultraviolet (UV), visible (VIS), near‐infrared (NIR), and shortwave wavelengths were investigated in Wuhan during winter haze periods based on observations from 2007 to 2016. Aerosols changed significantly under haze conditions; the average aerosol optical depth increased from 0.46 to 0.93, and the Ångström exponent increased from 1.12 to 1.23. Fine‐mode particles became dominant, and their peak radius also increased due to hygroscopic growth. The mean value of the UV single‐scattering albedo increased from 0.846 to 0.873, revealing the emergence of numerous fine‐mode, nonabsorbing aerosols. Backward trajectories suggested that local aerosols were partially affected by transported dust from Northwest China, especially in 2015. The interannual variation of the mean AREE at the top of atmosphere showed a gradually increasing tendency, revealing the enhanced potential cooling capacity of aerosols to the Earth‐atmosphere system over Wuhan. The increase in the AREE fraction at UV and VIS wavelengths, and its decrease at NIR wavelengths, indicated that this phenomenon was due to the increased proportion of fine‐mode scattering components in aerosols. The variation in AREE at top of atmosphere depended mainly on the single‐scattering albedo, while the same variation at the surface depended more on particle sizes. A detailed investigation of aerosols during haze periods can help us to further understand localized climate variations and haze‐inducing mechanisms. Key Points: Aerosol optical and microphysical characteristics and related radiative effects at various wavelengths were investigated during hazeAerosols changed significantly under haze conditions; average aerosol optical depths increased, and fine‐mode particles became dominantInterannual variation of aerosol radiative effect efficiencies at top of the atmosphere showed an enhancing tendency [ABSTRACT FROM AUTHOR]

Abstract With the increasing knowledge of shortwave radiation, it is widely used in wireless communications, radar observations, industrial manufacturing, and medical treatments. Despite of the benefits from shortwave, these wide applications expose humans to the risk of shortwave electromagnetic radiation, which is alleged to cause potential damage to biological systems. This review focused on the exposure to shortwave electromagnetic radiation, considering in vitro, in vivo and epidemiological results that have provided insight into the biological effects and mechanisms of shortwave. Additionally, some protective measures and suggestions are discussed here in the hope of obtaining more benefits from shortwave with fewer health risks.

This research work is focused on the construction of an accurate longwave/shortwave radiation model on a tunnel greenhouse pseudo-bond graph model, widely used in Tunisia. This model includes sun position, useful incoming solar radiation model, sky longwave radiation model, inside longwave and shortwave radiation model. The key idea is to use bond graphs allowing a lumped modelling approach which is suitable for control applications. Furthermore, an evaluation of some longwave radiative model components was made, noting that these components are particularly sensitive regarding to the thermal behaviour of the model. Experimental tunnel greenhouse data are used as validation elements for the present model with globally good results. A comparative study was also performed between the present model and a previous bond graph model containing a simplistic radiative model. Practical simulation results show a clear improvement compared with the previous model. [ABSTRACT FROM AUTHOR]

Aerosol optical properties and corresponding radiative effect (ARE) in ultraviolet (UV), visible (VIS), near-infrared (NIR), and shortwave (SW) during haze periods between winter and summer of Wuhan were compared. With the development of haze, the average aerosol optical depth (AOD) increased from 0.34 to 0.79 in winter and from 0.64 to 1.36 in summer. The aerosol volume size distribution (ASD) showed that obvious increases in fine mode particles in both winter and summer with haze occurring. The single scattering albedo (SSA) increased significantly in both seasons as a result of the emergence of numerous non-absorbent aerosols when haze occurred. The ARE at UV, VIS, NIR, and SW changed in winter (summer) from -8.29 W/m2 to -10.88 W/m2 (- 8.32 W/m2 to -11.06 W/m2), from -43.26 W/m2 to -66.04 W/m2 (56.33 W/m2 to -76.94 W/m2), from -21.90 W/m2 to -44.57 W/m2 (- 31.36 W/m2 to -48.67 W/m2), and from -73.46 W/m2 to -119.49 W/m2 (-8.32 W/m2 to -11.06 W/m2) respectively, when air conditions changed from clear to hazy. The variations in ARE fraction of UV, VIS, and NIR in SW depended much more on particle size rather than SSA. The ARE fraction of UV and VIS decreased while it of NIR increased in SW, when haze developed. Back trajectory analysis with active fire areas from Moderate Resolution Imaging Spectroradiometer (MODIS) indicated that the BC originated from the North in summer, while active fires in winter were rare. [ABSTRACT FROM AUTHOR]

As infrastructure decays rapidly due to structural and material aging and failures, the development of new improved, and efficient nondestructive evaluation (NDE) techniques is vital for system health monitoring and preventive maintenance. Composite material, such as carbon fiber reinforced polymer (CFRP) plays a significant role in energy and transportation infrastructure due to the advantages of corrosion resistance, durability, and lightweight, which contributes to minimal maintenance and long service life. However, due to their unique anisotropic dielectric and mechanical characteristics, detecting composite material defects by NDE techniques is still challenging. This paper presents a novel, low-cost miniaturized multi-modality imaging system combining low-frequency capacitive shortwave and high-frequency microwave NDE technologies to detect various types of defects in CFRP materials. Based on the governing electromagnetic theory behind multi-modality electromagnetic NDE methods, the merit of combining low-frequency shortwave and near-field microwave imaging for dielectric characterization of composite materials is thoroughly investigated and demonstrated. Then, a miniaturized imaging system is developed to operate at ultra-wide bands: 10 kHz to 200 MHz for the capacitive shortwave probes and 1 GHz to 9 GHz for the microwave probes. Customized multi-material joining samples of CFRP and steel with different defect types, locations, depths, and sizes are tested by the developed imaging system, and the experimental results of the miniaturized system are compared with the existing table-top systems, which demonstrates comparatively accurate results for the developed multi-modality imaging system. The compact and practical nature of the presented imaging system makes it an optimal tool that can be utilized in field conditions with constrained operational spaces and NDE uncertainties. [ABSTRACT FROM AUTHOR]

The current lack of a long, 30+ year, global climate data record of reflected shortwave top-of-atmosphere (TOA) radiation could be tackled by relying on existing narrowband records from the Advanced Very High Resolution Radiometer (AVHRR) instruments, and transform these measurements into broadband quantities like provided by the Clouds and the Earth’s Radiant Energy System (CERES). This paper presents the methodology of an AVHRR-to-CERES narrowband-to-broadband conversion for shortwave TOA reflectance, including the ready-to-use results in the form of scene-type dependent regression coefficients, allowing a calculation of CERES-like shortwave broadband reflectance from AVHRR channels 1 and 2. The coefficients are obtained using empirical relations in a large data set of collocated, coangular and simultaneous AVHRR-CERES observations, requiring specific orbital conditions for the AVHRR- and CERES-carrying satellites, from which our data analysis uses all available data for an unprecedented observation matching between both instruments. The multivariate linear regressions were found to be robust and well-fitting, as demonstrated by the regression statistics on the calibration subset (80% of data): adjusted R 2 higher than 0.9 and relative RMS residual mostly below 3%, which is a significant improvement compared to previous regressions. Regression models are validated by applying them on a validation subset (20% of data), indicating a good performance overall, roughly similar to the calibration subset, and a negligible mean bias. A second validation approach uses an expanded data set with global coverage, allowing regional analyses. In the error analysis, instantaneous accuracy is quantified at regional scale between 1.8 Wm − 2 and 2.3 Wm − 2 (resp. clear-sky and overcast conditions) at 1 standard deviation (RMS bias). On daily and monthly time scales, these errors correspond to 0.7 and 0.9 Wm − 2 , which is compliant with the GCOS requirement of 1 Wm − 2 .