A New Soil Moisture Agricultural Drought Index (SMADI) Integrating MODIS and SMOS Products: A Case of Study over the Iberian Peninsula

25 pages, 9 figures, 4 tablesA new index for agricultural drought monitoring is presented based on the integration of different soil/vegetation remote sensing observations. The synergistic fusion of the surface soil moisture (SSM) from the Soil Moisture and Ocean Salinity (SMOS) mission, with the Moderate Resolution Imaging Spectroradiometer (MODIS) derived land surface temperature (LST), and water/vegetation indices for agricultural drought monitoring was tested. The rationale of the approach is based on the inverse relationship between LST, vegetation condition and soil moisture content. Thus, the proposed Soil Moisture Agricultural Drought Index (SMADI) combines the soil and temperature conditions while including the lagged response of vegetation. SMADI was retrieved every eight days at 500 m spatial resolution for the whole Iberian Peninsula (IP) from 2010 to 2014, and a time lag of eight days was used to account for the plant response to the varying soil/climatic conditions. The results of SMADI compared well with other agricultural indices in a semiarid area in the Duero basin, in Spain, and also with a climatic index in areas of the Iberian Peninsula under contrasted climatic conditions. Based on a standard classification of drought severity, the proposed index allowed for a coherent description of the drought conditions of the IP during the study periodThis study was supported by the Spanish Ministry of Economy and Competitiveness, MINECO (Projects AYA2012-39356-C05 and ESP2015-67549-C3-3) and the European Regional Development Fund, FEDER. Partial funding was also received from the BBVA FoundationPeer Reviewe

Segmentation strategy for the efficient analysis and design of substrate integrated waveguide directly coupled cavity filters

This paper is a postprint of a paper submitted to and accepted for publication in IET Microwaves Antennas and Propagation and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital LibraryIn this study, a new segmentation strategy is presented for the full-wave analysis of directly coupled cavity filters in substrate integrated waveguide (SIW) technology. The whole SIW filter is enclosed inside an external fictitious rectangular waveguide, which does not affect the propagation inside the SIW assuming that the SIW is well designed and there is no significant power leakage. The external rectangular waveguide allows to easily segment the structure into building blocks that are composed of circular metallic vias inside a rectangular waveguide. The generalised scattering matrix of these building blocks is obtained with highly efficient techniques specifically suited for the analysis of H-plane rectangular waveguide devices. Some building blocks are repeated along the structure, and their scattering matrix has to be computed only once. The scattering matrices of all the building blocks are cascaded and the scattering matrix of the whole filter is obtained. A SIW filter of eight coupled cavities with a bandpass response centred at 11 GHz is analysed. Results from this analysis show that the computational time has been significantly reduced when compared with other specific SIW analysis methods or with commercial general purpose software, while maintaining a good accuracy.This work was funded by the Ministerio de Economia y Competitividad of the Spanish Government under the project number TEC2013-47037-C5-1-R.Martínez-Zamora, JÁ.; Belenguer, Á.; Esteban González, H.; Boria Esbert, VE. (2016). Segmentation strategy for the efficient analysis and design of substrate integrated waveguide directly coupled cavity filters. IET Microwaves Antennas and Propagation. 10(3):283-287. https://doi.org/10.1049/iet-map.2015.0284S28328710

Fast Frequency Sweep Technique Based on Segmentation for the Acceleration of the Electromagnetic Analysis of Microwave Devices

[EN] The characterization of communication devices in a certain frequency band can be accelerated if a fast frequency sweep technique is used instead of a discrete frequency sweep. Existing fast frequency sweep techniques are either complex or specific for a certain electromagnetic solver. In this work, a new fast frequency sweep method is proposed that consists in segmenting the device under analysis into simple building blocks. Each building block is characterized with a generalized (multimode) circuital matrix whose elements present a simple and flat frequency response that is interpolated using natural cubic splines with very few points. In this way, the response of each block along the whole frequency band is obtained efficiently and accurately with as many frequency points as desired. Then, the circuital matrices of all the blocks are cascaded and the circuital matrix of the whole device in obtained. The new fast frequency sweep was successfully applied to the analysis of different types of devices (all metallic rectangular waveguide filter, dielectric loaded rectangular waveguide filter, and substrate integrated waveguide filter). The computational times were reduced to 15% or 19%, depending on the device, when compared with a discrete frequency sweep using the same electromagnetic solver.This research was funded by Ministerio de Economia, Industria y Competitividad, Spanish Government, under Research Projects TEC2016-75934-C4-3-R and TEC2016-75934-C4-1-R.Martínez-Zamora, JÁ.; Belenguer Martínez, A.; Esteban González, H. (2019). Fast Frequency Sweep Technique Based on Segmentation for the Acceleration of the Electromagnetic Analysis of Microwave Devices. Applied Sciences. 9(6):1-16. https://doi.org/10.3390/app9061118S11696Erdemli, Y. E., Reddy, C. J., & Volakis, J. L. (1999). Awe Technique in Frequency Domain Electromagnetics. Journal of Electromagnetic Waves and Applications, 13(3), 359-378. doi:10.1163/156939399x00961Reddy, C. J., Deshpande, M. D., Cockrell, C. R., & Beck, F. B. (1998). Fast RCS computation over a frequency band using method of moments in conjunction with asymptotic waveform evaluation technique. IEEE Transactions on Antennas and Propagation, 46(8), 1229-1233. doi:10.1109/8.718579Polstyanko, S. V., Dyezij-Edlinger, R., & Jin-Fa Lee. (1997). Fast frequency sweep technique for the efficient analysis of dielectric waveguides. IEEE Transactions on Microwave Theory and Techniques, 45(7), 1118-1126. doi:10.1109/22.598450Chiprout, E., & Nakhla, M. S. (1995). Analysis of interconnect networks using complex frequency hopping (CFH). IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 14(2), 186-200. doi:10.1109/43.370425Gustavsen, B., & Semlyen, A. (1999). Rational approximation of frequency domain responses by vector fitting. IEEE Transactions on Power Delivery, 14(3), 1052-1061. doi:10.1109/61.772353Bandler, J. W., Biernacki, R. M., Shao Hua Chen, & Ya Fei Huang. (1997). Design optimization of interdigital filters using aggressive space mapping and decomposition. IEEE Transactions on Microwave Theory and Techniques, 45(5), 761-769. doi:10.1109/22.575598Ros, J. V. M., Pacheco, P. S., Gonzalez, H. E., Esbert, V. E. B., Martin, C. B., Calduch, M. T., … Martinez, B. G. (2005). Fast automated design of waveguide filters using aggressive space mapping with a new segmentation strategy and a hybrid optimization algorithm. IEEE Transactions on Microwave Theory and Techniques, 53(4), 1130-1142. doi:10.1109/tmtt.2005.845685Alos, J. T., & Guglielmi, M. (1997). Simple and effective EM-based optimization procedure for microwave filters. IEEE Transactions on Microwave Theory and Techniques, 45(5), 856-858. doi:10.1109/22.575610Bachiller, C., Gonzalez, H. E., Boria Esbert, V. E., Belenguer Martinez, A., & Morro, J. V. (2007). Efficient Technique for the Cascade Connection of Multiple Two-Port Scattering Matrices. IEEE Transactions on Microwave Theory and Techniques, 55(9), 1880-1886. doi:10.1109/tmtt.2007.904076Interpolación de Splineshttps://www.uv.es/diaz/mn/node40.htmlBachiller, C., Esteban, H., Mata, H., Valdes, M. Á., Boria, V. E., Belenguer, Á., & Morro, J. V. (2010). Hybrid Mode Matching Method for the Efficient Analysis of Metal and Dielectric Rods in H Plane Rectangular Waveguide Devices. IEEE Transactions on Microwave Theory and Techniques. doi:10.1109/tmtt.2010.208395

Our ten years of work on transparet box business simulation

Traditional business games are of the so-called black-box type (BBBS=Black box business simulator); that is to say, the internal structure which generates the results of the simulation after decision-making is not known. As a result, the player normally operates by trial and error and bases his decisions on the symptoms of the problem (the observed behaviors of the system's variables) and not on the real causes of the problem (the system's structure). Since 1988 José A.D. Machuca has insisted that the business games based on System Dynamics models should be Transparent-box business simulators (TBBSs). That means that, during the game, the user has access to the structure of the underlying model and is able to relate it to the observed behaviors. The hypothesis is that such transparency would facilitate causal reflection and favor systemic learning of business problems. In 1990, the G.I.D.E.A.O. Research Group took action on this idea and centered one of its lines of research on this matter, with three main objectives: a) Creation of TBBSs, b) Introduction of TBBSs in undergraduate and graduate Management courses as well as in executive training, c) Experimentation in controlled environments in order to test the hypothesis mentioned in the above paragraph. Now, ten years after the birth of the idea, we would like to share in this paper the results obtained during that period

Assessment of SMADI and SWDI agricultural drought indices using remotely sensed root zone soil moisture

[EN]The increasing frequency of drought events has expanded the research interest in drought monitoring. In this regard, remote sensing is a useful tool to globally mapping the agricultural drought. While this type of drought is directly linked to the availability of root zone soil moisture (RZSM) for plants growth, current satellite soil moisture observations only characterize the water content of the surface soil layer (0–5 cm). In this study, two soil moisture-based agricultural drought indices were obtained at a weekly rate from June 2010 to December 2016, using RZSM estimations at 1 km from the Soil Moisture and Ocean Salinity (SMOS) satellite, instead of surface soil moisture (SSM). The RZSM was estimated by applying the Soil Water Index (SWI) model to the SMOS SSM. The Soil Moisture Agricultural Drought Index (SMADI) and the Soil Water Deficit Index (SWDI) were assessed over the Castilla y León region (Spain) at 1 km spatial resolution. They were compared with the Atmospheric Water Deficit (AWD) and the Crop Moisture Index (CMI), both computed at different weather stations distributed over the study area. The level of agreement was analyzed through statistical correlation. Results showed that the use of RZSM does not influence the characterization of drought, both for SMADI and SWDI

Assessment of Root Zone Soil Moisture Estimations from SMAP, SMOS and MODIS Observations

[EN]In this study, six satellite-based root zone soil moisture (RZSM) estimates from March 2015 to December 2016 were evaluated both temporally and spatially. The first two were the Soil Moisture Active Passive (SMAP) and the Soil Moisture and Ocean Salinity (SMOS) L4 RZSM products. The other four were obtained through the Soil Water Index (SWI) approach, which embedded surface soil moisture (SSM). The SMOS-Barcelona Expert Center (BEC) L4 SSM product and the apparent thermal inertia (ATI)-derived SSM from the Moderate Resolution Imaging Spectroradiometer (MODIS) data were used as SSM datasets. In the temporal analysis, the RZSM estimates were compared to in situ RZSM from 14 stations of the Soil Moisture Measurements Station Network of the University of Salamanca (REMEDHUS). Regarding the spatial assessment, the resulting RZSM maps of the Iberian Peninsula were compared between them. All RZSM values followed the temporal evolution of the ground-based measurements well, although SMOS and MODIS showed underestimation while SMAP displayed overestimation. The good results obtained from MODIS ATI are notable, notwithstanding they were not estimated through microwave radiometry. A very high agreement was found in terms of spatial patterns for the whole Iberian Peninsula except for the extreme north area, which is dominated by high mountains and dense forests

Feature Selection for Blood Glucose Level Prediction in Type 1 Diabetes Mellitus by Using the Sequential Input Selection Algorithm (SISAL)

Feature selection is a primary exercise to tackle any forecasting task. Machine learning algorithms used to predict any variable can improve their performance by lessening their computational effort with a proper dataset. Anticipating future glycemia in type 1 diabetes mellitus (DM1) patients provides a baseline in its management, and in this task, we need to carefully select data, especially now, when novel wearable devices offer more and more information. In this paper, a complete characterization of 25 diabetic people has been carried out, registering innovative variables like sleep, schedule, or heart rate in addition to other well-known ones like insulin, meal, and exercise. With this ground-breaking data compilation, we present a study of these features using the Sequential Input Selection Algorithm (SISAL), which is specially prepared for time series data. The results rank features according to their importance, regarding their relevance in blood glucose level prediction as well as indicating the most influential past values to be taken into account and distinguishing features with person-dependent behavior from others with a common performance in any patient. These ideas can be used as strategies to select data for predicting glycemia depending on the availability of computational power, required speed, or required accuracy. In conclusion, this paper tries to analyze if there exists symmetry among the different features that can affect blood glucose levels, that is, if their behavior is symmetric in terms of influence in glycemia.This work has been sponsored by the Spanish Ministry of Economy and Competitiveness through 387 the PERSEIDES (ref. TIN2017-86885-R) and CHIST-ERA (ref. PCIN-2016-010) projects; by MINECO grant BES-2015-071956 and by the European Commission through the H2020-ENTROPY-649849 EU Project. The authors would like to thank to the Endocrinology Department of the Morales Meseguer and Virgen de la Arrixaca hospitals of the city of Murcia (Spain)

Towards improved spatio-temporal resolution soil moisture retrievals from the synergy of SMOS and MSG SEVIRI spaceborne observations

The final publication is available at Springer via http://dx.doi.org/10.1016/j.rse.2016.02.048Earth Observation (EO) technology is today at a maturity level that allows deriving operational estimates of Surface Soil Moisture (SSM) from a variety of sensors; yet, such products are provided at present at a coarse spatial and/or temporal resolution, which restricts their use in local or regional scale studies and practical applications. Herein, a methodology to derive SSM estimates from space at previously unattained spatio-temporal resolutions is proposed. The method is based on a variant of thePeer ReviewedPostprint (author's final draft

Validation of SMOS L2 and L3 soil moisture products over the Duero Basin at different spatial scales

36th International Symposium on Remote Sensing of Environment, 11-15 May 2015, Berlin, Germany.-- 6 pages, 3 figures, 3 tablesAn increasing number of permanent soil moisture measurement networks are nowadays providing the means for validating new remotely sensed soil moisture estimates such as those provided by the ESA’s Soil Moisture and Ocean Salinity (SMOS) mission. Two types of in situ measurement networks can be found: small-scale (100–10000 km2), which provide multiple ground measurements within a single satellite footprint, and large-scale (>10000 km2), which contain a single point observation per satellite footprint. This work presents the results of a comprehensive spatial and temporal validation of a long-term (January, 2010 to June, 2014) dataset of SMOS-derived soil moisture estimates using two in situ networks within the Duero basin (Spain). The first one is the Soil Moisture Measurement Stations Network of the University of Salamanca (REMEDHUS), which has been extensively applied for validation of soil moisture remote sensing observations, including SMOS. REMEDHUS can be considered within the small-scale network group (1300 km2). The other network started from an existing meteorological network from the Castilla y León region, where soil moisture probes were incorporated in 2012. This network can be considered within the large-scale group (65000 km2). Results from comparison to in situ show that the new reprocessed L2 product (v5.51) improves the accuracy of former soil moisture retrievals, making them suitable for developing new L3 products. Validation based on comparisons between dense/sparse networks showed that temporal patterns on soil moisture are well reproduced, whereas spatial patterns are difficult to depict given the different spatial representativeness of ground and satellite observationsThis work was supported by the Spanish Ministry of Economy and Competitiveness (Project AYA2012-39356-C05). Ángela Gumuzzio acknowledges support from the FPI grant BES-2011-050439Peer Reviewe

Integration of a Very High Quality Factor Filter in Empty Substrate Integrated Waveguide at Q-band

© 2018 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] Recently, new methodologies for manufacturing empty waveguides completely integrated in a planar substrate have been proposed in order to improve the performance of substrate-integrated devices. One of these alternatives is the so-called empty substrate-integrated waveguide (ESIW). The height of high-frequency substrates, where ESIW devices are integrated, is very small. Then, the capacity of storing energy of ESIW resonators is drastically reduced, and as a result, their quality factor is not as high as it could be with a higher ESIW. In order to overcome this restriction, a novel integrated structure is proposed to embed very high-quality factor filters based on the ESIW with an increased height. As a result, we show, in this letter, for the first time, the successful integration of an increased-height ESIW filter in a printed circuit board of 0.305 mm height at Q-band, achieving a quality factor above 1000, which is a remarkable result for a completely substrate-integrated device operating in this frequency band. When compared with the same filter manufactured with an ESIW with the same height as the substrate, the novel filter shows a measured quality factor 85% higher.This work was supported by the Ministerio de Economia y Competitividad, Spanish Government, under Project TEC2016-75934-C4-3-R and Project TEC2016-75934-C4-1-R.Martínez-Zamora, JÁ.; De Dios, JJ.; Belenguer Martínez, Á.; Esteban González, H.; Boria Esbert, VE. (2018). Integration of a Very High Quality Factor Filter in Empty Substrate Integrated Waveguide at Q-band. IEEE Microwave and Wireless Components Letters. 28(6):503-505. https://doi.org/10.1109/LMWC.2018.2833214S50350528