2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)最新文献

{"title":"Radio Frequency Interference (RFI) Observed Over Water Surfaces at 18.6–18.8 GHz and the IEEE GRSS Involvement with ITU-R to Address this Issue","authors":"P. de Matthaeis, D. Draper, J. Johnson, Steen Savstrup Krinstensen, Y. Soldo, T. Von Deak, Mohammad M. Al-Khaldi, R. Shah","doi":"10.23919/RFI48793.2019.9111824","DOIUrl":"https://doi.org/10.23919/RFI48793.2019.9111824","url":null,"abstract":"The 18.6–18.8 GHz band is utilized extensively for scientific uses. Passive microwave measurements in this frequency range are critical for weather forecasting and studies of climate and environmental impacts. This band, however, is shared with commercial communication systems that operate under the Fixed Satellite Service (FSS). FSS communication is used mostly for satellite TV broadcasting, and by a small number of Very Small Aperture Terminal (VSAT) systems. The Radio Regulations of the International Telecommunication Union (ITU) limit the level of FSS transmitted powers in order to avoid interference to passive sensors that operate under the Earth Exploration Satellite Service (EESS). However, Radio Frequency Interference (RFI) affecting spaceborne microwave radiometers such as WindSat, AMSR2 and GPM-GMI at 18 GHZ has been observed and documented for several years since 2010. Calculations considering sea surface reflection show that the observed RFI is consistent with or higher than what could be expected even from the limited level of transmitted power from the FSS. The IEEE Geoscience and Remote Sensing Society (GRSS) has brought this problem to the attention of the ITU Radiocommunication Sector (ITU-R) Study Groups, in view of impending decisions that could potentially dramatically increase the use of this band by commercial operators. The contributions by IEEE GRSS to ITU-R will be presented and various issues involved will be discussed.","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127336416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lessons Learnt from SMOS RFI Activities After 10 Years in Orbit: RFI Detection and Reporting to Claim Protection and Increase Awareness of the Interference Problem in the 1400–1427 MHZ Passive Band","authors":"Á. Llorente, E. Daganzo, R. Oliva, Ekhi Uranga, Y. Kerr, P. Richaume, Antonio de la Fuente, M. Martín-Neira, S. Mecklenburg","doi":"10.23919/RFI48793.2019.9111797","DOIUrl":"https://doi.org/10.23919/RFI48793.2019.9111797","url":null,"abstract":"The European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) mission is perturbed by Radio Frequency Interference (RFI) that jeopardizes part of its scientific retrieval in certain areas of the world. Areas affected by RFI experience data loss or underestimation of soil moisture and ocean salinity retrieval values. Close to the 10th anniversary of SMOS launch, this paper provides an overview of SMOS RFI activities during these years, the evolution of the RFI scenario worldwide and the lessons learned. The main challenges faced in the RFI detection and geo-location will be introduced, with some interesting examples of RFI cases detected. Another topic addressed in this paper is the impact of the RFI contamination from a scientific perspective, with some estimations of the data percentage that has to be discarded due to interference.","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"2002 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128798547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Digital Beamforming Based RFI Extraction for an On-Ground Correction of Synthetic Aperture Radar Data","authors":"T. Bollian, M. Younis, G. Krieger","doi":"10.23919/RFI48793.2019.9111730","DOIUrl":"https://doi.org/10.23919/RFI48793.2019.9111730","url":null,"abstract":"Radar remote sensing instruments have played an increasingly important role in understanding Earth and its dynamic processes. Their operational frequencies are predetermined based on the physical properties that are to be retrieved. Simultaneously, the use of their allocated frequency bands in P- to C-band by other services has increased. A reliable mitigation of Radio Frequency Interference (RFI) is therefore critical for future Earth observation missions.New space-borne multi-channel Synthetic Aperture Radar (SAR) instruments are capable of Digital Beamforming (DBF). Each receive channel is recorded individually to form the digital antenna pattern after data acquisition. This opens up new opportunities for spatial RFI filtering. Unfortunately, this approach requires significant processing power on board the satellite as it is unfeasible to downlink the increased data volume. This paper presents a new method based on auxiliary beams that relaxes the requirement for the on-board processing power and only affects the downlinked data volume minimally. The information measured with the auxiliary beam can be used for an on-ground RFI correction.","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123633804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Edge-Thresholding: A New Thresholding Based Real-Time RFI-Mitigation Algorithm for Transient Detection","authors":"J. Boyle, A. Sclocco","doi":"10.23919/RFI48793.2019.9111722","DOIUrl":"https://doi.org/10.23919/RFI48793.2019.9111722","url":null,"abstract":"Unraveling the mystery of fast radio bursts (FRBs) - extremely high-energy events occurring outside the Milky Way that last fractions of a second - is a hot topic topic in radio astronomy. Detecting new FRBs is increasingly complicated by RFI as the radio bandwidth becomes more congested and radio telescopes become more sensitive. In this paper we propose, implement and validate a novel RFI-mitigation algorithm designed for FRB detection called edge-thresholding.Modern radio telescopes produce an immense amount of data that needs to be processed in real-time. This requirement invalidates many RFI-mitigation algorithms based upon techniques such as kurtosis, surface-fitting or Fourier transforms due to their computational complexity. This had led to the development of thresholding methods which are computational simple, well suited to GPU acceleration and provide accurate RFI mitigation.In this paper we propose edge-thresholding, the first thresholding based RFI-mitigation algorithm specifically designed for FRB detection. Edge-thresholding works by flagging data within a window if the points minimum difference to a boundary point is above a computed threshold. Linear time-complexity means it scales to the increasing data rates of radio telescopes.Edge-thresholding takes advantage of two features that FRBs exhibit but RFI does not. First, FRBs are generally wider than deleterious RFI and second FRBs have a pseudo Gaussian profile due to the finite frequency resolution of the telescope causing DM smearing.We combine edge-thresholding with a time-domain sigma cut in a unified pipeline. A GPU accelerated implementation of this pipeline is shown to run in the real-time on WSRT data. Additionally, less than 36.86 additional kilobytes of memory are required for 804 megabytes of input data.Using data from WSRT containing simulated FRBs we shown that our pipeline reduces false-positives and increases the number of detected FRBs. These results are further validated by experiments using data from the Crab-Pulsar. These results show that our pipeline could outperform AO-Flagger, the RFI-mitigation pipeline used for WSRT and LOFAR.","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130852791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of RFI and RFI Mitigation Techniques in SKA1 Mid Telescope","authors":"T. Gunaratne, A. Peens-Hough","doi":"10.23919/RFI48793.2019.9111712","DOIUrl":"https://doi.org/10.23919/RFI48793.2019.9111712","url":null,"abstract":"Radio Frequency Interference (RFI) has become a great challenge for the highly sensitive next-generation radio telescopes such as the Square Kilometre Array (SKA). The SKA phase-1 Mid frequency (SKA1-Mid) telescope is exposed to RFI from aeronautical navigation and satellite broadcasting and navigation, although, it is generally protected from terrestrial RFI being located in a radio-quite zone in South Africa. An earlier study was conducted to model the RFI that is expected by the receivers of SKA1-Mid at the Karoo site. This is further extended to study, through modelling, the responses of the receiver’s analog signal chain and the correlator and beamformer’s digital signal processing chain along with the RFI mitigation techniques proposed for the SKA1-Mid telescope. Simulations have been conducted to confirm that the stringent requirements, which needed to meet the science goals of the telescope, can be met under several RFI scenarios.","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115660268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RFI 2019 TOC","authors":"","doi":"10.23919/rfi48793.2019.9111828","DOIUrl":"https://doi.org/10.23919/rfi48793.2019.9111828","url":null,"abstract":"","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126932961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclic Imaging for All-Sky Interference Forecasting with Array Radio Telescopes","authors":"G. Hellbourg, I. Morrison","doi":"10.23919/RFI48793.2019.9111786","DOIUrl":"https://doi.org/10.23919/RFI48793.2019.9111786","url":null,"abstract":"Radio Frequency Interference (RFI) is threatening modern radio astronomy. A classic approach to mitigate its impact on astronomical data involves discarding the corrupted time and frequency data samples through a process called flagging and blanking. We propose the exploitation of the cyclostationary properties of the RFI signals to reliably detect and predict their locations within an array radio telescope field-of-view, and dynamically schedule the astronomical observations such as to minimize the probability of RFI data corruption.","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121463348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RFI Detection and Mitigation in an sUAS Based L Band Correlation Radiometer for Soil Moisture Measurements","authors":"Aravind Venkitasubramony, E. Dai, A. Gasiewski, M. Stachura, Jack Elston","doi":"10.23919/RFI48793.2019.9111697","DOIUrl":"https://doi.org/10.23919/RFI48793.2019.9111697","url":null,"abstract":"The Lobe Differencing Correlating Radiometer (LDCR) developed at Center for Environmental Technology (CET) at CU, Boulder is a lightweight payload for small unmanned aerial systems (sUAS) enabling remote soil moisture measurement for precision agriculture applications. The second revision of the payload (LDCR Rev B) includes a digital correlation detector for which the data processing flow, instrument calibration, and test data analysis is presented. Cross frequency peak detection, time and frequency domain kurtosis, and complex coherence phase are used to detect radio frequency interference (RFI) in the high spectral resolution radiometric data. A quiescent state performance analysis using matched loads and antennas revealing RFI generated from the radiometer high speed data acquisition system, and the sUAS communication system is discussed.","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121746065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GNSS Interference Cases Handling and the Fight Against the Spread of Illegal GNSS Jammers by ANFR, the French Spectrum Management and Monitoring Authority","authors":"Catherine Gabay","doi":"10.23919/RFI48793.2019.9111778","DOIUrl":"https://doi.org/10.23919/RFI48793.2019.9111778","url":null,"abstract":"With the ever-growing use of GNSS (Global Navigation Satellite Systems, like GPS, Galileo and Glonass) signals by public and safety services, research and scientific activities and economic sectors for positioning and timing services, the issue of radio frequency interference (RFI) affecting GNSS signals is becoming increasingly critical. In the meanwhile, GNSS jammers are easy to buy, notably on e-commerce web sites.In this context, ANFR (Agence nationale des fréquences), the French national authority in charge of spectrum planning, management and monitoring regards as very important protecting GNSS frequencies against RFI and fighting the spread of illegal GNSS jammers.General information is given as well as concrete examples of actions undertaken by ANFR. The latter include handling GNSS interference cases on the field, GNSS frequencies band monitoring, spread risk analysis for GNSS jammers, Market Surveillance, Research and Development activities for the detection of GNSS jammers, as well as Communication and Awareness-raising operations to educate the public on the risks of using jammers and the associated criminal penalties.In addition to the French spectrum agency’s experience, this paper includes information on other countries’ practices, through the analysis of a CEPT1 benchmark [1] – [3] conducted by Project Team FM22 (Frequency Monitoring and Enforcement) and Working Group FM (Frequency Management) of the ECC2.","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124503126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RFI 2019 Author Index","authors":"","doi":"10.23919/rfi48793.2019.9111665","DOIUrl":"https://doi.org/10.23919/rfi48793.2019.9111665","url":null,"abstract":"","PeriodicalId":111866,"journal":{"name":"2019 RFI Workshop - Coexisting with Radio Frequency Interference (RFI)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123925772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}