scholarly journals Crowded Space: A Review on Radar Measurements for Space Debris Monitoring and Tracking

2021 ◽  
Vol 11 (4) ◽  
pp. 1364
Author(s):  
Giacomo Muntoni ◽  
Giorgio Montisci ◽  
Tonino Pisanu ◽  
Pietro Andronico ◽  
Giuseppe Valente
Keyword(s):  
Scientific Community ◽  
Space Debris ◽  
Geographical Location ◽  
Radar Measurement ◽  
Radar Systems ◽  
Radar Measurements ◽  
A Priority

Space debris monitoring is nowadays a priority for worldwide space agencies, due to the serious threat that these objects present. More and more efforts have been made to extend the network of available radar systems devoted to the control of space. A meticulous review has been done in this paper, in order to find and classify the considerable amounts of data provided by the scientific community that deal with RADAR measurement for the debris monitoring and tracking. The information gathered is organized based on the volume of found data and classified taking into account the geographical location of the facilities.

scholarly journals Advection-Based Adjustment of Radar Measurements

2012 ◽  
Vol 140 (3) ◽  
pp. 1014-1022 ◽  
Author(s):  
Tuomo Lauri ◽  
Jarmo Koistinen ◽  
Dmitri Moisseev
Keyword(s):  
Elevation Angle ◽  
Geographical Location ◽  
Ground Level ◽  
Limited Area ◽  
Similar Amount ◽  
Radar Measurement ◽  
Wind Climatology ◽  
Radar Measurements ◽  
Nwp Model ◽  
Adjustment Scheme

When making radar-based precipitation products, a radar measurement is commonly taken to represent the geographical location vertically below the contributing volume of the measurement sample. However, when wind is present during the fall of the hydrometeors, precipitation will be displaced horizontally from the geographical location of the radar measurement. Horizontal advection will introduce discrepancies between the radar-measured and ground level precipitation fields. The significance of the adjustment depends on a variety of factors related to the characteristics of the observed precipitation as well as those of the desired end product. In this paper the authors present an advection adjustment scheme for radar precipitation observations using estimated hydrometeor trajectories obtained from the High-Resolution Limited-Area Model (HIRLAM) MB71 NWP model data. They use the method to correct the operational Finnish radar composite and evaluate the significance of precipitation advection in typical Finnish conditions. The results show that advection distances on the order of tens of kilometers are consistently observed near the edge of the composite at ranges of 100–250 km from the nearest radar, even when using a low elevation angle of 0.3°. The Finnish wind climatology suggests that approximately 15% of single radar measurement areas are lost on average when estimating ground level rainfall if no advection adjustment is applied. For the Finnish composite, area reductions of approximately 10% have been observed, while the measuring area is extended downstream by a similar amount. Advection becomes increasingly important at all ranges in snowfall with maximum distances exceeding 100 km.

scholarly journals The Ad Hoc Back-End of the BIRALET Radar to Measure Slant-Range and Doppler Shift of Resident Space Objects

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 577
Author(s):  
Luca Schirru ◽  
Tonino Pisanu ◽  
Angelo Podda
Keyword(s):  
Doppler Shift ◽  
Space Debris ◽  
Ad Hoc ◽  
Low Earth Orbit ◽  
Slant Range ◽  
Radar Systems ◽  
The Earth ◽  
Space Objects ◽  
Resident Space Objects ◽  
Potential Issue

Space debris is a term for all human-made objects orbiting the Earth or reentering the atmosphere. The population of space debris is continuously growing and it represents a potential issue for active satellites and spacecraft. New collisions and fragmentation could exponentially increase the amount of debris and so the level of risk represented by these objects. The principal technique used for the debris monitoring, in the Low Earth Orbit (LEO) between 200 km and 2000 km of altitude, is based on radar systems. The BIRALET system represents one of the main Italian radars involved in resident space objects observations. It is a bi-static radar, which operates in the P-band at 410–415 MHz, that uses the Sardinia Radio Telescope as receiver. In this paper, a detailed description of the new ad hoc back-end developed for the BIRALET radar, with the aim to perform slant-range and Doppler shift measurements, is presented. The new system was successfully tested in several validation measurement campaigns, the results of which are reported and discussed.

«Love Rejoices in Truth …»: to the 20th anniversary of the journal «Solovyov Studies»

2021 ◽  
pp. 6-24
Author(s):  
M.V. Maksimov
Keyword(s):  
United States Of America ◽  
Scientific Community ◽  
Geographical Location ◽  
The United States ◽  
Information Support ◽  
The Past ◽  
20Th Anniversary ◽  
Student Projects

This essay presents a description of the scholarly events commemorating the 20th anniversary of the journal “Solovyov Studies”. It gives an overview of the exhibition "20 years of the journal “Solovyov Studies”: 2001–2021," prepared by the editorial board of the journal together with the Library of the ISPU. It highlights a variety of the sections of the exposition and the materials presented, reflecting the development of the journal over two decades, the composition of its editorial board, including authoritative experts from Russia, Bulgaria, Great Britain, Germany, Italy, the Netherlands, Poland, the United States of America, Ukraine, and France. The reader’s attention is drawn to the information about the journal's position in various ratings schemes, both domestic and foreign, and citation indices, the share of publications by foreign authors and their geographical location, as well as the number of journal-views over the past five years. The article shows the role of scientific communications in the development of the journal, Information is given on the participation of the editorial board in international scientific events, on publications devoted to the journal and its presentations in Russian and foreign publications, universities and research centers. The article describes the Solovyov seminar’s cultural and student projects, which received substantial content and information support from “Solovyov Studies”. The level of interest of the scientific community in the journal is also noted.

policy statement of the American Meteorological Society on weather radar

1981 ◽  
Vol 62 (5) ◽  
pp. 678-679
Keyword(s):  
Doppler Radar ◽  
Weather Radar ◽  
Digital Processing ◽  
Radar System ◽  
Policy Statement ◽  
Weather Radars ◽  
American Meteorological Society ◽  
Radar Systems ◽  
Technological Advances ◽  
Radar Measurements

Recent technological advances have greatly enhanced the value of weather radar for storm detection, warning, and study. The use of digital computing equipment in association with weather radars now provides techniques for collecting, monitoring, archiving, and presenting the radar measurements in a variety of useful ways and at rates that can keep pace with the acquisition of the data. Developments in Doppler radar technology allow the measurement of air motions (such as tornado vortices) and other features of storm structures. The AMS commends the U.S. Government for its initiative in planning for an advanced weather radar system. The AMS urges governments to place a high priority on the design, procurement, and deployment of the new weather radar systems that incorporate both Doppler and digital processing capabilities.

scholarly journals Ice Hydrometeor Shape Estimations Using Polarimetric Operational and Research Radar Measurements

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 97 ◽  
Author(s):  
Sergey Y. Matrosov
Keyword(s):  
Depolarization Ratio ◽  
Model Uncertainties ◽  
Shape Information ◽  
Ice Cloud ◽  
Cloud Radar ◽  
Weather Radars ◽  
Aspect Ratios ◽  
Radar Systems ◽  
Radar Measurements ◽  
Differential Reflectivity

A polarimetric radar method to estimate mean shapes of ice hydrometeors was applied to several snowfall and ice cloud events observed by operational and research weather radars. The hydrometeor shape information is described in terms of their aspect ratios, r, which represent the ratio of particle minor and major dimensions. The method is based on the relations between depolarization ratio (DR) estimates and aspect ratios. DR values, which are a proxy for circular depolarization ratio, were reconstructed from radar variables of reflectivity factor, Ze, differential reflectivity, ZDR, and copolar correlation coefficient ρhv, which are available from radar systems operating in either simultaneous or alternate transmutation of horizontally and vertically polarized signals. DR-r relations were developed for retrieving aspect ratios and their sensitivity to different assumptions and model uncertainties were discussed. To account for changing particle bulk density, which is a major contributor to the retrieval uncertainty, an approach is suggested to tune the DR-r relations using reflectivity-based estimates of characteristic hydrometeor size. The analyzed events include moderate snowfall observed by an operational S-band weather radar and a precipitating ice cloud observed by a scanning Ka-band cloud radar at an Arctic location. Uncertainties of the retrievals are discussed.

scholarly journals Unified Registration Model for Both Stationary and Mobile 3D Radar Alignment

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Lei Chen ◽  
G. H. Wang ◽  
Ilir F. Progri
Keyword(s):  
Navigation System ◽  
Measurement Errors ◽  
Inertial Navigation System ◽  
Inertial Navigation ◽  
Radar Measurement ◽  
Radar Network ◽  
Radar Measurements ◽  
System Variables ◽  
Analytical Expressions

For mobile radar, offset biases and attitude biases influence radar measurements simultaneously. Attitude biases generated from the errors of the inertial navigation system (INS) of the platform can be converted into equivalent radar measurement errors by three analytical expressions (range, azimuth, and elevation, resp.). These expressions are unique and embody the dependences between the offset and attitude biases. The dependences indicate that all the attitude biases can be viewed as and merged into some kind of offset biases. Based on this, a unified registration model (URM) is proposed which only contains radar “offset biases” in the form of system variables in the registration equations, where, in fact, the “offset biases” contain the influences of the attitude biases. URM has the same form as the registration model of stationary radar network where no attitude biases exist. URM can compensate radar offset and attitude biases simultaneously and has minor computation burden compared with other registration models for mobile radar network.

The Principle of Subsidiarity in the Hague Convention on Intercountry Adoption: A Philosophical Analysis

2019 ◽  
Vol 33 (02) ◽  
pp. 207-230
Author(s):  
Sarah-Vaughan Brakman
Keyword(s):  
Geographical Location ◽  
Hague Convention ◽  
Social Philosophy ◽  
Best Interests ◽  
Intercountry Adoption ◽  
Best Interest ◽  
Conceptual Foundation ◽  
Normative Structure ◽  
Structural Principle ◽  
A Priority

AbstractThe principles of the best interest of children and subsidiarity constitute the conceptual foundation of the Convention on Protection of Children and Co-Operation in Respect of Intercountry Adoption (HCIA). Subsidiarity in the HCIA dictates a priority for domestic adoption placements for children over intercountry adoption. This article argues against subsidiarity on two fronts. First, the analysis shows that the in-principle priority of domestic adoption cannot be justified on the basis of either heritage rights or state sovereignty. Second, the principle of subsidiarity in the HCIA is a procedural principle, one that stipulates the political/geographical location of the placement of children through a priority ordering. This does not comport with the principle of subsidiarity as it has been conceptualized in ethics and social philosophy, which gives normative structure to the process of decision-making by stipulating the proper level for decisional authority. Subsidiarity in this original sense holds that decisions regarding child welfare should be made at the lowest level possible, by those most affected by the decisions, unless doing so would not be the most suited to protecting and promoting the best interests of children. Appealing to subsidiarity in this theoretical version reveals at least two significant problems with HCIA placement policy and leads to the conclusion that subsidiarity in the HCIA must be formally revised as a structural principle of ethics that will not support the general priority of domestic adoption.

scholarly journals MISSILE DEFENSE AND POLISH SECURITY

Politeja ◽  
1970 ◽  
Vol 14 (5 (50)) ◽  
pp. 295-322
Author(s):  
Robert WĘŻOWICZ
Keyword(s):  
Geographical Location ◽  
Compromise Solution ◽  
Defense System ◽  
Missile Defense ◽  
Security Risks ◽  
Air Defense ◽  
System A ◽  
A Priority

MISSILE DEFENSE AND POLISH SECURITY The purpose of the article is to present the multifaceted issue that is missile defense in the context of Polish safety. The fact that Poland is a member of NATO, but also its geographical location and the nature of potential security risks, mean that its position in terms of missile defense is not equivalent to that of other countries. In the case of Poland, we are dealing with plans to create a broadly understood air defense system; a compromise solution, the result of irreconcilable requirements, in which missile defense will be just one of many tasks rather than a priority.

scholarly journals A Statistical Analysis of Rogue Waves in the Southern North Sea

2020 ◽  
Author(s):  
Ina Teutsch ◽  
Ralf Weisse ◽  
Jens Moeller ◽  
Oliver Krueger
Keyword(s):  
North Sea ◽  
Rogue Wave ◽  
Rogue Waves ◽  
New Wave ◽  
Radar Measurement ◽  
Southern North Sea ◽  
Monte Carlo Experiments ◽  
Statistical Sense ◽  
Radar Measurements

Abstract. A new wave dataset from the southern North Sea covering the period 2011–2016 and composed of wave buoy and radar measurements sampling the sea surface height at frequencies between 1.28–4 Hz was quality controlled and scanned for the presence of rogue waves. Here rogue waves refer to waves whose height exceeds twice the significant wave height. Rogue wave frequencies were analysed, compared to Rayleigh and Forristall distributions, and spatial, seasonal and long-term variability was assessed. Rogue wave frequency appeared to be relatively constant over the course of the year and uncorrelated among the different measurement sites. While data from buoys basically correspond with expectations from the Forristall distribution, radar measurement showed some deviations in the upper tail pointing towards higher rogue wave frequencies. Number of data available in the upper tail is, however, still limited to allow a robust assessment. Some indications were found that the distribution of waves in samples with and without rogue waves were different in a statistical sense. However, differences were small and deemed not to be relevant as attempts to use them as a criterion for rogue wave detection were not successful in Monte Carlo experiments based on the available data.

scholarly journals Use of X-Band Radars to Monitor Small Garbage Islands

2021 ◽  
Vol 13 (18) ◽  
pp. 3558
Author(s):  
Francesco Serafino ◽  
Andrea Bianco
Keyword(s):  
Scientific Community ◽  
Research Council ◽  
National Research Council ◽  
Local Scale ◽  
Radar Measurement ◽  
Marine Litter ◽  
Plastic Debris ◽  
Measurement Campaign ◽  
X Band ◽  
Coastal Hydrodynamics

The aim of this work is to verify and demonstrate the possibility of using X-band radars to identify, discriminate, characterize and follow small floating aggregations of marine litter (Small Garbage Islands—SGIs) made up mainly of plastic debris. To this end, a radar measurement campaign was carried out on a series of controlled releases into the sea of SGI modules assembled in the lab using the waste collected along a beach near the port of Livorno, in Tuscany, where the X-band radar of the Institute of Bioeconomy (IBE) of the National Research Council (CNR) is installed. The results of this first measurement campaign, which are illustrated in this preliminary work, are of interest to the entire scientific community that operates in the field of macroplastics analysis and monitoring, opening a new experimental avenue for the use of X-band radars also to monitor plastic waste at sea. Furthermore, the results obtained suggest good prospects for the use of X-band radars also for the study of coastal hydrodynamics on a local scale as well as in areas where it would be difficult to carry out measurements employing other technologies.

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