Verschwinden die Bibliotheken im Internet?: Podiumsdiskussion zur Zukunft der Bibliotheken im Kulturzentrum TIETZ in Chemnitz

Wenn es um die Finanzierung von Bibliotheken geht, verwenden die Unterhaltsträger der Bibliotheken oft das Argument, dass Bibliotheken zunehmend an Bedeutung verlieren, weil das Internet ja alle Informationen und digitale Medien bietet. Gern werden aus diesem Grund Mittel gekürzt. Ob dieses Argument stimmt, diskutierten Vertreter aus unterschiedlichen Bereichen des öffentlichen Lebens am 23. April 2015, dem Welttag des Buches, im TIETZ. Die Stadt Chemnitz und die Technische Universität Chemnitz hatten zu dieser Veranstaltung eingeladen, die unter der Schirmherrschaft des Landesverbandes Sachsen des Deutschen Bibliotheksverbands stand. Der Chemnitzer Kulturbürgermeister Philipp Rochold eröffnete die Diskussionsrunde

Sentinel-1 Imaging Performance Verification with TerraSAR-X

This paper presents dedicated analyses of TerraSAR-X data with respect to the Sentinel-1 TOPS imaging mode. First, the analysis of Doppler centroid behaviour for high azimuth steering angles, as occurs in TOPS imaging, is investigated followed by the analysis and compensation of residual scalloping. Finally, the Flexible-Dynamic BAQ (FD-BAQ) raw data compression algorithm is investigated for the first time with real TerraSAR-X data and its performance is compared to state-of-the-art BAQ algorithms. The presented analyses demonstrate the improvements of the new TOPS imaging mode as well as the new FD-BAQ data compression algorithm for SAR image quality in general and in particular for Sentinel-1

Sentinel-1 FDBAQ Performance Validation Using TerraSAR-X Data

Two Block Adaptive Quantization (BAQ) algorithms considered for implementation on-board Sentinel-1, the Entropy Constrained BAQ (ECBAQ) and the Flexible Dynamic BAQ (FDBAQ) are investigated with real data acquired by TerraSAR-X. The two algorithms are compared with respect to the resulting signal-to-quantization-noise ratio (SQNR) and the compression rate. The results confirm the improved performance of FDBAQ to be expected for Sentinel-1 compared to the more conventional ECBAQ

TN 5: Sentinel-1 FDBAQ performance demonstration with TerraSAR-X Algorithm Implementation

In this document, two Block Adaptive Quantization (BAQ) algorithms, the Entropy Constrained BAQ (ECBAQ) and the Flexible Dynamic BAQ (FDBAQ) will be investigated. The software development of both algorithms will be discussed for using TerraSAR-X testdata and a comparison is given regarding the resulting Signal-to-Quantization- Noise-Ratio SQNR, the compression rate as well as the weak target suppression

Verschwinden die Bibliotheken im Internet?: Podiumsdiskussion zur Zukunft der Bibliotheken im Kulturzentrum TIETZ in Chemnitz

Wenn es um die Finanzierung von Bibliotheken geht, verwenden die Unterhaltsträger der Bibliotheken oft das Argument, dass Bibliotheken zunehmend an Bedeutung verlieren, weil das Internet ja alle Informationen und digitale Medien bietet. Gern werden aus diesem Grund Mittel gekürzt. Ob dieses Argument stimmt, diskutierten Vertreter aus unterschiedlichen Bereichen des öffentlichen Lebens am 23. April 2015, dem Welttag des Buches, im TIETZ. Die Stadt Chemnitz und die Technische Universität Chemnitz hatten zu dieser Veranstaltung eingeladen, die unter der Schirmherrschaft des Landesverbandes Sachsen des Deutschen Bibliotheksverbands stand. Der Chemnitzer Kulturbürgermeister Philipp Rochold eröffnete die Diskussionsrunde

Verschwinden die Bibliotheken im Internet?: Podiumsdiskussion zur Zukunft der Bibliotheken im Kulturzentrum TIETZ in Chemnitz

Wenn es um die Finanzierung von Bibliotheken geht, verwenden die Unterhaltsträger der Bibliotheken oft das Argument, dass Bibliotheken zunehmend an Bedeutung verlieren, weil das Internet ja alle Informationen und digitale Medien bietet. Gern werden aus diesem Grund Mittel gekürzt. Ob dieses Argument stimmt, diskutierten Vertreter aus unterschiedlichen Bereichen des öffentlichen Lebens am 23. April 2015, dem Welttag des Buches, im TIETZ. Die Stadt Chemnitz und die Technische Universität Chemnitz hatten zu dieser Veranstaltung eingeladen, die unter der Schirmherrschaft des Landesverbandes Sachsen des Deutschen Bibliotheksverbands stand. Der Chemnitzer Kulturbürgermeister Philipp Rochold eröffnete die Diskussionsrunde

Universitätsbibliothek und Stadtbibliothek Chemnitz: Eine starke Partnerschaft für Bildung, Wissenschaft und lebenslanges Lernen

Als die Stadtbibliothek Chemnitz 2004 aus dem Gebäude der Alten Aktienspinnerei ausgezogen war, wurde es still um das Haus am Rande des Chemnitzer Stadtzentrums. Dann entstand die Idee, die Universitätsbibliothek Chemnitz in diesem Gebäude unterzubringen und nun laufen schon die Planungen für den Umbau des Gebäudes als innerstädtische zentrale Universitätsbibliothek auf Hochtouren (vgl. BIS 2012/3, S. 167–169). Ein Gebäude, die Alte Aktienspinnerei, beherbergt im Laufe seiner Geschichte zwei Bibliotheken. Gibt es außer dieser Tatsache noch mehr, was diese Bibliotheken verbindet? [...

TOPS Image Quality and Processor Verification Study - Final Report

This is the final report summarizing all the activities performed by the German Aerospace Center (DLR), Microwaves and Radar Institute (HR), within the framework of the “TOPS Image Quality and Processor Verification Study” under ESA/ESTEC contract number 22243/09/NL/JA. The main mode of operation for ESA’s Sentinel-1 SAR system is the so-called TOPS (Terrain Observation with Progressive Scan) mode which provides large swath observations with enhanced image performance compared to the traditional ScanSAR mode. In a precursor ESA study performed by DLR-HR (C20679/07/NL/CB “Sentinel-1 TOPS Imaging Mode Demonstration with TerraSAR-X”) the feasibility of this new mode has first been demonstrated evaluating experimental TOPS acquisitions of the German TerraSAR-X satellite TSX. The purpose of the present study is to investigate in more detail specific properties of the new TOPS mode to evaluate whether the ambitious requirements of the S-1 products can be ensured by the present TOPS system design and to identify additional compensation strategies, wherever required. For this purpose several experimental TerraSAR-X acquisitions were scheduled manually and investigated subsequently. The study is divided into four major parts: Chapter 1 investigates two technical questions relating to the TOPS mode of operation. First the problem of Doppler centroid variations at high azimuth steering angles is evaluated as a function of swath width and terrain topography. For this purpose several TSX stripmap acquisitions where scheduled with high azimuth steering angles of 1 deg. The question to be addressed was to identify any possible precautions to be taken in the processor for optimum focussing quality. The second problem relates to the residual scalloping correction which is induced by the electronic antenna steering during acquisition of each TOPS burst. Dedicated TSX TOPS data takes were commanded over Amazonian rainforest and were evaluated for the purpose of defining suitable scalloping correction methods. The second chapter relates to the investigation of particular signal properties of the TOPS mode, specifically with respect to interferometric applications. The azimuth variant Doppler centroid within each burst leads to increased coregistration requirements, which have been quantified and verified using interferometric data sets acquired by TSX in TOPS mode. Time series evaluations of TSX descending Mexico City acquisitions were used to assess and confirm for the first time the suitability of TOPS data for subsidence mapping together with a characterisation of coherent scatterers (CS) for the TOPS mode. The phenomenon of flashing fields has been investigated for the TOPS burst overlay areas using a second time series acquired over Flevoland. Chapter 3 is dedicated to the validation of the operational TOPS processing algorithm. Simulated Sentinel-1 and TerraSAR-X raw data scenarios were defined resulting in the commanding and acquisition of real TerraSAR-X raw data. The processing results of both processors under investigation, i.e. the Sentinel-1 prototype TOPS (SPT) processor and the experimental TerraSAR-X TOPS processor (ETT) were compared. Finally, chapter 4 investigates the innovative Flexible-Dynamic Block Adaptive Quantization (FDBAQ) algorithm for the first time with real spaceborne SAR data. FDBAQ is implemented operationally onboard S-1 to ensure improved data quantization in terms of Signal to Quantization Noise (SQNR) and more efficient data quantization. Dedicated data acquisitions were performed by TSX in stripmap mode, switching off the default onboard BAQ compression. FDBAQ compression results were assessed and compared to the less performing Entropy Coded BAQ (ECBAQ). For each of the investigated topics conclusions are drawn and recommendations for Sentinel-1 are given were appropriate

Extracellular vesicle measurements with nanoparticle tracking analysis – An accuracy and repeatability comparison between NanoSight NS300 and ZetaView

The expanding field of extracellular vesicle (EV) research needs reproducible and accurate methods to characterize single EVs. Nanoparticle Tracking Analysis (NTA) is commonly used to determine EV concentration and diameter. As the EV field is lacking methods to easily confirm and validate NTA data, questioning the reliability of measurements remains highly important. In this regard, a comparison addressing measurement quality between different NTA devices such as Malvern’s NanoSight NS300 or Particle Metrix’ ZetaView has not yet been conducted. To evaluate the accuracy and repeatability of size and concentration determinations of both devices, we employed comparative methods including transmission electron microscopy (TEM) and single particle interferometric reflectance imaging sensing (SP-IRIS) by ExoView. Multiple test measurements with nanospheres, liposomes and ultracentrifuged EVs from human serum and cell culture supernatant were performed. Additionally, serial dilutions and freeze-thaw cycle-dependent EV decrease were measured to determine the robustness of each system. Strikingly, NanoSight NS300 exhibited a 2.0–2.1-fold overestimation of polystyrene and silica nanosphere concentration. By measuring serial dilutions of EV samples, we demonstrated higher accuracy in concentration determination by ZetaView (% BIAS range: 2.7–8.5) in comparison with NanoSight NS300 (% BIAS range: 32.9–36.8). The concentration measurements by ZetaView were also more precise (% CV range: 0.0–4.7) than measurements by NanoSight NS300 (% CV range: 5.4–10.7). On the contrary, quantitative TEM imaging indicated more accurate EV sizing by NanoSight NS300 (% DTEM range: 79.5–134.3) compared to ZetaView (% DTEM range: 111.8–205.7), while being equally repeatable (NanoSight NS300% CV range: 0.8–6.7; ZetaView: 1.4–7.8). However, both devices failed to report a peak EV diameter below 60 nm compared to TEM and SP-IRIS. Taken together, NTA devices differ strongly in their hardware and software affecting measuring results. ZetaView provided a more accurate and repeatable depiction of EV concentration, whereas NanoSight NS300 supplied size measurements of higher resolution