Mark 3 wideband digital recorder in perspective

The tape recorder used for the Mark 3 data acquisition and processing system is compared with earlier very long baseline interferometry recorders. Wideband 33-1/3 kbpi digital channel characteristics of instrumentation recorders and of a modern video cassette recorder are illustrated. Factors which influenced selection of the three major commercial components (transport, heads, and tape) are discussed. A brief functional description and the reasons for development of efficient signal electronics and necessary auxiliary control electronics are given. The design and operation of a digital bit synchronizer is illustrated as an example of the high degree of simplicity achieved

Helical scan recording with a self-acting negative air bearing

A flat head and a tape transport arrangement impart a wrap angle to the tape at the upstream corner of the head. The wrap angle, corner sharpness and tape stiffness are sufficient to cause a moving tape to form a hollow bump at the upstream corner, thereby creating a hollow into which entrained air can expand, causing a subambient pressure within and downstream of the bump. This pressure keeps the tape in contact with the head. It is created without the need for a groove or complex pressure relief slot(s). No contact pressure arises at the signal exchange site due to media wrap. The highest contact pressures are developed at a wrapped upstream corner. For a tape drive, traveling in both forward and reverse, the wrap can be at both the upstream and downstream (which is the reverse upstream) corners. Heads that are not flat can also be used, if the wrap angle relative to a main surface is sufficient and not too large. The wrapped head can also be used with rotating media, such as disks (floppy and hard) and rotating heads, such as helical wound heads for video recording. Multiple flat tape bearing surfaces can be separated by grooves and/or angles. Each flat can carry heads along one or more gap lines. Multiple adjacent narrow tracks can thus be written for extreme high track density recording

High data rate recorder development at MIT Haystack Observatory

Current operational capabilities of tape recording for Very Long Baseline Interferometry (VLBI) at the Haystack Observatory allow 0.7 terabytes (12 hours at 128 Mb/s) of data to be stored in a 128 cu. inch volume. On-going efforts are aimed at full time 1 Gb/s operation with two 36-channel headstacks. Applications for linear digital tape recording, with suitable development of thin-film head arrays, suggest a volume density exceeding 1 TB/cu. inch to be achievable in the future

Contact sheet recording with a self-acting negative air bearing

A flat head and a tape transport arrangement impart a wrap angle to the tape at the upstream corner of the head. The wrap angle, corner sharpness and tape stiffness are sufficient to cause a moving tape to form a hollow bump at the upstream corner, thereby creating a hollow into which entrained air can expand, causing a subambient pressure within and downstream of the bump. This pressure keeps the tape in contact with the head. It is created without the need for a groove or complex pressure relief slot(s). No contact pressure arises at the signal exchange site due to media wrap. The highest contact pressures are developed at a wrapped upstream corner. For a tape drive, traveling in both forward and reverse, the wrap can be at both the upstream and downstream (which is the reverse upstream) corners. Heads that are not flat can also be used, if the wrap angle relative to a main surface is sufficient and not too large. The wrapped head can also be used with rotating media, such as disks (floppy and hard) and rotating heads, such as helical wound heads for video recording. Multiple flat tape bearing surfaces can be separated by grooves and/or angles. Each flat can carry heads along one or more gap lines. Multiple adjacent narrow tracks can thus be written for extreme high track density recording

Automatisierte Identifikation von Baulücken und Nachverdichtungspotenzialen im Wohnungsbau

Das Forschungsziel war es, die automatisierte Identifikation von Nachverdichtungspotenzialen und Baulücken zu untersuchen. Als Grundlage dient dabei eine bestehende Studie des Leibniz-Instituts für ökologische Raumentwicklung (IÖR) aus dem Jahr 2013. Die Studie wird dabei auf erkennbare Verbesserungspotenziale untersucht. Ein Verbesserungsvorschlag ist die Identifikation weiterer Arten der Nachverdichtung. Hierbei waren insbesondere die Arten der Aufstockung, des Ersatzneubaus, der Brachflächenidentifikation und der Umnutzung relevant. Auch wurde untersucht, inwiefern ein Abgleich der Ist-Bebauung mit der rechtlich zulässigen Bebauung das bisherige Modell des Überbauungsgrades zur Abschätzung des Nachverdichtungspotenzials ersetzen kann. Schlussendlich wurden weitere Datenquellen auf ihre Eignung zur Verbesserung der Vorhersagegenauigkeit des Systems geprüft. Hierbei waren insbesondere erteilte Baugenehmigungen relevant. Insgesamt hat sich gezeigt, dass sich die Identifikation von Nachverdichtungspotenzialen gut automatisieren lässt. Auch konnten einige Ansätze entwickelt werden, die die Vorhersagegenauigkeit des IÖR-Modells deutlich verbessern. Andererseits sind einige Fehlerquellen, die schon in der ursprünglichen Studie erkannt worden sind, auch heute nicht vollständig automatisierbar