1 Gigabit/sec data recorder

Citation

(1999), "1 Gigabit/sec data recorder", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 1. https://doi.org/10.1108/aeat.1999.12771aad.016

1 Gigabit/sec data recorder

1 Gigabit/sec data recorder

Keywords Avalon, Data selection

Avalon Electronics Ltd introduced a general purpose data recorder with a 1 Gigabit/sec record/replay capability. The maximum data rate achieved by magnetic tape recorders is said to be typically only 500Mbits/sec. Using the latest high speed disk technology, Avalon's new AE7000 CMR (captive media recorder) claims to represent a significant breakthrough in high speed data acquisition, claiming outstanding data integrity with both low capital outlay and negligible operating cost (Plate 3). The new unit is aimed at "high-end" data capture and simulation in intelligence gathering, electronic warfare and similar applications.

Incoming signals are processed and recorded on an array of ten 9.1 GigaByte disks giving a total capacity of 91 GigaBytes (728 Gigabits). Analog signals to a staggering 50MHz, variable rate digital data from 0 to 1 Gigabit/sec plus a variety of commonly used digital communications protocols can all be recorded and replayed directly. The system is able to store up to 19 minutes worth of continuous 622Mbit/sec SONET data or 30 minutes of 20MHz analogue information. Its design also allows for the synchronous operation of several units for even greater bandwidth or mission duration; for example, eight units can be used in parallel to record 1 GigaByte/s.

One of the key advantages claimed by the captive media concept is its SEL (simulated endless loop) recording mode in which data is allowed to be written over earlier redundant signals while awaiting a particular event of interest.

Avalon has initially scheduled the development of standard, interchangeable interfaces covering a range of analogue and digital applications, including DC to 2.5, 20 and 50MHz (analogue), 0 to 1 Gigabit/sec (digital) and the widely used E1, E3, E4, T1, T3, T4, Channel Link, ATM (OC3) and SONET telecommunication standards. Other application specific interfaces will be available either from Avalon or its qualified third part associates.

Plate 3 AE7000 captive media recorder captures digital data at up to 1 Gigabit/s (or analog data to 50MHz)

Avalon's new AE7000 is believed to be a major development in the emerging trend towards "multiplemedia" data capture scenarios in which raw data are captured initially on one storage medium before critical passages are edited and resaved on less sophisticated media for processing or onward transmission.

The unit is housed in a 180 × 445 × 508 mm (7 × 17.5 × 20in.) free-standing, portable or rack mountable case weighing just 15kg (33lb). Internal shock and vibration isolators protect against topple in any axis or a drop of 8in. onto a solid concrete floor, making the unit suitable for a range of in-field data collection tasks. A sophisticated thermal management system ensures proper heat dissipation.

Avalon has identified a number of important applications for the new unit. For example: repeated short term, high frequency events such as radar pulses can be captured in real time before being migrated to an archival recorder such as a DLT (digital linear tape). Alternatively, precise waveforms can be computer-generated and uploaded to the disk array at a relatively slow speed before being replayed through an analogue interface at up to 50MHz to provide simulated signals (also know as arbitrary waveforms) for testing a variety of RF front-ends.

On the data reduction side, the analysis of complex signals frequently calls for the repeated replay during Fourier analysis or correlation. The use of a captive media recorder allows a section of recorded data to be selected and replayed thousands of times without risk of degradation due to the tape wear or costly replacement of scanners associated with conventional high rate data recorders.

But perhaps the most important use is in "post event trigger" (also know as "pre-event") recording where a data source (say the output of an ELINT receiver) is monitored continuously for an event whose arrival time is unpredictable. Traditionally, the only successful means of recording such events was to start a tape recorder early and continue recording for as long as possible, hoping that the event would occur before the tape ended. In this case the AE7000 is used in its SEL mode, continuously storing and updating a period of data determined by the frequency or data rate ­ nearly 20 minutes in the case of 622 Mbit/sec SONET data. Recording can be suspended automatically whenever an event of interest is detected or allowed to continue in a different logical sector of the media.

AE7000 units are available now for demonstration and evaluation while full production units will be available from the first quarter of 1999.

For further details contact Avalon Electronics Ltd. Tel: +44 (0)1749 345266; Fax: +44 (0)1749 345267. E-mail: TMason@avalon-electronics.com; Web:http://www.avalon-electronics.com. Or contact Avalon Electronic, Inc. Tel: +1 (800) 797 1337; Fax: +1 (706) 216 2485; E-mail: avelinc@stc.net