The compact, self-contained Avalon AE9000HW-500 SIGINT Disk Recorder is designed to record, reproduce and export a single channel of wideband analogue IF (intermediate frequency) data at center frequencies of 1 GHz IF or 160 MHz IF at pre-defined bandwidths. Depending on the selected IF, recording bandwidths of up to 500 MHz (1 GHz IF) and 100 MHz (160 MHz IF) are supported.
As shown below, two separate input paths are provided; one for the 1 GHz IF and one for the 160 MHz IF. Each path incorporates input signal conditioning (including gain control) and high-precision anti-alias filtering. When the user selects one of the input paths, the analogue-to-digital converter is automatically programmed to sample the analogue input at the appropriate sample rate (3.3 GHz for the 1 GHz IF and 440 MHz for the 160 MHz IF). The sampling depth for both IFs is 12-bits. 1 GHz IF signals are recorded at 8-bit resolution and 160 MHz IFs are recorded at 16-bit (2 byte) resolution.
The resultant data stream is passed to the DSP block which handles time-stamping, down-conversion (to complex baseband IQ format), data management and writing to the 8 TB (standard) removable disk pack. When the user wishes to record at lower bandwidths, the DSP block also decimates the data stream by the appropriate number of divisions. Data is stored on the disk pack as a series of fixed file-size ‘clusters’, each with a community-standard (Midas Blue) header.
During Playback, the recorded data is up-converted back to its full data rate within the DSP block and then reconstructed into its original full-bandwidth analogue IF form before being passed through the appropriate filtering path. During digital Extract tasks, the DSP block combines the appropriate number of recorded clusters into a single file which is then typically networked to a remote server or other storage device.
