# Purple

> A 12.5 kHz shallow-water channel from the SPACE'08 experiment off Martha's Vineyard, with cross and vertical receiving arrays at ranges from 60 m to 1 km.

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LLMS index: [llms.txt](/llms.txt)

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* Experiment:
  * Location: 41.2N, 70.3W
  * Date recorded: October 2008
  * Center frequency: f<sub>c</sub> = 12.5 kHz
  * Bandwidth: B = 6.6 kHz
  * Symbol rate: R = 10<sup>7</sup>/1536 sym/s (approximately 6.5 ksym/s)
  * Distance: d = 60 m (array 1), 200 m (array 2), and 1 km (array 3)
  * Tx/Rx/water depth: d<sub>T</sub>/d<sub>R</sub>/d<sub>w</sub> = 11 m/10 m/15 m
  * Mobility: moored
  * Receiving array 1: cross, 16 elements in each leg (M = 32 in total), &#8467; = 3.75 cm spacing (numbered top to bottom, then left to right)
  * Receiving array 2: vertical, M = 24 elements, &#8467; = 5 cm spacing (numbered top to bottom)
  * Receiving array 3: vertical, M = 12 elements, &#8467; = 12 cm spacing (numbered top to bottom)
* Parameters:
  * Sampling rate in delay: f<sub>s</sub> = 2R
  * Total delay coverage: up to 27 ms
  * Sampling rate in time: R/100 for the channel response, 2R for the phase/delay
  * Total time coverage: 55 seconds