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== Hardware & instrument configuration  considerations ==
== Hardware & instrument configuration  considerations ==


# Available Power and Storage ​
# Environmental conditions
#: What battery pack equivalent you have, what storage you have ​
## Ensure velocity range is sufficient for anticipated background flow, tides, surface waves and internal waves
## Select spatial range (number of bins and bin size) consistent with eddy inertial range Ozmidov length given anticipated stratification and turbulence levels
# Velocity measurements
## Record in Beam coordinates​
## Maximise velocity accuracy whilst minimising averaging (pings per ensemble)
## Select <math>\varepsilon<\math> estimate observation period (period over which structure function is evaluated) consistent with fundamental requirement of stationary statistics
## Maximise the number of profiles (ensembles) per <math>\varepsilon<\math> estimate observation period to improve statistics
# Motion control​ during deployment
# Motion control​ during deployment
## Sufficient buoyancy on frame to hold position well, but not obstructing beam path ​
## Sufficient buoyancy on frame to hold position well, but not obstructing beam path ​
## Consider also nearby moorings and frames to reduce/avoid interference.
## Consider also nearby moorings and frames to reduce/avoid interference.
## If moving mooring, collect all heading, pitch and roll data. Consider high resolution add on’s such as AHRS. ​
## If the mooring can move, collect depth (pressure sensor on ADCP or adjacent instrument) and orientation data (heading, pitch and roll) at the same frequency as the velocity profiles data. Consider high resolution add-on’s such as AHRS. ​
## Estimate movement and knock-down and thus proportion of data valid points – weigh up sampling regime, appropriateness of instrument​
## Mooring design should consider impact of knock-down on location of observations in the water column
## require pressure sensor (on ADCP or nearby instrument) for mid-water deployments on moving moorings.​
# Beam coordinate setup​
## Record in Beam coordinates​
## Vertical beam in different mode such as alternating high resolution repetition rate?​
## Vertical beam in different mode such as alternating high resolution repetition rate?​
# Range of measurement​
# Power and Storage ​for self-contained deployments
## Hardware/configuration but environmental considerations such as stratification​
## Planned deployment duration
# Eddy sizes/overturn size​:
## Manufacturer’s expected energy consumption versus battery capacity at expected temperature
## Number of profiles per observation burst and burst duration relative to forcing processes – assumption of statistical constancy over the burst period.​
## Manufacturer’s expected memory required per recorded profile (ensemble) versus available memory
## Estimate max overturn size, to later set maximum radial separation parameter (r_max or max_rads)
# Consistent statistics (frozen field) assumption​
# playing with the number of bins.. you ‘might’ get more range.. but at the expense of storage and power.. and you might not get any more data due to range limitations
 


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Revision as of 12:19, 9 November 2021

Hardware & instrument configuration considerations

  1. Environmental conditions
    1. Ensure velocity range is sufficient for anticipated background flow, tides, surface waves and internal waves
    2. Select spatial range (number of bins and bin size) consistent with eddy inertial range Ozmidov length given anticipated stratification and turbulence levels
  2. Velocity measurements
    1. Record in Beam coordinates​
    2. Maximise velocity accuracy whilst minimising averaging (pings per ensemble)
    3. Select <math>\varepsilon<\math> estimate observation period (period over which structure function is evaluated) consistent with fundamental requirement of stationary statistics
    4. Maximise the number of profiles (ensembles) per <math>\varepsilon<\math> estimate observation period to improve statistics
  3. Motion control​ during deployment
    1. Sufficient buoyancy on frame to hold position well, but not obstructing beam path ​
    2. Consider also nearby moorings and frames to reduce/avoid interference.
    3. If the mooring can move, collect depth (pressure sensor on ADCP or adjacent instrument) and orientation data (heading, pitch and roll) at the same frequency as the velocity profiles data. Consider high resolution add-on’s such as AHRS. ​
    4. Mooring design should consider impact of knock-down on location of observations in the water column
    5. Vertical beam in different mode such as alternating high resolution repetition rate?​
  4. Power and Storage ​for self-contained deployments
    1. Planned deployment duration
    2. Manufacturer’s expected energy consumption versus battery capacity at expected temperature
    3. Manufacturer’s expected memory required per recorded profile (ensemble) versus available memory

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