microRider Turbulence Instrument Package
The microRider is a small instrument package for turbulence microstructure measurements, designed to integrate with a variety of instrument carriers, such as Ocean Gliders, AUV, ROV, CTD rosettes, and profiling floats. For an example of an application on the Slocum glider, please see our news pages at this link.
Several versions of the microRider with different sensor options and depth ratings are available:
| |
mR-500-4 |
mR-1000-6 |
mR-6000-6 |
| Depth Rating |
500 m |
1000 m |
6000 m |
| Shear Probes |
2 |
2 |
2 |
| FP07 Thermistors |
2 |
2 |
2 |
| SBE7 micro-Conductivity |
0 |
1 |
1 |
| Seabird SBE3/SBE4 support |
no |
yes |
yes |
| Data Acquisition |
External (PC104) |
Internal (CF2) |
Internal (CF2) |
All microRider models are externally powered by 9 – 18 VDC, supplied by the supporting vehicle, through one of the connectors on the rear bulkhead of the microRider. Average current draw of the microRider less than 200 mA (@ 15 V).
To improve the signal-to-noise ratio at high frequencies all signal channels are supported by proprietary low-noise signal conditioning circuits. In addition, turbulence sensor channels (shear probe, FP07, micro conductivity) are feature our proprietary Signal-Plus-Signal-Derivative enhancement. Under SPSD signals are differentiated before recording, which enhances signal resolution at higher frequencies. The SPSD is a pre-whitening process akin to the Dolby® Stereo noise reduction system. See our Application note AN-002 for details. The data recording system consists of high-Q anti-aliasing filters (see our Application note AN010 for details) and a low-distortion A/D converter with a linearity of only 15 ppm.
The internal 3D accelerometer pack provides vibration and attitude information. Since the microRider is designed to ride on a wide range of instrumentation platforms, the vibration data are vitally import to the measurement. Platform vibrations that enter the shear probe signals can be removed using coherent signal processing techniques.
For all -1000 and -6000 models, turbulence are recorded internally on an up to 8 GB memory card. The data acquisition is handled by a small computer system (CF2 Persistor) that is integrated inside the pressure case. The data are downloaded via a serial connection, through a bulkhead connector at the rear end cap. The nominal data rate for a standard sensor suite is approximately 40 MB per hour (~ 1 GB per day) at a sampling rate of 512 Hz . The data acquisition can be turned on or off when needed via two control lines on the end cap.
For the -500 model, the data acquisition system is external to the sensor package. The PC104-based DAQ system is integrated into the payload bay of the supporting vehicle.
microRider-500-4 Features
- Remote Data Recording
- 500 m pressure rating
- Up to four turbulence sensors:
- 2x SPM-38-1 microstructure turbulence shear probes;
- 2x FP07-38-1 microstructure fast thermistors;
- 1x High resolution pressure sensor;
- 1x Three-axis, high-accuracy accelerometers for measurement instrument attitude and vibration;
- On-board data acquisition with 4 GB memory (up to 16 GB available);
- High-fidelity signal conditioning using signal derivate technique;
microRider-500-4 dimensions (in inches)
microRider-1000-6 Features
- Internal Data Recording
- 1000 m pressure rating
- Up to five turbulence sensors On/Off indicator
- 2x SPM-38-1 microstructure turbulence shear probes
- 2x FP07-38-1 microstructure fast thermistors
- 1x SBE7-38 microstructure conductivity sensor*
- 1x High resolution pressure sensor;
- 1x Three-axis, high-accuracy accelerometers for measurement instrument attitude and vibration;
- Support for Seabird SBE-3F / SBE-4C WOCE accuracy temperature and conductivity sensor∗;
- Anodized aluminium pressure case rated to 1000 m depth;
- Tapered nose cone to reduce flow deformation from pressure tube;
- On/Off indicator mounted on nose cone;
- On-board data acquisition with 4 GB memory (up to 16 GB available);
- High-fidelity signal conditioning using signal derivate technique.
Download detailed specifications here: microRider_specs.pdf >>>
* optional
microRider-1000-6 dimensions
microRider-6000-6 Features
Most of the specifications are the same as mR-1000-6, except
- High strength aluminium pressure case, titanium end caps and nose cone for 6000m pressure rating
- Face-seals on end caps (instead of piston seals)
- Ability to install 2 micro-Conductivity sensors
- Optional external battery pack for up to 50 hours of operation.
Download detailed specifications here: microRider_specs.pdf >>>