What is RoxAnn Stereo?
RoxAnn Stereo is a variant of Roxann Hydrographic. It has an electronic hardware system which acts as a 'black box' taking as its input the received signals from two echosounder transducers, processing these and outputting digital data to a computer.
How many Component Parts are there?
RoxAnn has one main box which contains the processors and a two smaller boxes which contain the 'head-amplifiers' which matches the echosounder type and frequency.
How is it connected?
RoxAnn has three cables.
- Power Input (AC or DC).
- Echosounder cable which is a two-core individually screened cable which connects across the transducer cable.
- RS232 from RoxAnn to computer.
Does connection of RoxAnn affect the echosounder?
No, the high impedance head amplifier imposes virtually no load on the received signal.
What echosounders will RoxAnn work with?
Virtually all of them. Some old echosounders (20 + years), which do not have stable output power or pulse width to provide difficulties. However most modern echosounders, which are crystal controlled are perfectly suitable for RoxAnn.
What are the Frequency Ranges of echosounders for RoxAnn Stereo operation?
A low frequency echosounder of no greater than 28kHz, with a powerful transmitter and a high frequency echosounder of no less than 200kHz.
What is the difference in operation between frequencies and are RoxAnn results different at different frequencies?
At low frequency (28 kHz and below), soft materials are penetrated to "find" the harder substrate. The high frequency transmissions reflect the softer upper layer.
This is the reason for using this product. The results will indicate not only substrate, but also depth of softer sediment.
What echosounders are commonly used?
Hign frequency - echosounders are those made by Atlas Elektronik, Simrad, Odom, Knudsen, Innerspace, Raytheon,Navitronic, Marimatech, etc.
Low frequency - powerful sounders used in the fishing industry are preferred, like Furuno, Koden, etc.
Is Beam Width important?
Yes - We have seen best results with narrow beams - less than 20 degrees.
Is RoxAnn limited to any range?
Yes - that which is imposed by the high frequency echosounder, although the RoxAnn will continue to operate as a standard system into deeper waters using the low frequency "channel" of the RoxAnn Stereo
Does RoxAnn require a constant transmit pulse?
Yes - RoxAnn takes it's results from the acoustic response of the seabed of the transmit pulse. Pulse width and transmit power must be constant. It's not a special request. All the above echosounder manufacturers provide this as standard.
Does varying the 'gain' on the echosounders affect RoxAnn?
No - this is a function for the receiver stage of an echosounder which is unaffected by RoxAnn and equally does not affect RoxAnn.
Is the Power Supply for RoxAnn important?
Standard ships supply is normally good enough. However care must be taken when fitting to noisy supplies or those prone to excessive voltage levels.
What does RoxAnn Output?
From both of the two RoxAnn channels, an RS232 ports RoxAnn outputs an ASCII data string comprising depth, first echo and second echo.
What Controls does RoxAnn Stereo have?
On the Front Panel of RoxAnn there are no controls. There are 3 switches on the rear of RoxAnn, which are used at installation but not during operation.
How long does it take to install?
Depending on the vessel from 2 hours to 1 day.
Is specialised equipment required?
No.
What skills are required?
The ability to use a soldering iron and perhaps a little carpentry!
At Installation is there a calibration required?
Yes - This is because every echosounder, transducer and installation is different and RoxAnn must be set-up to take account of these differences. In effect, calibration is achieved by taking the vessel to open water and pressing the 'calibration' switch on the rear panel of the RoxAnn.
How often do I have to calibrate?
Once.
After Calibration are the results lost when power is removed?
Battery pack up provides calibration for around 12 months. In the interim period, calibration may be 'locked in'. This is done by following a simple procedure with no specialist tools - only a screwdriver and multimeter.
After Installation, how do I know RoxAnn is working?
Two 'Leds' on the front panel provide 'at a glance Q.C' of the system. If they are equally bright, then RoxAnn is operating well.
What does the computer do?
The computer which receives the output from RoxAnn Stereo, runs the software which collects, saves, displays and processes results from RoxAnn.
What are these results?
For each of the pulses at high and low frequency - Depth, first echo (E1), second echo (E2).
What is E1?
E1 is a digital indicator of seabed roughness. The lower the value the smoother the material, the higher the value the rougher the material.
What is E2?
E2 is a digital indicator of seabed hardness. The lower the number, the softer the material; the higher the number, the harder the material.
Where are E1 and E2 derived?
E1 is derived from the first (main) echo from the echosounder transmission. E2 is derived from the second (first multiple) echo.
Why is RoxAnn unique?
The technique for deriving roughness and hardness from E1 and E2 is patented on a world-wide basis, following invention of RoxAnn in 1980.
Does RoxAnn have pitch and roll stability?
Yes, but not in the usual manner of using a pitch and roll sensor compensation. One of the printed circuit boards in RoxAnn is the Gimbal PCB. This provides for levelling of non-vertical transmission pulse, thus allowing RoxAnn to output at varying sea-states.
How are RoxAnn results displayed?
RoxAnn results are combined with positioning data from a (D)GPS and are plotted on a chart. The only software package with an interface for RoxAnn Stereo is RoxMap. It has been written to collect the simultaneous data from the two channels, store them on a database and display as a three dimensional model.
What types of Materials have been identified by RoxAnn?
This list shows the variety of materials that have been identified by RoxAnn:
Algae's, Burnt Oil Residue, Clay Non-Cohesive, Coal, Coarse Sand, Cohesive Clay, Corals, Crabs, Crayfish, Debris, Drilling Cuttings, Drilling Fluids, Eel Grass, Fine-Sand, Gravel, Gravel/Clay Substrate, Lobsters, Molluscs, Mud, Mussels, Oil Residue, Patch Reef, Pipelines, Rock, Flat Rock, Rough Rock, Bed Rock, Scallops, Sea Urchins, Seagrass-dying, dead, mature, new growth, Searmarl, Seaweed, Silt, Starfish, Trees & Logs (Underwater), Weathered Rock, Weed Densities, Weed on Rock, Wrecks.
What industries use RoxAnn?
The following list gives an indication as to the variety of industries that RoxAnn can be used in so far:
Biological Monitoring, Crayfish, Debris Clearance, Defence, Diamond Hunting, Dredging Environmental Control, Fisheries Research, Fishing, Ground Fisheries, Hydrographic, Lobster Fisheries, Mine Counter Measures, Mapping, Mineral Resource, Monitoring, Oil Industry, Oil Spill Response, Pelagic Fisheries, Pipeline Route Surveys, Prawn Fisheries, Shell Fisheries, Surveys, Wreck Hunting.
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