Rowe Technologies Inc. Long Range Mode

Some may have noticed Teledyne RD Instruments new optional feature XRT (Extended Range Tracking) in there DVL. Well I have great news for all current and future Rowe Technologies ADCP and DVL owners, this feature has been included with all our ADCPs and DVLs from the beginning and it has always been FREE. We have called this mode, Long Range (LR) mode.

Narrowband (Long Range Mode)

Their new XRT feature uses Narrowband processing. Narrowband has its benefits and drawbacks. Narrowband data has a higher variance but 50% greater range compared to Broadband. The optimal setup is to use Narrowband when the depth exceeds the limits of Broadband. Rowe Technologies engineers have developed algorithms in all our ADCP/DVL to automatically switch between Narrowband and Broadband, based off the depth from Bottom Track. On power up the ADCP/DVL will search for the bottom. Based off where it finds the bottom, it will set the optimal settings to maintain a bottom lock. If you are in deep water and the ADCP/DVL choses Narrowband to see the bottom, the ADCP/DVL will then monitor the depth changes and will automatically switch to Broadband mode if the depth is within the range of Broadband. If you travel back into deeper water, the ADCP/DVL will switch back to Narrowband mode seamlessly. When the ADCP/DVL is in Narrowband mode, our ADCP/DVL will output LR (Long Range) mode in the Bottom Track status. This tells the user/software that the ADCP is in Narrowband mode and will have a higher variance in the Bottom Track Range values. When the ADCP/DVL is in Broadband mode, our ADCP/DVL will output GOOD in the Bottom Track status.

At any time, you can configure the ADCP/DVL to remain only in Broadband mode or Narrowband mode. And the switching points can also be configured if you want to fine tune the transition between Broadband and Narrowband. MORE DETAIL

Our Narrowband (LR) processing has been tested and enhanced for many years to give the best possible results. Below I give some examples of the enhancements over the years of our Long Range Mode.

At Rowe Technologies, there is no difference between an ADCP and DVL. Our ADCP/DVL all come with the same features, you just select the frequency, how many beams and a housing.

Examples of Transition

In this example I used a 1200khz because you can perfectly see the transition between Narrowband and Broadband from our ADCP/DVL in our local lake. Teledyne advertise for their Navigator a maximum altitude of 25m for their 1200khz. We advertise that our ADCP/DVL has a maximum altitude of 50m from our 1200khz. Our lake is about 27m depending on the water level for the day. It will vary, because the lake is also used as reservoir for drinking.

Transition from Narrowband (30m) to Broadband (20m)
2018 - 1200khz ADCP\DVL Lake data Narrowband Bottom Track (LR) transitioned to Broadband automatically. Even in Narrowband (LR) mode, the data is tight together. As the years have passed, our engineers have enhanced the Narrowband processing. Throughout this travel, the ADCP/DVL saw the bottom and the ranges matched closely between all the beams.
2015 - 1200khz ADCP\DVL Lake data Narrowband Bottom Track (LR) transitioned to Broadband automatically. During this run, we see the Narrowband have some lost bottom lock in Narrowband. The straight lines indicate where there was no bottom lock.
2014 - 1200khz ADCP\DVL Lake data Older processing of Narrowband Bottom Track (LR) transitioned to Broadband automatically. Our first iteration with Narrowband and automatically switching. The Narrowband was available but had a high variance. Our engineers have improved the Narrowband processing over the years in our ADCP/DVL.
Data zoomed into 20m - 26m
2018 - 1200khz ADCP\DVL Lake data Narrowband Bottom Track (LR) zoomed into 20m-26m. As the years have passed, our engineers have enhanced the Narrowband processing. The bottom is found throughout the data collection in Narrowband mode.
2015 - 1200khz ADCP\DVL Lake data Narrowband Bottom Track (LR) zoomed into 20m-26m. The straight lines occur when bottom lock was lost.