For the past year I have been using the DeepVision DE340 Side Scan Sonar with the DeepView SE software. I have operated DeepVision system in the deep depths of Lake Ontario, the swift waters of the St. Lawrence River and in the murky depths of the Hudson River. The results that we had in each of these very different marine environments were outstanding.
DeepVision has designed the DE340 side scan sonar system with all the features needed to conduct professional geophysical surveys but also made it very affordable for the serious shipwreck enthusiast.
Here are some of the advantages and features that I believe are worthy of consideration.
Views:
The DeepView SE software provides excellent flexibility for viewing sonar scans, nautical maps, and target information. In the Project Mode specific views can be chosen as desired by the operator. These views include: the active scan, magnified view of a scanned target, nautical map, listing of scan files and markers, signal strength over entire range, and an overview of the active scan file. The windows of all of these views can be resized or hidden to suit the preference of the sonar survey operator. Switch to the Scan Mode to view just the active scan or Map Mode to view only the nautical map.
Resolution:
The DE340 side scan system has been designed for high resolution sonar imagery at a frequency of 340 kHz with a range capability of 200 meters (660 ft). At this frequency, DeepVision has designed highly efficient transducers with higher resolution that achieve the same range as other manufactures that are using lower frequencies. Another key factor for the excellent resolution is that the DeepVision towfish has a horizontal beamwidth of only 0.9 degrees. Some of the sonar images that we have obtained were equal or better than those of other sonar systems that offer a 2nd higher frequency in their towfish, but with a very limited range. Excellent high resolution is very important in determining that an underwater target is something worth investigating.
GPS Position:
Integrated into the operation of the DeepVision software is the input of GPS positioning data that is updated every second. The current position of the boat is displayed in the lower left side of the screen and an indication of all of the GPS received satellites is shown in a small a bar graph in the lower right. Placing the cursor anywhere on the screen will provide the exact position on the bottom of a sonar target. Other side scan sonar manufacturers will only provide the boat position down the center of the screen. This feature has been a tremendous asset for us to quickly determine the precise location of underwater targets or interesting bottom features.
Color Mapping Controls:
There are several controls that allow the user to change the scan to one of seven different grayscale color selections. Three color mapping controls allow for incremental adjustment of the slope, black, and white levels of the sonar scans. The appearance of the scan can also be brightened or darkened with the associated control buttons.
Target Analysis Tools:
The Zoom tool provides up to 4X magnification of a scan image.
The Measure Distance tool allows the user to measure the distance in any direction on the sonar scan image or between points on the nautical map.
The Measure Height tool is utilized to determine the height of a target off the bottom with just a few clicks of the mouse.
Marking a Target
When the Marker Mode button is activated each left click of the mouse will add a marker in both the sonar scan and nautical map. Markers can be named and each has the Lat-Lon position automatically recorded in the marker window. This feature has been extremely helpful in returning to targets quickly for additional scanning or for a diving related inspection.
Creating a Mosaic of Scans
The ability to create a scan mosaic of the bottom is a very important feature when conducting a professional geophysical survey of an area. There are associated tools that provide adjustments that allow the scans to line up consistently with each other. The Layback feature is one of these tools that will provide a correction to the actual position of the scan based on the distance from the GPS antenna to that of the towfish.
Exporting Scan Files and Images
A single scan image in the png format or a complete scan XTF file can be exported very easily with just a click of a button.
Summary
DeepVision has created a side scan sonar system that provides both excellent high resolution imagery and range capability with all the features that meet the needs of the professional geophysical surveyor but at a cost that the shipwreck enthusiast can also afford. I have been operating side scan sonar systems for over 35 years and it is my opinion that the DeepVision DE340 is the best valued side scan sonar system on the market today. For additional details visit the DeepVision website:
www.deepvision.se