Topic: Is Reefmaster using the SI data too?

[gcornelisse]

What I've been able to do with Reefmaster so far is very cool.  I'm excited to export the contours back to my 798 and get back on the lake.  However, the software seems to only use the depth pings directly under the boat?  I had my SI setup to scan 100ft on either side of the boat, but that doesn't seem to be represented in the maps Reefmaster creates.  Is there something I have to do or can do to utilize all the additional data?  I think that extra data would really help to create more accurate maps for a wider area instead of me having to spend so much time cruising around.

Thanks,
Gary

[xSilmarilSx]

The SI data doesn't contain depth data, so it cannot be used to make maps in any programs.

In future version, Reefmaster should be able to superpose SI scan on the map.

[matt@reefmaster]

Hi Gary,
As Silmaril says, the SI log data does not contain extra depth information for areas to the side (at least, not in a way that is practical to extract). To be honest, although in theory you could generate higher definition maps more quickly if there were some way to gather depth information from the SI, in practive a 100-150 foot gap between tracks is not a large distance to interpolate, and you should get decent enough maps by running tracks at this distance (or even more). You can spend more time over areas of particular interest - or just leave the logging on whilst fishing them - to increase the detail.

The latest release of RM included the ability to import Google Earth KML overlay images. This means that you can import SI mosaics created with programs such as SonarTRX and overlay them on your 3D models, with on-the-fly adjustable transparency, any number of image layers etc. The results can look pretty cool:



cheers,
Matt

[gcornelisse]

The reason I ask is because when I view my recording in HumViewer, it can tell me the depth of any point within my SI range.  How do they do it?

I want to use the data for fishing, and the more detail I can get the better.  The lake I'm mapping is not available on any store bought nav chip.  Single lane road beds, old foundations, sunken ponds, small rock humps and creek beds are critical to catching fishing on the lake.  100-150 ft resolution is going to pass right over any hint of that kind of stuff.  Don't get me wrong, having any contours at all is simply awesome.  But, being able to see some of these moderately sized structures is even better.

[matt@reefmaster]

HI Gary,
I'm not sure Humviewer does show you that depth - although I could be wrong. I think that if you move your mouse horizontally within the SI image, the depth will stay the same - the depth is only changing as you move along the track (ie - there is a single depth for each SI ping).
The only way you will get the sort of bathymetric resolution you are after is to run closer tracks - although of course you only need to do this over areas of interest. If you mosiac your sidescan logs using SonarTRX, and then import and overlay them within RM, you shouldn't miss too much!

cheers,
Matt

[gcornelisse]

You're right!  HumViewer doesn't have the depth info.  That's disappointing.  I guess that means I just have to do more fishing so I can record more data!