Thanks to Scott at NSW Wrecks for the great data! (1m gridded multi-beam)

What was the file format used for this?

Dan

Hi Dan,
The data I received was in a CSV file with UTM positions and negative depths, which took a bit of pre-processing to get into a format suitable for RM (LAT, LON WGS84, +Depth in metres). I believe the orignal data was gathered using a multi-beam sonar.

I have some data from in ersi grid and xyz asci format for an area about 30km long and with an average width of 5km. A similar 1m/pixel resolution multibeam survey to UKHO data. Depths are all positive but the x and y components appear to be a grid reference of sorts.

I have been able to get the ersi grid file in to qgis and it is bathymetric porn. But I am not sure what the process to getting the data into RM would be.

Any help would be greatly appreciated as it would take a life time to gain this much data on the water.

Dan

Dan,

There's a good chance that the coordinates are in UTM. RM doesn't work with those directly, but there are various to do it. We are giving the CSV import an overhaul in the next release that will include a choice of projections, column ordering, +ve/-ve depth etc (and maybe data thinning as well). In the mean time, if you share a link to your file to our contact address I could probably convert your file for you - which area is it for?

Bear in mind that 30 x 5km @ 1m would be in the order of 150m data points. That's way too much for RM to handle in one go, as we are really geared towards high resolution maps of small areas. We can handle about 4M points per map, at a push (still would still be a huge amount to actually collect, with a single-beam sonar). If your data was thinning, to say a 4m grid, then you should be able to map it quite easily as 2/3 sections.

Matt

Matt,

I am uploading the data now but it will take a while. I will email you the link once it is there. Thank you for the help.

Dan