Hello Owend,


for Matt is important, what type of shapes is it in Your project possible: donut polygons or stacked area polygons, polylines, points?

I'm also interest for shape import in RM with selectable attribute. If this shape would be to edit in the user map, there is no limitation for charts in Lowrance and Garmin units (Simrad i don't know). But note, the own-chart options in Lowrance units are at the current time much better as in Garmin units.
For Garmin units look here: www.anglingcharts.com/tutorials/reefmastergarmin.html


Best wishes
fjordfisher

Hi Owen,

That's a nice dataset, but much too large an area for ReefMaster - it covers some 3M square kilometres, with 100m contours. ReefMaster is for creating high definition maps over much smaller areas, up to about 15km square.

Having said that, you should still be able to get that map data onto your Simrad (NSS or NSE?) but you would not use ReefMaster to do it. Instead you need to use a GIS application such as QGIS (free) to process the shapefiles and then run them through the free Navico Insight Map Creator tool. It looks like there is also grid data and some GeoTif image files, so you ought to be able to create a map with a coloured depth background raster and the 100m contours on top. It would be a big map, and not particularly high-definition, so I don't know how useful it would be for your needs. Of course, you could then use ReefMaster to create higher definition maps over smaller sections of this basemap.

If you want to give it a go, reply to this thread and I'm sure a few of us could talk you through the required processes.

Matt

Yes Matt,

vector chart from polylines - no problem with Lowrance units, more effort for Garmin units
vector chart from donut polygons - no problem with Lowrance units, more effort for Garmin units
vector chart from area polygons - problem, bad way for Garmin units, not so good for Lowrance units because LAYER restriction

raster chart from geotiff's - i believe not for Garmin units possible, with high resolution and not in deepest zoom levels (>= 2 ... 4 m/pix) possible for Lowrance units for such big areas (SD-card size limited).

Best wishes
fjordfisher

Just for fun, I have downloaded the data and opened it in QGIS. Nearly 400,000 contours (line objects) and an 18k square ESRI grid, over an area about 1250km square. I don't know if this could all go into a single AT5 map (Greg?) but you might be able to grab the bits that interest you..



If you wanted to try it, the process might be something like:

• Tidy up the contours - perhaps remove everything above land level (there are a lot of those).
• Add the contour attributes required for the IMC - the LIMIT values at the very least.
• Colourise the raster layer however you want it and export it - you probably need to run the resulting file through a conversion utility to get a KML or PGW calibration file for the IMC.
• Maybe try and get a polygon shapefile for the landmass that you can mask the raster with.
• Run the whole lot through the IMC...

Nice data set though!

Matt,


the file size is for vector AT5 not a problem. Yesterday i processed all germany topo OSM together (357.121 km²) with the following result:





Realistic and fast to realize for Owend is: land as yellow colored areas, water area as white or blue color + only lines with depth levels.


Best wishes
fjordfisher

Cool - should work then, although it might taker a while. The raster might be quite big, the raw grid is over a gig..

No performance problems in the unit!


But a raster-test with my federal land (23.200 km²) - result: the 1 m/pix AT5 files in summary are much bigger than a 64 GB SD-Card!!!

The raw raster is about 18k square, and the area is about 1200km square - so only 1 pixel per 60m or so. The problem (I think?) is that the raster would disappear at higher zoom levels if you just created it at the real pixel resolution, and the file would be too big to be created at higher zoom levels..

Here's the data in QGIS, with a polygon for the state of Queensland overlaid to mask the raster (found on an Aus govt website). Looks quite nice, with the raster colourised to white below 300m. Still not convinced this would be much use as a map though, just not high enough resolution.

I agree, it's not particularly great data.

They've been running multibeam sounders through that area since 1992 and doing tracklines in that area since 1960. It looks like the Kilo Moana has about 180 million multibeam depth soundings in that area from 2004 to 2007 that you might be able to generate a decent map from.

I'm taking a look at a few of those.

Wow,
Thanks for all the replies.
Sounds like a pretty major job to get anything useable.
I was hoping there would be more detail than what is in the currently available charts.

It's probably better than most charts out there but that's not saying a whole lot since the best data out there for the vast majority of that location is ETOPO. The chart is kind of worthless inside of 100 meters but will be decent for showing dramatic drop offs. It also looks fairly accurate (given the low resolution) compared to the different data sources I've seen.

In this case, any interpolation you do on this chart won't add a lot to the chart and will be extremely inaccurate around the reef. It's probably best to do a direct conversion with the IMC or recalculate the data with their source data for this project.