Visually selecting charts to download

[Slovak]

Long time user, very much enjoying the many features of OpenCPN and the continuous improvements.

Perhaps I'm missing something obvious regarding chart downloads. I want to download charts for SE Alaska. I add the NOAA ENC Product Catalog for AK, update it, and now on the "Download Charts..." tab I'm faced with 481 charts from which to choose. Since I'm not familiar with the area, how do I know which of the 481 charts to download? I prefer not to load charts of areas I don't need, for performance and searchability reasons.

I went to https://charts.noaa.gov/InteractiveCatalog/nrnc.shtml and I see there's a multitude of charts available for SE Alaska. What's the best practice for getting charts for a specific subset of a geographical area? Is there a visual selector tool where I can highlight an area and based on the loaded catalogs it will pre-select recommended downloads?

[wholybee]

There is no such tool in OpenCPN. I loaded up OpenCPN with the entire NOAA catalog, and unless you are on a very old, very slow computer, loading all of Alaska shouldn't be a performance issue.

If you really only want a small area, you would need to use the NOAA tool to find the charts you need.

[Slovak]

Originally Posted by wholybee

If you really only want a small area, you would need to use the NOAA tool to find the charts you need.

The challenge with that approach is that OpenCPN descriptions of those 481 charts aren't super helpful. There are 12 instances of "Alaska" each with its own checkbox, and the names don't correspond to the actual chart designation, such as "US5AK3FM". Even though the official designations are used to store the charts in the directory structure, they don't seem to be referenced (with a pop-up perhaps) in the GUI.

[nohal]

Originally Posted by Slovak

The challenge with that approach is that OpenCPN descriptions of those 481 charts aren't super helpful. There are 12 instances of "Alaska" each with its own checkbox, and the names don't correspond to the actual chart designation, such as "US5AK3FM". Even though the official designations are used to store the charts in the directory structure, they don't seem to be referenced (with pop-up perhaps) in the GUI.

The data for the NOAA charts catalogs come directly from NOAA, nothing to do with OpenCPN.
There is no geo metadata available for anything but the NOAA charts, so building a visual selection tool is very low on priorities list, as it would not work anywhere but in the US.

[Slovak]

Originally Posted by nohal

The data for the NOAA charts catalogs come directly from NOAA, nothing to do with OpenCPN.

The AK_ENCProdCat.xml file being used (I assume) to populate the list of the available charts does contain the formal chart designation.

<name>US1AK90M</name>
<lname>Arctic Coast</lname>

The former could be used as mouse over help in the "Download Charts..." dialog instead of being dropped. The latter is more user friendly descriptive name to those who are familiar with the area.

Originally Posted by nohal

There is no geo metadata available for anything but the NOAA charts, so building a visual selection tool is very low on priorities list, as it would not work anywhere but in the US.

Understood. Alaska being 2/3 of land mass of the continental US and having more coastal miles than the rest of the US is an outlier. Though, because of its remoteness I'm looking at options to slim it down instead of downloading / updating all 481 charts each time.

[requiem]

Originally Posted by Slovak

<name>US1AK90M</name>
<lname>Arctic Coast</lname>

The former could be used as mouse over help in the "Download Charts..." dialog instead of being dropped. The latter is more user friendly descriptive name to those who are familiar with the area.

I'd suggest prepending rather than doing it as a tool-tip; good UX typically calls for a brief delay before a tooltip appears (e.g. 250 ms), but at least for me such delay would be interminable.

If it's possible to edit a config file and "pre-check" the desired charts, ChartWorld's online shopping interfaces allows geographical selection. Once the desired charts are selected, copy the names (may need a bit of script-** to strip out the key values) and merge them into said config file.

[Slovak]

Originally Posted by requiem

I'd suggest prepending rather than doing it as a tool-tip; good UX typically calls for a brief delay before a tooltip appears (e.g. 250 ms), but at least for me such delay would be interminable.

I'm a fan of seeing more info, I was just suggesting some kind of use of the information already in the xml.

Originally Posted by requiem

If it's possible to edit a config file and "pre-check" the desired charts, ChartWorld's online shopping interfaces allows geographical selection. Once the desired charts are selected, copy the names (may need a bit of script-** to strip out the key values) and merge them into said config file.

Now we're in business! Thank you!

I went to https://www.chartworld.com/shop/off_...hart-selection and selected with the rectangle the area of interest. It lists the selected maps by code. Extract the list from HTML, clean up with some sed-** to arrive at a clean list of desired maps, one per line.

Next step - modify the xml file to include only the cleaned up list of desired maps. Reload the xml in OpenCPN, "Select All", download.

Replace xml with original version. Update catalog so that the original version is reflected, now I only have the desired maps of the 481 as selected.