Sat2Chart

[Jon Hacking]

Originally Posted by Blueblue

Hi Miyalk,

I recently started using Sat2Chart and SasPlanet on a completely fresh install of Windows 10 Pro, and experienced slow downloads and crashes. The thing which solved it for me, after installing the latest version of Sat2Chart version 16.0.10.0, was deactivating Windows Defender Real-time protection. I could reproduce the issue, and got crashes after a while every time I had it on. Now I've added exclusions in Defender excluding everything which involves the chart making process.

//Martin

First, welcome to CF, Blue. We hope you find it useful.

And thank you for this post, as you're absolutely correct. I've had to turn off Defender's real-time protection when upgrading my old SAS cache from the file-system to SQLite. It hasn't been a problem (for me) when downloading SAS content, but it wouldn't surprise me if it got in the way of SAS downloads (for some folks) as well.

I've also found that I've had to tell Defender to ignore (exclude) scanning the ooRexx Program folder, as it didn't like some files in there.

[Wilyum]

are there any other online databases other than chartlocker where you can download and share mptiles?

[Jon Hacking]

Originally Posted by Wilyum

are there any other online databases other than chartlocker where you can download and share mptiles?

Hi Wilyum. As far as I know, there are currently 3 public repositories of downloadable mbTiles:

1. I think we have the biggest, in our Chart Downloads page. It covers the entire coastlines of over 30 countries, including all of the Eastern Caribbean, Galapagos, Micronesia, much of SE Asia, much of the tropical Indian Ocean, & even significant parts of East Africa, including Madagascar. Our charts include full satellite imagery from ArcGIS, Bing (MSFT) & Google, as well as nautical charts from CMap & Navionics. We include all zoom levels from Z10-18, which means individual coral heads are visible. And the accuracy is such that they're exactly where charted, with max errors on the order of 3m or 10'. Multiple zooms also improves the performance of OpenCPN, allowing it to simply extract the currently displayed zoom & slam it out to the display engine, rather than having to fiddle bits to determine which are to be displayed & which thrown away, which seems to be a bottleneck for OpenCPN's display engine. While this results in larger files, disk space is pretty cheap these days.
   
   
2. Sherry McCampbell, on Soggy Paws, publishes both her own charts, as well as those of Terry Sargent, of Valhalla fame, on the Satcharts page of her website. These are somewhat smaller than ours, which certainly saves disk-space, & they cover different areas. In general, they focus on places folks are likely to go, rather than the entire coastline of a country. Sherry also includes several downloadable track files on her page, which we also have, but we put ours on a separate Track-files page.
   
   
3. And as you note, there's Bruce Balan's Chart Locker, which is also a bit more conscious of file-size. Bruce has more content in the South Pacific & Japan than any of the others, since that's his current cruising ground.

I should point out that there's no real competition here. We've all been liveaboard cruisers for decades, & both of them are our good friends. We've all noticed the tremendous improvement in cruising efficacy & safety these charts offer, & we're all trying to improve that as best we can.

[Miyalk]

Thanks Martin, I have been out sailing, will check this when I get home.

[Stingo]

There's probably already a link to a YouTube video on how to use the Sat2Chart software, but a search didn't help.
Does anyone have a link to it or to the Phil Higgins YT channel, please?
TIA

EDIT: Found them, so please ignore this post.

[Stingo]

Originally Posted by Jon Hacking

Hi Wilyum. As far as I know, there are currently 3 public repositories of downloadable mbTiles:
....

Hi Jon, who do you use for hosting your collection of charts?

I ask because I now have a huge collection of mbtile charts that I've made and which it would be a pleasure to share with other cruisers, but when I created a download page on my website, and then uploaded nearly 500Gb of charts, the hosting company that I currently use got all stroppy about limited space, despite having an "unlimited" policy. I lost that argument when they threatened to close my account.

Btw, all my charts follow your excellent guidelines ie
Navionics Marine z10 - z18
Navionics Sonar z10 - z18
Cmap z10 - z18
Bing/GE/ArcGIS z17 - z18

[aqfishing]

Originally Posted by Stingo

There's probably already a link to a YouTube video on how to use the Sat2Chart software, but a search didn't help.
Does anyone have a link to it or to the Phil Higgins YT channel, please?
TIA

EDIT: Found them, so please ignore this post.

Please share!

[Stingo]

Originally Posted by aqfishing

Please share!

Here's a good start
https://youtu.be/ZmLm1A4INQI?si=rM2yUyKBqSd1Ny1i

[Stingo]

More here
https://youtube.com/playlist?list=PL...I2OyStGsndViSb

And here
https://youtu.be/kCDPn3KM918?si=vm_gB_smPM1paizR

And here
https://youtu.be/0FTrGbltByw?si=LLVsa-0E1I4ReGrK

[aqfishing]

Thanks so much.

[Stingo]

Originally Posted by aqfishing

Thanks so much.

My pleasure.
Jon Hacking's how-to page is also very, very indepth and informative and worth the time it'll take to read it from start to finish.
Making mbTiles

[Jon Hacking]

Thanks for the kudos, Stingo.

I use Mega in NZ. I bought 2TB for a one-time fee, & I can add to that as needed. They have an app for syncing to their cloud storage (& across devices) so I can backup our photos & other important docs there as well. They also do secure communications (chats) & other things. I used to use MediaFire, but they wanted fees every year. And yeah, my hosting outfit had a fit at my storage requirements as well. Pretty lame, given that disk space is so cheap these days.

Mega's big on security, so they encrypt everything, which I don't really need. This also requires that when someone clicks on a link to download something, it has to bring up another tab on their browser, so it can be decrypted. I don't need this, & I'd rather just have the file download right away, but it's a small price to pay.

Cool that you have such a large library, & that you're wanting to share it.

• What areas to you have?
• Would you like to collaborate?
  If so, send me a PM with your email & we can take this offline.

You say you have CMap, but CMap_4D & CMap_4D_Extra haven't been working for a while.

• Are they working for you?
• Or did you go with CMap Basic?

You say you have Bing/GE/ArcGIS, but only at Z17 - Z18.

• Was this a misprint, or did you actually leave out Z10-Z16 for the satellite imagery?
  If so, this could impact OpenCPN performance. Including them would only increase mbTile file size (& download times) by ~6%, as Z17 & Z18 will constitute 94% of the total file size.

I can also show you some tricks to glom your small mbTiles into larger ones, which will eliminate most of the piano-keys at the bottom of your OpenCPN display, making OpenCPN much easier to use.

[Stingo]

PM sent, Jon Hacking

[Wilyum]

Originally Posted by Jon Hacking

I can also show you some tricks to glom your small mbTiles into larger ones, which will eliminate most of the piano-keys at the bottom of your OpenCPN display, making OpenCPN much easier to use.

Im interested in this capability, is it a quick explanation? Or perhaps a linked tutorial?

[Jon Hacking]

Originally Posted by Wilyum

I'm interested in this capability [to glom small mbTiles into larger ones], is it a quick explanation? Or perhaps a linked tutorial?

Wilyum, What I do is:

1. Create a big route that encompasses the entire area that I’m interested in. This can be a fairly loose fit, & doesn’t have to be exact. It can also cover islands & atolls as well as the ocean between them. For example, the entire Easter Caribbean islands from Grenada to Puerto Rico, or half of the Maldives.
   .
2. Create high level (Z10-12) mbTiles of this area, in my standard map-types (ArcGIS, Bing, Google, CMap, & Navionics), so I know where the coast & any reefs or islands are.
   .
3. Use these in OpenCPN, separated into Chart Groups, to create my (smaller) routes around areas I’m interested in. These can be quite small, with multiple routes for each island, as needed.
   .
   BTW, I’m moving away from linear routes these days, in favor of closed polygons. SAS only works with closed polygons, so it’s easy for Sat2Chart to convert a closed polygon GPX into the type of file SAS uses. But linear routes are more difficult. Paul’s put a lot of work into improving his conversion algorithm, but it can still leave holes if I, for instance, zig-zag back & forth across a bay or small group of islands. A lot of my older routes did this, but now I just create a closed polygon for that area.
   .
4. Export & feed these routes to Sat2Chart, as normal, for all my maps. This will download the content into SAS’s cache, & create a bunch of mbTiles, but I actually throw the mbTiles away (let them accumulate in a temporary folder, & then delete that folder).
   .
5. In Sat2Chart, tell SAS NOT to download any content, since it already has everything it needs in its cache.
   .
6. Feed my original big route(s) to Sat2Chart again, Z10-18, for all 5 of my maps. This final step goes pretty quickly, as SAS doesn’t have to download any content. It just takes what it can from its own cache, the previously downloaded content, & builds the best mbTiles it can. This also means that if/when I’m doing a bunch of islands or atolls, it will pick up the high altitude zooms of the ocean between islands (what was downloaded in step #2), but not the detail (which would bloat the mbTile unnecessarily).

What I’m left with is a single mbTile that covers a lot of area, so I don’t have to click on piano keys all the time (don’t ever get old!). In cases of big countries like Indonesia or the Philippines, a create a network of large-area polygonal routes that share corner waypoints, so I can adjust those corner waypoints if necessary & still know I’ve covered the entire country.