Global elevation tiles in PMTiles and on IPFS

[hfu]

In preparing #359, it would be great to have an open global elevation tiles (in PMTiles package).

Do you have any idea in implementing this? Digital Twin should be on a good topography.

@ubukawa Do we already have one?

[hfu]

I found this great entry by @ubukawa:
https://qiita.com/T-ubu/items/a90c3d42f809725f50ab

[hfu]

Can we use Mapzen Terrain Tiles (under Linux Foundation and AWS Market Place)?

https://aws.amazon.com/marketplace/pp/prodview-x7vtai3hasf26?sr=0-1&ref_=beagle&applicationId=AWSMPContessa#usage

Maybe we can just follow this by @shi-works:
https://qiita.com/shi-works/items/2d712456ccc91320cd1d#maplibre-gl-js%E3%81%A8awsmapzen-terrain-tiles%E3%81%A73d%E5%9C%B0%E5%BD%A2%E3%82%92%E8%A1%A8%E7%A4%BA%E3%81%99%E3%82%8B

[hfu]

I prioritized this because I am working on Smart Local (#426).

[hfu]

@ubukawa kindly introduced the following two entries on how o create global elevation tiles from NASADEM:

• large scale: https://qiita.com/T-ubu/items/c7bb5697b51f245ef163
• small scale: https://qiita.com/T-ubu/items/ced8423e0ebeda8c9244

[hfu]

Porting of @ubukawa's global elevation tiles

@ubukawa kindly offered access to the global eleation tiles from his backup data. @hfu will be downloading these packages for hosting using IPFS in future.

File list (for downloading by @hfu)

The files will be deleted onice @hfu has downloaded the files. So, these URLs are not for public use.

small scale (up to z=6, sourced from Global Map data)

• https://www.unvt-test.com/elevation/0-0-0.mbtiles

large scale (sourced from NASADEM)

• https://www.unvt-test.com/elevation/6-53-21.mbtiles
• https://www.unvt-test.com/elevation/6-53-22.mbtiles
• https://www.unvt-test.com/elevation/6-53-23.mbtiles
• https://www.unvt-test.com/elevation/6-53-24.mbtiles
• https://www.unvt-test.com/elevation/6-53-25.mbtiles
• https://www.unvt-test.com/elevation/6-54-23.mbtiles
• https://www.unvt-test.com/elevation/6-54-24.mbtiles
• https://www.unvt-test.com/elevation/6-54-25.mbtiles
• https://www.unvt-test.com/elevation/6-56-21.mbtiles
• https://www.unvt-test.com/elevation/6-56-22.mbtiles
• https://www.unvt-test.com/elevation/6-56-23.mbtiles
• https://www.unvt-test.com/elevation/6-56-24.mbtiles
• https://www.unvt-test.com/elevation/6-56-25.mbtiles
• https://www.unvt-test.com/nasadem1.zip
• https://www.unvt-test.com/nasadem2.zip
• https://www.unvt-test.com/nasadem3.zip
• https://www.unvt-test.com/nasadem4.zip

Additional information

These elevation tiles are produced using scripts in https://github.com/ubukawa/nasadem-rgbify.

[hfu]

Site repo

I created a GitHub repository for a test site.

https://github.com/optgeo/gel

[hfu]

Test site screenshot

[hfu]

ズームレベル高いものの合成ができるようになってきました。

合成のためのスクリプトは、次のようにしています。

require 'sqlite3'

system "rm merged.*"
system "cp 0-0-0.mbtiles merged.mbtiles"
$target = SQLite3::Database.new('merged.mbtiles')

def add(path)
  (z0, x0, y0) = File.basename(path, ".mbtiles").split('-').map{|v| v.to_i}
  source = SQLite3::Database.new(path)
  source.execute('SELECT * FROM tiles') {|r|
    (z, x, y) = r[0..2]
    y = 2 ** z - y - 1
    print "#{z} #{x} #{y} - > 6 #{x >> (z - 6)} #{y >> (z - 6)} - #{z0} #{x0} #{y0}\n"
    $target.execute(
      "INSERT INTO tiles (zoom_level, tile_column, tile_row, tile_data) VALUES (?, ?, ?, ?)", 
      r
    ) if (x >> (z - 6)) == x0 and (y >> (z - 6)) == y0
  }
end

Dir.glob("6-*.mbtiles") {|path| add(path)}
system "pmtiles convert merged.mbtiles merged.pmtiles"

[hfu]

西から回ってきて、アフリカの西岸まで辿り着いてきました。

[hfu]

Source Cooperative からの publishment について相談を開始してみました。

英語話者の方々にとって、@ubukawa のこのエントリが非常に役立つのだと思うに至りました。
https://qiita.com/T-ubu/items/c7bb5697b51f245ef163

[hfu]

This was successfully completed by #464!