chartmaker - Download FAA VFR and IFR digital raster charts and translate into mbtiles databases for other mapping applications

Requirements: Python 3, Node.js, Perl, pngquant, curl, and GDAL v3.6.2

Installation:

1.) This node.js application is designed to run on Linux, and also runs well on WSL2 (Windows Subsystem for Linux)
2.) Clone the repository, change directory to chartmaker, open a terminal and enter npm install
3.) Give execute permissions to perlsetup.sh shell script and run it to install perl dependencies
4.) Install the pngquant png image compression utility: (deb example) sudo apt install pngquant
5.) Run the application in a terminal with the command node make
6.) Go do something else... depending on the number of charts and image quality, the process can take several hours to complete.

chartdates.json

The FAA publishes charts 20 days before the official chart date, and chartmaker will automatically select the nearest chart date from this file of official FAA chart 56-day release dates, all the way up to the year 2044. If the next chart date is more than 20 days out, chartmaker will get the current chart date.

settings.json

• Edit the values in chartprocessindexes with any ordinal index numbers from the faachartnames list for charts you want to process, in the order you want them processed. The default is all charts in the index list, in index order. The setting array faachartnames are the actual zip filenames the FAA uses and are for reference only. Changes to the downloadtemplate or faachartnames, layertypes, and tiledrivers lists are not recommended!
• The zoom range value can either be in the format n-n, or you can use a single zoom level n
• You can change the tileimagequality percentage from 1 up to 100 and tiledriverindex index to 2 (webp) to reduce mbtiles file size. The smaller the percentage, the fuzzier the chart will be.
  • The tiledimagequality setting works for both png and webp images.
• To save disk space, you can set cleanprocessfolders to true.
  • The merge and/or pngquant work folders will be many gigabytes for the entire chart set and are not needed once processing is complete
• To preserve the processed databases, you can set renameworkarea to true. This will rename the workarea folder to include the processed chart date so the next run will not overwrite the folder.

settings values

• attribution is a database metadata value that many mapping applications use for acknowledgement of the database creator*

"attribution": "Aviation charts <a href='https://github.com/n129bz/chartmaker'>github.com/n129bz/chartmaker</a>"   

• wget download templates, values inside brackets <> are replaced with values to match FAA's file names*

"vfrdownloadtemplate": "https://aeronav.faa.gov/visual/<chartdate>/All_Files/<charttype>.zip"   
"ifrdownloadtemplate": "https://aeronav.faa.gov/enroute/<chartdate>/<charttype>.zip"

• application flags

"renameworkarea": false       <- if true, will append chart date to the working folder name  
"logtofile": true             <- if true will produce a file "debug.log"  
"cleanprocessfolders": false  <- if true then working folders are removed after processing

• tile image quality percentage, tileimagequality has a huge effect on png processing time, not quite as much with webp*

"tileimagequality" : 80   <- percentage (1-100) greatly affects processing speed and database size
"zoomrange" : "0-11"      <- range of overviews to produce, higher takes longer and can make db huge

• chartprocessindexes control which chart types to process, the array values correspond to their ordinal position in the faachartnames list, NOTE: any actual alias name should not contain any spaces*

"chartprocessindexes": [0,1,2,3,4,5], <- charts represented by indexes 0-5 will be processed, in this order   
"faachartnames": [   
    ["Grand_Canyon", "vfr", ""],      <- as in [FAA chart file name, type, no alias needed for vfr charts]   
    ["Helicopter", "vfr", ""],   
    ["Caribbean", "vfr", ""],   
    ["Terminal", "vfr", ""],   
    ["Sectional", "vfr", ""],   
    ["DDECUS", "ifr", "Enroute_Low"]  <- alias for the file DDECUS (which means Digital Data Enroute Continental US)   
]

• layertypeindex controls the layertype and therefore how it will be rendered on the map*

"layertypeindex": 1,   
"layertypes": [   
    "baselayer",    
    "overlay"   
]

• tiledriverindex determines the tiledriver type, for example webp produces the smallest image size but png produces the sharpest images*

"tiledriverindex": 2,   
"tiledrivers": [   
    "png",   
    "jpg",   
    "webp"   
]

Additional information

The chart zip files are downloaded from the FAA digital raster chart repository and unzipped. After the unzipping process all of the the resultant GEOtiff image names (and their matching tfw world file names) are "normalized" to all lower-case filenames with underscores in place of dashes and spaces and any apostrophes removed. This simplifies the down-stream processing of these files since GDAL can interpret spaces as argument separators.

ToDo:

Suggestions welcome!

inspired by https://github.com/jlmcgraw/aviationCharts