The NWS runs several weather radars, as is their overall purvue, and one of the services they offer is an over the top 'enhanced' version. Which is great and all. Until you need just a quick glance at what's happening. They also offer a 'standard', or low-res, version that's a series of gif images that can be looped to get a quick feel of what the weather is doing.
The only issue is that these images are transient and only shows the current radar images.
This program will continuously download the radar images and save them to a local directory. In order to not be a bad net citizen, this program honors the cache-control max age response to determine when it should attempt to get the next available image. Some random jitter is also added so we can avoid possible traffic retrieving the same image at the exact same time.
In the configuration, it requires a radar station to be provided. There's not a good listing of available stations so the following are provided for ease of use. Other stations can be interactively discovered at https://radar.weather.gov/
CONUS- Entire continential United States aggregate imageKIWA- ArizonaKCBX- Western IdahoKSFX- Eastern IdahoKMAX- Southern Oregon
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Configuration:Fork: The source version of the NWS Looper -
Configuration:Email: A required point of contact email that the NWS requires; will be sent in plaintext with every request to the NWS. Per https://weather-gov.github.io/api/general-faqs -
Settings:BasePath: The location where to save the retrieved images -
Settings:DatePattern: To keep the filenames unique and sortable, the current timestamp is leveraged. This is the format applied to the date so it's compact and scriptable -
Settings:NwsRestApiUrl: The base URL for the National Weather Service REST API -
Settings:Station: The NWS Station Id for the radar images; e.g. KIWA, KCBX, etc -
Storage: Details of where to store the downloaded Radar images and such -
Archive:BasePath: The path where the archives will be saved, needs to be readable/writable by the program. The system will check that it exists and the permissions are correct. -
Archive:FilePattern: This is the format applied to the date so it's compact and scriptable -
Archive:ArchiveDelay: The number of hours a file needs to exist before it's available for archiving. e.g. If the value is set to 18, only files older than 18 hours will be considered for archiving. This is based off of the last time the file was modified.
- Validate that the
User-Agentlogic works as expected.
- Deal with duplicate radar images
- Deal with missing radar images
- Figure out how to generate AOT binaries - that way we just have a single executable instead of a directory
- The images should be saved in a directory structure of something like
<basepath>/<station>/timestamp.gifso that multiple instance can be run concurrently without issue. - Create animated gifs from the prior set of images for displaying loops
- https://www.nuget.org/packages/Aspose.Imaging/
- https://github.com/dlemstra/Magick.NET/blob/main/docs/CombiningImages.md
- https://github.com/dlemstra/Magick.NET/blob/main/docs/ResizeImage.md
- https://github.com/dlemstra/Magick.NET/blob/main/docs/Readme.md
- https://github.com/dlemstra/Magick.NET/blob/main/docs/CrossPlatform.md
- https://github.com/dlemstra/Magick.NET
- https://kb.aspose.com/imaging/net/how-to-create-gif-from-images-in-csharp/
- https://learn.microsoft.com/en-us/dotnet/architecture/microservices/multi-container-microservice-net-applications/background-tasks-with-ihostedservice
- Create a systemd file to run this as a service on linux
- keep this running if it dies.
- https://devblogs.microsoft.com/dotnet/net-core-and-systemd/
- Validate that the email for the User-Agent has been provided. Nothing fancy at first, just that there's a value.
- Save headers to json for later processing - zip file entries can have a huge comment. Take the json file and insert it as a comment to the zip file. Determine json format for the comment as well.
- When a new image is retrieved, it should a) be copied to a "current" image; b) trigger the animated gif logic so that a new loop is generated.
- On start, verify requested directories are writable.
- Exit cleanly with an understandable error message if the directory isn't writable
- Provide a list of stations instead of just a single station so that a single instance can be leveraged.
This project does create and delete files. While care has been taken to prevent unintended damage, there are no guarantees. Take care with the settings and verify them before executing.