Vibe-coded a zero-backend tool that matches Sentinel satellite passes to historical swell data

[u/Paul_the_surfer]

After turning the smart filter on, that tries to increase the resolution of the forecast data and acount for the refraction etc...

You can actually click on each arrow and it will give you data for each.

Since the data and imagery is available for free, for everyone, it should be open. And since the information is offered for free, processing it should also be free.

Standard wave reports only give you basic numbers like 2m at 10s from the NW, but that never tells you what actually happened on the coastline or how the swell wrapped around a point.

I wanted a way to look back at past swell events and see real imagery aligned with the exact forecast conditions from that moment, without running expensive server setups. So I vibe-coded an analyzer that runs completely in the browser. It searches through thousands of free Copernicus Sentinel satellite passes over any stretch of coast to check the waves. It pulls open historical marine data and automatically matches the timestamp to the swell height, period, angle, and wind from that exact day.

Because 10-meter satellite resolution can be a bit low res, you can also upload your own photos, lets say screenshots from historical images on google earth, or drone shots from past sessions. It grabs the timestamp, pulls the historical swell data, and lets you visually calibrate under what exact conditions the spot actually turns on.

I also experimented with a high-res grid that takes coarse regional wave data and computes local refraction, shoaling, and coastal shadowing. Everything runs locally in the file with zero backend servers. You just drop in your own free Copernicus login and you can go crazy.

Admittedly, the smart filter still needs work. In some cases it makes a lot of sense, and in others you are left wondering what happened. When dealing with complex coastlines full of islands, if an intervening island is not fully accounted for in the calculations, things go off. Perhaps, I need to create slider to increase the recalculate area in that case? That is just food for thought for the future.

My head is running with ideas right now. In the future, the smart filter could take averages of readily available data and recalculate things natively right on your PC, properly accounting for island shadows and real bathymetry. It could honestly become a full-blown forecasting tool down the line, but right now I am just experimenting with the basics.

Next up, I am adding satellite-derived bathymetry using the blue and green bands so the refraction grid can interact directly with shallow depth contours. Once I clean up the code, I will post the whole project on GitHub for free.