Wednesday, December 3, 2008

Where is the Sun?

I've had this in mind for quite a while..., I wanted to mix Google Map and some celestial navigation algorithms to know where the Sun is, and specially to avoid the time when the Sun is right in the direction where I'm driving on the 101, as that makes every car to stop.
Based on Jean Meeus' Astronomical Algorithms, and the great work done by Henning Umland, here is a first drop, available here.
You enter your date (top right panel), and you click on the map.
From the point you've clicked, you should see on the map the direction of the Sun.

Monday, December 1, 2008

New 3D rendering for the GRIBs

We can now have a better 3D rendering for the GRIB data.
The thing is to be able to stack whatever data is available in the GRIB on top of another one, along with the chart.
The check boxes at the bottom of the panel do the job, they're activated when the data they describe are available. Stacking waves and Pressure at Mean Sea Level for example, unsurprisingly shows that the waves are bigger where the pressure is low.
To manipulate this kind of image, just imagine it is in a glass ball. And then rotate it just like if you where using a track ball... The mouse moves the image just like your hand or thumb at the surface of the ball.