Solar Raster Photography

We present pictures of my brother's back yard. They are panoramas that spans from due south in the middle to northeast on the left and northwest on the right.

Panoramic images made by the moving sun. post

Mostly you see trees and sky. That's a fir tree on the right and a palm tree beyond that.

My brother, Peter Cunningham, made these images on a computer from data collected over a year. That makes them time exposures for sure.

The moving sun illuminated the scene as it slowly progressed across the sky casting everything before it in silhouette. Passing clouds caused the static visible in parts of the open sky.

My brother added the white dots at intervals of ten degrees of azimuth and elevation.

The two picture were taken six months apart. You will notice the trees were a little thinner and the weather a little more variable in the first picture. Peter has three and a half years of data. That's enough for seven images.

Peter collects weather data, including solar irradiance, from a sensor array mounted on a post in his yard. He uses timestamps recorded with the data to synchronize its display with the calculable position of the sun in a process similar to the raster scanning of a television image. The stream of data from the sensor is in essence a slow-scan video signal, only the scan lines aren't straight and there is no camera at the source.

Let me say this once again.

These pictures were taken without the aid of cameras or lenses. That may be obvious from the discussion above. Still, most observers find the fact startling. I encourage you to ponder their production, which relies on the motion of the earth, the properties of light, and the endurance of computers. Enjoy.


See my own Webcam Sky Survey with similar data but without the projection.