It seems there are 22 squares with various symbols on them. The 21st Aug solar eclipse happens to be the 22nd in Saros cycle 145. The symbols might be referring to the previous eclipses in this cycle (the last was the total eclipse in England, 11th Aug 1999). The last square has a circle with a short line attached. This resembles the 21st June crop circle in West Kennett and hence a reference to this year? After that the next symbol is no longer inside a square and possibly referring to the continuation of this Saros cycle in the future.

The first three symbols (attached to the circle) seem to be simply numbers 1, 2 and 3 (one full square, two dots,three squares). Also the following symbols might be numerical symbols of an unknown language? As for the radio mast symbology... Is it a coincidence that the Chilbolton code formation (an apparent response to the Arecibo radio message) appeared on 21st Aug 2001 - exactly 16 years ago from the solar eclipse this year? Especially since number 16 is present in the three previous formations (12 petals and four corners in Hannington, two 8-pointed star in Little Compton and 16 spokes in Wootton Wawen).

The three little dots inside the main ring shape are maybe a countdown to 21st Aug (after the date of appearing it is 18th, 19th and 20th Aug) similarly as the 13 dots of Wootton Wawen formation (13 days between it's appearance and the 21st).