Does anyone have information on a peculiar plotting system used by the Soviet PVO (Air Defense) forces during the Cold War? Perhaps it was adopted by the Warsaw Pact, as well. Reportedly, it was based on a 3 x 3 matrix, yielding 9 squares or blocks, numbered 1 through 9, in clockwise order, beginning with 1 at top left and ending with 9 as the center square. Each larger square was divided into a smaller 3 x 3 matrix, etc. This system was used to exchange information through the PVO chain of command.
Matrix numbering pattern:
Matrix numbering pattern:
| 1 | 2 | 3 |
| 8 | 9 | 4 |
| 7 | 6 | 5 |
