Signature Terre, 1989.

Sixteen squares of black plastic fabric with sides measuring 60m were used to create the «Planet Earth» symbol that covers an area of 390,000 square metres (780 x 500m).
The installation was performed with the help of thirty people who manoeuvred 10-m-wide plastic rollers along a path traced on the ground by surveyors. Great difficulty was encountered when the 10 x 60m strips of plastic caught the wind. They had been anchored at each end, but hundreds of used tyres had to be distributed over their surface to keep them flat on the ground. The symbol was precisely angled in relation to the north-south movement of the satellite so that the figure would appear to stand completely upright on the image obtained.
Source: spacearts.info

Art-Spot 'Signature Terre', 1989

Visible from space, "Signature Terre" is a gigantic ground installation that reaches its full significance with the satellite views presented.