Ground control point device and SAR displacement measuring system

A ground control point device installed at a control point of a synthetic aperture radar (SAR) displacement measuring system which performs an SAR analysis, the ground control point device comprising:

• an SAR wave reflector configured to receive an SAR wave incident from an SAR in an incident direction and to reflect the SAR wave in the incident direction;
• a global navigation satellite system (GNSS) receiver configured to receive a GNSS wave to generate, based on the GNSS wave, time information and positional information indicative of a position of the control point;
• an SAR wave receiver configured to receive the SAR wave;
• and
• a control point data generator/transmitter configured to generate control point data obtained by associating the positional information when the SAR receiver receives the SAR wave with a time instant of reception of the SAR wave that is determined based on the time information, and to transmit the control point data to outside.