Automatic identification of STATE of the GROUND SOLIA SOLIA sensor determines the state of the ground, indicates the occurrence of freezing precipitations and measures the height of snow. It can be used in synoptic (SYNOP) and aeronautical applications (automatic METAR) or road (alarms). SOLIA consists of a light source and two receivers installed at approximately at one meter above the ground. The axis of the receivers is located in the same vertical plan and is cut in the center of the reference area (target) enlightened by the transmitter. One of the receivers is sensitive to the light returned by spectacular reflection by the target; the other receives the diffused retro light. The measurement of two luminous flows allows discriminating various surface qualities of the horizontal black flagstone placed at the ground. The temporal analysis of the signals allows detecting precipitations. The accurate measurement of the temperature of the target allows to distinguish certain states from solid water which have the same optical signature than other states of liquid water. The modular concept (transmitting and receiving heads separated, independent protected box), the local user interface and the easy to use and sure ergonomics of the IHM allow a fast installation and a simple use of the equipment. The self calibration (compensation of the ageing and moisture of the target) and the monitoring of the operating conditions (status) allow to reduce the number of intervention on the sensor, which does not require any special equipment for its fitting. The configuration of the parameters, the remote control and the software updates can be also carried out remotely, via the connection RS232 and/or integrated modem FSK.

Functionality Acquisition : • Every 0.5 seconds, luminous energies emitted, reflected and retrodiffused by the target are measured using silicon photodiodes and an analogical/digital converter 12 bits, through an analogical chain self calibrated with 3 gains and automatic selection. Precise measurement of the temperature by platinium probe (PT100Ω 4 wires). Measurement validation following elements : • Lamp voltage, supply voltages, flow wiring, emitted light flux, abnormal dust contamination of the optics and the target, validity of the parameters and the software, temperature of the optical...