Detection device for detecting the intensity of a light signal emitted by a light source, said light source generating a light signal modulated at a first frequency (f 0) or at a second frequency (f 1), said device comprising: - a standalone energy generator comprising a photovoltaic module supplying a charging current (Icharge), - electrical energy storage means powered by the charging current (Icharge) supplied by the standalone energy generator, - processing means, - a reactivation circuit for the processing means of the detection device, the reactivation circuit comprising: - a circuit for eliminating false reactivations, connected at the output of the generator, said false reactivations being due to a single variation of the intensity of the signal or to a modification of a duty cycle of the light signal, the circuit comprising a rectifier circuit designed to detect a maximum amplitude of the charging current (Icharge), - detecting means for detecting the signal modulated at a second frequency (f 1), different from the first frequency, connected to the output of the circuit for eliminating false reactivations, said detection means comprising a resonant circuit, - tripping means for tripping a reactivation of the detection device when the signal is modulated at said second frequency (f 1), comprising a comparator with two inputs, the first input of the comparator being connected to the rectifier circuit to receive a voltage equal to the sum of the voltage measured at the terminals of the resonant circuit and of the voltage measured at the terminals of the rectifier circuit and the second input of the comparator being connected to a reference voltage representative of the voltage at the terminals of the electrical energy storage means, characterized in that the generator is the receiver of the first frequency and of the second frequency. - a standalone energy generator comprising a photovoltaic module supplying a charging current (Icharge), - electrical energy storage means powered by the charging current (Icharge) supplied by the standalone energy generator, - processing means, - a reactivation circuit for the processing means of the detection device, the reactivation circuit comprising: - a circuit for eliminating false reactivations, connected at the output of the generator, said false reactivations being due to a single variation of the intensity of the signal or to a modification of a duty cycle of the light signal, the circuit comprising a rectifier circuit designed to detect a maximum amplitude of the charging current (Icharge), - detecting means for detecting the signal modulated at a second frequency (f 1), different from the first frequency, connected to the output of the circuit for eliminating false reactivations, said detection means comprising a resonant circuit, - tripping means for tripping a reactivation of the detection device when the signal is modulated at said second frequency (f 1), comprising a comparator with two inputs, the first input of the comparator being connected to the rectifier circuit to receive a voltage equal to the sum of the voltage measured at the terminals of the resonant circuit and of the voltage measured at the terminals of the rectifier circuit and the second input of the comparator being connected to a reference voltage representative of the voltage at the terminals of the electrical energy storage means, - a circuit for eliminating false reactivations, connected at the output of the generator, said false reactivations being due to a single variation of the intensity of the signal or to a modification of a duty cycle of the light signal, the circuit comprising a rectifier circuit designed to detect a maximum amplitude of the charging current (Icharge), - detecting means for detecting the signal modulated at a second frequency (f 1), different from the first frequency, connected to the output of the circuit for eliminating false reactivations, said detection means comprising a resonant circuit, - tripping means for tripping a reactivation of the detection device when the signal is modulated at said second frequency (f 1), comprising a comparator with two inputs, the first input of the comparator being connected to the rectifier circuit to receive a voltage equal to the sum of the voltage measured at the terminals of the resonant circuit and of the voltage measured at the terminals of the rectifier circuit and the second input of the comparator being connected to a reference voltage representative of the voltage at the terminals of the electrical energy storage means,