A temperature compensation circuit for a light source (e.g., light emitting diode (LED)) whose radiant energy output decreases when ambient temperature increases includes a first circuit element for generating a first current that increases proportional to an increase in the ambient temperature, and a second circuit element for generating a second current that is first order independent of the ambient temperature. The circuit further includes a weighted current adder for generating a third current by combining the first and second currents with first and second weights applied to the first and second currents respectively. The circuit further includes a third circuit element responsive to the third current for supplying a fourth current to the light source to maintain a radiant energy output of the light source constant independent of the ambient temperature.

Provided is a light source correction method for low-light detection, which relates to the technical field of remote detection. The light source correction method includes following steps: S1: determining whether brightness of a light source exceeds a predetermined value, and if the brightness of the light source exceeds the predetermined value, performing step S2; or if the brightness of the light source does not exceed the predetermined value, performing no operation; S2: driving a shielding plate located in front of a luminous flux detection board to rotate around a rotating shaft to obtain a luminous flux intensity on the luminous flux detection board; and S3: drawing a curve graph showing that the luminous flux intensity varies with a rotation position of the shielding plate, and calculating position information of the light source.