| 摘要 |
<p>A semi-active laser (SAL) seeker system is disclosed. Radiation 8 emitted by a laser designator 2 is incident on a target 10, which reflects the light. The emitted radiation is polarised by a series of optical components which may comprise a polarizer 4 and a quarter wave plate 6. Circular polarisation may advantageously be used as it is rare in nature and does not constrain the rotational orientation of the designator or the seeker. Specular reflection of circularly polarised light changes the handedness of the polarisation. The invention relies on ensuring that the light 12 reflected from target 10 has a strong known polarisation. The seeker includes optical components which may comprise a quarter wave plate 14 and a polarizer 16 acting so that the detector 18 receives light of a given polarisation. The use of polarised light improves the signal to noise ratio by 3dB and allows the range to the target 10 to be increased by approximately 41%. A simple PIN diode detector may be used.</p> |
