{
  "$type": "site.standard.document",
  "description": "The system has a receiving unit whose rotatable interference filter (51) extracts electromagnetic radiation in defined wavelength range. A changing unit changes optical thickness such that extractable wavelength range is varied. The thickness is defined by refractive index of a cavity enclosed by…",
  "path": "/patents/993365",
  "publishedAt": "2013-01-30T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "G01B11/002",
    "HEXAGON TECHNOLOGY CT GMBH [CH]"
  ],
  "textContent": "The system has a receiving unit whose rotatable interference filter (51) extracts electromagnetic radiation in defined wavelength range. A changing unit changes optical thickness such that extractable wavelength range is varied. The thickness is defined by refractive index of a cavity enclosed by semi-reflecting mirror elements of the filter and distance between the elements. The changing unit comprises actuator to change positions of the elements and/or refractive index adjusting element to change the refractive index. The thickness is sequentially changed during operation. An independent claim is also included for a measuring method for determining coordinates of points for distance measuring, using a geodetic surveying device, a coordinate measuring machine or a scanning device.",
  "title": "Optical measurement system with filter unit for extracting electromagnetic radiation"
}