ultramarin marine translations
nl azimutspiegel   navigatie-instrument dat bestaat uit een ring van niet-magnetisch metaal, en voor het maken van peilingen op het kompas wordt gezet;
de Kompaßdiopter
Navigationsinstrument, das aus einem Ring aus nicht-magnetischem Metall besteht, der zur Peilung auf das Kompaßgehaeuse aufgesetzt wird;
en azimuth mirror
azimuth circle
a navigational instrument consisting of a ring made of non-magnetic metal which fits over the top of a compass bowl and is used at sea for taking bearings of terrestrial or celestial objects.

miroir azimutal
alidade à miroir

es espejo azimutal
alidada azimutal
it cerchio azimutale apparecchio per rilevamenti disposto e rotante sul mortaio di una bussola; è munito di un prisma che consente le letture dei rilevamenti direttamente sulla rosa dei venti.
source: Thomas Gunn Navigation Services
  the azimuth mirror carries two sighting vanes for taking bearings of terrestiral objects. One of these vanes has a peep-sight and the other, immediately opposite to it, has a vertical sighting wire mounted in an open frame.
The observer turns the instrument around its vertical axis until the object comes on the extension of the line from the observer's eye through the peep-sight to the sighting wire. At the bottom of the wire frame is a reflecting prism so installed that it reflects the view of the compass card directly below the wire to the vision of the observer, enabling him to read the compass bearing while keeping the object lined up with the sighting vanes.
For bearings of the sun, use is made of two vanes at right angles to the sighting vanes. One of these vanes consists of a tilting mirror which can be adjusted to reflect the rays of the sun to a slit in the vane housing diametrically opposite. This housing contains a 45 prism which turns the ray of sunlight downward on the edge of the compass card. (International Maritime Dictionary)