1. Prismatic compass

2. Scope: 1-Definition. 2-Description. 3-Types of prism. 4-Azimuth.
5-How does it work .
6-Applications.

3. Definition:
a hand compass equipped with sights and prisms to permit aiming the instrument at a point and at the same time reading the compass direction of the point due to its luminescent qualities, makes the device ideal for use in any environment where visibility is somewhat limited

4. Description: 1-Lid. 2-Two glass covers. 3-Magnetic compass card.
4-prism.

7. Prism:
In optics ,a prism is transparent optical element flat polished surfaces that refract light . The exact angle between the surfaces depend on the application.
A prism can be used to break light up into its constituent spectral colors .
Prisms can also be used to reflect or to split light into components with different polarization.
& it is used for measuring azimuth.

8. Types of prism:

9. 1-Dispersive prism :
dispersive prism are used to break up light into its constituent spectral colors because the refractive index depends on frequency.

10. 2-Grisms(grating prisms):
a reflection grating replicated onto a prism allow light to diffract inside the prism ;which increases the dispersion by the ratio of refractive index of the medium to the air .

11. 3-Polarizing prism :
it can split abeam of light into components of varying polarization .

12. 4-Reflective prism :
it’s used to reflect light for instance in prismatic sighting compass.

13. The azimuth:
Azimuth is defined as a horizontal angle measured clockwise from a north base line or from any fixed reference plane or easily established base direction line.

14. How does it work ?

15. 1. Select the bearing on which you want to march. 2
1. Select the bearing on which you want to march. 2. Open the lid and fold it flat. 3. Undo the knurled knob and move the bearing round to the top 4. Tighten the knurled knob 5. Line up the two illuminated sticks 6. Point the compass 7. Walk forward ensuring that the two illuminated sticks do not separate

17. Applications : It is used in many practical applications including:
1-Navigation
2-Astronomy
3-Mapping
4-Archayology
5-Minning

18. Liquid prismatic compass

21. The End