I Listen and repeat the pronunciation of the words. Find the sentences with. The words in the text. In small groups, discuss the meanings of the words

The words in the text. In small groups, discuss the meanings of the words

And give the Kazakh or Russian equivalents.

1 mapping radars

2 unmanned aircraft

3 map-matchers

4 distinctive terrain

5 missiles measure

6 patches of terrain

7 the long-term drift

8 a baro-inertial altimeter

9 inertial navigator

10 optical mappers

II scan the text to match the clauses together to make sentences.

А

1 On aircraft, mapping radars and optical sensors present

2 Automatic map-matchers have been built since the 1960s

3 Since 1980, aircraft and cruise missiles measure

4 Updating with the matched profile, perhaps hourly, reduces

5 The profile of the terrain is measured

B

a by subtracting the readings of a baro-inertial altimeter (calibrated for altitude above sea level) and a radio altimeter (measuring terrain clearance).

b the long-term drift of the inertial navigator.

c the vertical profile of distinctive patches of terrain below the aircraft and match it to a stored profile.

d that correlate the observed image to stored images of patches of distinctive terrain, choosing the closest match to update the dead-reckoned state vector.

e an image of the terrain to the crew, whereas on unmanned aircraft, navigation must be autonomous.