01 August (Angola ) within release Portuguese Empire goes into circulation Stamp Henry the Navigator (1394-1460) face value 1.75 Angolan angolar
Stamp Henry the Navigator (1394-1460) in catalogues | |
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Michel: | Mi:AO 279 |
Stamp is vertical format.
Also in the issue Portuguese Empire:
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Stamp Henry the Navigator (1394-1460) in digits | |
Country: | Angola |
Date: | 1938-08-01 |
Size: | 27 x 36 |
Perforation: | comb 13½ x 13 |
Format: | Stamp |
Face Value: | 1.75 Angolan angolar |
Stamp Henry the Navigator (1394-1460) it reflects the thematic directions:
Exploration is the process of exploring, an activity which has some expectation of discovery. Organised exploration is largely a human activity, but exploratory activity is common to most organisms capable of directed locomotion and the ability to learn, and has been described in, amongst others, social insects foraging behaviour, where feedback from returning individuals affects the activity of other members of the group
A navigator is the person on board a ship or aircraft responsible for its navigation. The navigator's primary responsibility is to be aware of ship or aircraft position at all times. Responsibilities include planning the journey, advising the ship's captain or aircraft commander of estimated timing to destinations while en route, and ensuring hazards are avoided. The navigator is in charge of maintaining the aircraft or ship's nautical charts, nautical publications, and navigational equipment, and they generally have responsibility for meteorological equipment and communications. With the advent of satellite navigation, the effort required to accurately determine one's position has decreased by orders of magnitude, so the entire field has experienced a revolutionary transition since the 1990s with traditional navigation tasks, like performing celestial navigation, being used less frequently. Using multiple independent position fix methods without solely relying on electronic systems subject to failure helps the navigator detect errors. Professional mariners are still proficient in traditional piloting and celestial navigation.