Modes
See also: Aviation transponder interrogation modesMode 1 – provides 2-digit 5-bit mission code. (military only – cockpit selectable)
Mode 2 – provides 4-digit octal unit code. (military only – set on ground for fighters, can be changed in flight by transport aircraft)
Mode 3/A – provides a 4-digit octal identification code for the aircraft, assigned by the air traffic controller. (military and civilian)
Mode 4 – provides a 3-pulse reply to crypto coded challenge. (military only)
Mode 5 – provides a cryptographically secured version of Mode S and ADS-B GPS position. (military only) Mode 5 is divided into two levels. Both are crypto-secure with Enhanced encryption, Spread Spectrum Modulation, and Time of Day Authentication. Level 1 is similar to Mode 4 information but enhanced with an Aircraft Unique PIN. Level 2 is the same as Mode 5 level one but includes additional information such as Aircraft Position and Other Attributes.
Mode C – provides 4-digit octal code for aircraft's pressure altitude. (military and civilian)
Mode S – provides multiple information formats to a selective interrogation. Typically aircraft are assigned a unique 24-bit Mode S address. The Mode S address is partitioned and a group of address ranges are allocated to each country. Some countries change the assigned address for security reasons, and thus it might not be a unique address. (military and civilian)
- Notes
Modes 4 and 5 are designated for use by US ARMY, USAF, USN, and NATO forces.
Read more about this topic: Identification Friend Or Foe
Famous quotes containing the word modes:
“The history of reform is always identical; it is the comparison of the idea with the fact. Our modes of living are not agreeable to our imagination. We suspect they are unworthy. We arraign our daily employments.”
—Ralph Waldo Emerson (1803–1882)
“The human condition is such that pain and effort are not just symptoms which can be removed without changing life itself; they are the modes in which life itself, together with the necessity to which it is bound, makes itself felt. For mortals, the “easy life of the gods” would be a lifeless life.”
—Hannah Arendt (1906–1975)
“Without any extraordinary effort of genius, I have discovered that nature was the same three thousand years ago as at present; that men were but men then as well as now; that modes and customs vary often, but that human nature is always the same. And I can no more suppose, that men were better, braver, or wiser, fifteen hundred or three thousand years ago, than I can suppose that the animals or vegetables were better than they are now.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)