It is the basis for Coordinated Universal Time ( UTC ), which is used for civil timekeeping all over the Earth's surface, and for Terrestrial Time, which is used for astronomical calculations.

Difficulties were recognized, which led to these being in turn superseded in the 1990s by time scales Terrestrial Time ( TT ), Geocentric Coordinate Time GCT ( TCG ) and Barycentric Coordinate Time BCT ( TCB ).

The time scale represented by T < sub > eph </ sub > has been characterized as a relativistic coordinate time that differs from Terrestrial Time only by small periodic terms with an amplitude not exceeding 2 milliseconds of time: it is linearly related to, but distinct ( by an offset and constant rate which is of the order of 0. 5 sec / yr ) from the TCB time scale adopted in 1991 as a standard by the IAU.

Terrestrial salamanders catch their prey by rapidly extending a sticky tongue which adheres to the prey, allowing it to be pulled into the mouth.

In this role, TT continues Terrestrial Dynamical Time ( TDT ), which in turn succeeded ephemeris time ( ET ).

* the Uu interface, UMTS air interface, which links the User Equipment to UMTS Terrestrial Radio Access Network in a UMTS network.

UMTS specifies a complete network system which uses, covering the radio access network ( UMTS Terrestrial Radio Access Network, or UTRAN ), the core network ( Mobile Application Part, or MAP ) and the authentication of users via SIM cards ( Subscriber Identity Module ).

UMTS also specifies the Universal Terrestrial Radio Access Network ( UTRAN ), which is composed of multiple base stations, possibly using different terrestrial air interface standards and frequency bands.

( If its begin and end are defined using mean solar time ( the legal time scale ) then its duration was 31622401. 141 seconds of Terrestrial Time ( or Ephemeris Time ), which is slightly shorter than 1908 ).

* Terrestrial Time ( TT ) is the time scale which had formerly been called Terrestrial Dynamical Time.

As UT is slightly irregular in its rate, astronomers introduced Ephemeris Time, which has since been replaced by Terrestrial Time ( TT ).

Terrestrial planets have a solid planetary surface, making them substantially different from the much larger gas giants, which are composed mostly of some combination of hydrogen, helium, and water existing in various physical states.

Terrestrial planets possess secondary atmospheres — atmospheres generated through internal volcanism or comet impacts, as opposed to the gas giants, which possess primary atmospheres — atmospheres captured directly from the original solar nebula.

Freeview +, originally entitled " Freeview Playback ", is a consumer brand for the specification of Digital Terrestrial Recorders which is published and maintained by the Digital TV Group.

On 24 October 2012 Ireland's Analogue Terrestrial signal will be switched off and will be replaced by Saorview which was officially launched on 27 May 2011.

Mobile Terrestrial Television is TV on mobile phone handsets, which does not have contention problems compared to 3G networks.

It again carried the DFI package, as well as the OSTA-l payload – named for the NASA Office of Space and Terrestrial Applications – which consisted of a number of remote-sensing instruments mounted on a Spacelab pallet in the payload bay.

Scientists at NASA's Navigator Program, which specializes in the detection of terrestrial planets, have backed the launch of a Terrestrial Planet Finder ( TPF ) mission.

Most standard coordinates in use today refer to 2000 Jan 1. 5 TT ( i. e. to 12h on the Terrestrial Time scale on 2000 Jan 1 ), which occurred about 64 seconds sooner than noon UT1 on the same date ( see ΔT ).

Terrestrial microwave relay, a technology later introduced to link stations, has been largely supplanted by coaxial cable, fiber, and satellite, which usually offer superior cost-benefit ratios.

Terrestrial television is a mode of television broadcasting which does not involve satellite transmission or cables — typically using radio waves through transmitting and receiving antennas or television antenna aerials.

Upsilon Andromedae A was ranked 21st in the list of top 100 target stars for the NASA Terrestrial Planet Finder mission, which has, however, been reported to have been cancelled as of 2011.

In this regard, P25 fills the same role as the European Terrestrial Trunked Radio ( TETRA ) protocol, although not interoperable with it.

The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface.

Terrestrial Time ( TT ) is a modern astronomical time standard defined by the International Astronomical Union, primarily for time-measurements of astronomical observations made from the surface of the Earth.

For applications at the Earth's surface, ET's official replacement was Terrestrial Dynamical Time ( TDT ), since redefined as Terrestrial Time ( TT ).

Terrestrial Time is time at Earth's surface.

Terrestrial Palpigradi have hydrophobic cuticles, but littoral ( beach-dwelling ) species are able to pass through the water surface easily.

TDB is now ( since 2006 ) defined as a linear scaling of Barycentric Coordinate Time ( TCB ), and a feature that distinguishes TDB from TCB is that TDB, when observed from the Earth's surface, has a difference from Terrestrial Time ( TT ) that is about as small as can be practically arranged with consistent definition: the differences are mainly periodic, and overall will remain at less than 2 milliseconds for several millennia.

The International Terrestrial Reference System ( ITRS ) describes procedures for creating reference frames suitable for use with measurements on or near the Earth's surface.

Terrestrial species sometimes produce a few photosynthetic leaf-shoots which lie unobtrusively flat against the surface of their soil, but in all species only the flowering stems rise above and are prominent.

Terrestrial stationary waves is a persistent spherical conductor “ single-wire ” surface wave electrical transmission line phenomenon arising across the Earth's surface by virtue of the highly conductive nature of the earth itself.

Thus for clocks on or near the geoid, T < sub > eph </ sub > ( within 2 milliseconds ), but not so closely TCB, can be used as approximations to Terrestrial Time, and via the standard ephemerides T < sub > eph </ sub > is in widespread use.

For practical purposes the length of the ephemeris second can be taken as equal to the length of the second of Barycentric Dynamical Time ( TDB ) or Terrestrial Time ( TT ) or its predecessor TDT.

Cosmic rays can have energies of over 10 < sup > 20 </ sup > eV, far higher than the 10 < sup > 12 </ sup > to 10 < sup > 13 </ sup > eV that Terrestrial particle accelerators can produce.

Terrestrial planets can have canyons, craters, mountains, and volcanoes.

Terrestrial animals that can only produce ammonia would have to drink constantly, making a life on land impossible ( a few exceptions exist, as some terrestrial woodlice can excrete their nitrogenous waste as ammonia gas ).

It can also be rationalised as making the average length of the Martian week close to the average length of the Terrestrial week, although it must be remembered that 28 Earth days is roughly equal to 27 + 1 / 4 Martian sols and not 27 + 5 / 6 Martian sols.

Terrestrial soils of this nature need to adjust from fresh to saline interstitial water by a change in the chemistry and the structure of the soil, accompanied with fresh deposition of estuarine sediment, before salt marsh vegetation can establish.

The Exalted of Creation can be divided into two categories: Terrestrial Exalted and Celestial Exalted.

Celestial Exalted, being the chosen of the Celestial Incarnae, are significantly more powerful than Terrestrial Exalted, and can live for millennia, but their numbers are limited by a fixed number of Exaltations passing from mortal life to mortal life at any given time.

While less powerful, Terrestrial Exalted, or Dragon-Blooded, can pass on their Exaltation to their children, much like one would pass on other genetic features.

Elementals can be summoned through Terrestrial Circle Sorcery, however, unlike demons, powerful elementals often have designated proxies who can be sent to respond to the summoning in their stead.

TDB is a successor of Ephemeris Time ( ET ), in that ET can be seen ( within the limits of the lesser accuracy and precision achievable in its time ) to be an approximation to TDB as well as to Terrestrial Time ( TT ) ( see Ephemeris time-Implementations ).

Interactive TV can also be delivered via a terrestrial aerial ( Digital Terrestrial TV such as ' Freeview ' in the UK ).

Terrestrial cell antennas and networks can be damaged by natural disasters.

Lattelecom Terrestrial TV enables digital over-the-air broadcasting of TV signals that can be received using an indoor or external aerial.

PDTV sources can be captured by a variety of digital TV tuner cards from a digital feed such as ClearQAM unencrypted cable, Digital Terrestrial Television, Digital Video Broadcast or other satellite sources.

The multimedia element is able to read HDTV IPTV streams and includes a Terrestrial Numerical Television demodulator, can serve as a home A / V broadcasting station, includes a 40Gb hard drive for recording and time-shifting, and a load of A / V ports.

) After these factors have been taken into account, deviations between the observed arrival times and predictions made using these parameters can be found and attributed to one of three possibilities: intrinsic variations in the spin period of the pulsar, errors in the realization of Terrestrial Time against which arrival times were measured, or the presence of background gravitational waves.

Terrestrial microwave vehicles can usually be identified by their masts which can be extended up to 50 feet ( 15 m ) in the air ( to allow line-of-sight with the station's receiver antennas ), while satellite trucks normally use a dish that points skywards towards one of the geostationary communications satellites.