An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Number of Results: 3 Search : datum
datum
  ۱) داده؛ ۲) داده‌بن؛ ۳) فرازبن   
1) dâdé (#); 2) dâdebon; 3) farâzbon

Fr.: donnée   

1) A single piece of information, as a fact, statistic, or code.
2) Any numerical or geometric quantity which serves as a reference or a base for measurement of other quantities.
3) Surveying: Any basis level (surface, line, or point) used as a reference in measuring elevations.

L. datum "given," neuter p.p. of dare "to give, offer," cf. Av. and O.Pers. dā- "to give, grant, yield," Av. dadāiti "he gives," Skt. dadáti "he gives," Gk. didomi "I give," PIE base *do- "to give."

Dâdé "given," p.p. of dâdan "to give," Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," akin to L. data, as above.
Dâdebon, from dâdé "datum," + bon "basis, base," → element.
Farâzbon, from farâz "above, up, upon," → height, + bon "basis, base," as above.

geodetic datum
  داده‌بن ِ زمین‌سنجیک   
dâdebon-e zamin-sanjik

Fr.: donnée géodésique   

Any of the adopted values of → geodetic latitude, → geodetic longitude, or → azimuth at a selected location (an initial station) whose astronomical coordinates have already been determined.

geodetic; → datum.

Mars datum
  فرازبن ِ بهرام   
farâzbon-e Bahrâm

Fr.:   

The → zero point of elevation on Mars. It is the elevation at which the atmosphere pressure is 6.1 millibars, or 610 → Pascals. Atmosphere pressure has to be used because Mars has no ocean, and "sea level" cannot be used like on Earth. More formally, the datum is a fourth-order, fourth-degree surface of equal → gravitational potential (determined from the Viking orbiter spacecraft) such that the pressure of the atmosphere is 6.1 millibars (source: Lunar and Planetary Institute, USRA).

Mars; → datum.