kepler
Oct22-04, 12:27 PM
Good afternoon,
I have some formulas to calculate ( aprox in most cases ) the diference between UTC ( CT ) and TDB. There are periods that already have a full coverage from the astronomers ( like the period 1600/1620 to ~2000 ).
Still, two problems remain:
1) The calculation of a specific time span: dates prior to 928 CE - the formulas that exist have accuracy until ~392 BCE ( if I'm not mistaken ). The nightmare is for the period from 700 BCE to 948 CE...
2) Extrapolation of delta T from 2000 to the far future ( let's say 10000 CE ) - JPL Horizons sticks with ~64 secondes ( they don't take chances or is just an error in the results) - all you have to do is in the output specifications choose the «delta T» option.
Does anyone have any ideas regarding this two points?
Regards,
Kepler
I have some formulas to calculate ( aprox in most cases ) the diference between UTC ( CT ) and TDB. There are periods that already have a full coverage from the astronomers ( like the period 1600/1620 to ~2000 ).
Still, two problems remain:
1) The calculation of a specific time span: dates prior to 928 CE - the formulas that exist have accuracy until ~392 BCE ( if I'm not mistaken ). The nightmare is for the period from 700 BCE to 948 CE...
2) Extrapolation of delta T from 2000 to the far future ( let's say 10000 CE ) - JPL Horizons sticks with ~64 secondes ( they don't take chances or is just an error in the results) - all you have to do is in the output specifications choose the «delta T» option.
Does anyone have any ideas regarding this two points?
Regards,
Kepler