Re: [LEAPSECS] FW: comments on DRR TF.460-6

2010-09-28 Thread Poul-Henning Kamp
In message <91772dec8a29c048a9bfbe32c49ceb72e86...@echo.usno.navy.mil>, "Matsak is, Demetrios" writes: >I asked an unquestioned expert on celestial navigation about its UT >requirements. This was his response: >If you want >accurate longitude, you can't get around the need to know UT1 at no >wors

[LEAPSECS] FW: comments on DRR TF.460-6

2010-09-28 Thread Matsakis, Demetrios
I asked an unquestioned expert on celestial navigation about its UT requirements. This was his response: For observed stars that are near the celestial equator or at low declinations, the error can be up to 0.25 nm per uncorrected second. This is a systematic error, i.e., all lines of position f