Changeset 1688

Timestamp:

Sep 3, 2004, 11:02:24 AM (22 years ago)

Author:

Paul Price

Message:

Clarified behaviour for UT1-UTC for dates outside the range of the
tables.

File:

• trunk/doc/pslib/psLibADD.tex (modified) (3 diffs)

trunk/doc/pslib/psLibADD.tex

@@ -1 @@
-%%% $Id: psLibADD.tex,v 1.35 2004-09-01 22:23:44 price Exp $
+%%% $Id: psLibADD.tex,v 1.36 2004-09-03 21:02:24 price Exp $
 \documentclass[panstarrs]{panstarrs}
 
@@ -52 +52 @@
 Hipparcos and Tycho Catalogues      & \code{http://astro.estec.esa.nl/Hipparcos/CATALOGUE_VOL1/catalog_vol1.html} \\
 Zombeck                             & ``Handbook of Space Astronomy and Astrophysics'', second edition, \code{http://ads.harvard.edu/books/hsaa/toc.html} \\
+Reingold \& Dershowitz              & ``Calendrical Calculations: The Millenium Edition'', Cambridge University Press, 2002. \\
 \hline
 \DocumentsEnd
@@ -909 +910 @@
 \code{http://hpiers.obspm.fr/eoppc/eop/eopc01/eopc01.1900-2004}
 
-Dates outside the ranges of the above tables shall generate an error.
+Dates outside the ranges of the above tables shall generate a warning.
+Dates later than those covered by the table shall be extrapolated
+using the formula contained in the Bulletin A
+(\code{ftp://maia.usno.navy.mil/ser7/finals.all}); the formula shall
+be easily configurable without recompiling (as the formula may change
+with each Bulletin A).  Dates prior to the those covered by the table
+shall simply assume that TDT is identical to UTC (which, from Reingold
+\& Dershowitz Figure 12.2 appears accurate to $\sim 10$ sec to about
+1700).  Archeoastronomy is not a perceived PSLib application, so there
+is no need for high precision at such early dates.
 
 These tables shall be read in only when required by the user, and