Visibility of Luna and Lunar Crescent

Abstract
The pmbl.m of delemining ftc day when Uc nev tunar crcs.nl can be 3en ti6t
ar an, site of observarion hs Efrained an opch pobtem since andquirr, The
phenon.non ImniB imFnel for beeioing ! luw mon$ in a puEly ob*rvariomt
lunar calcnd.i. In li. n6! chapler the asrrcnomicat pdamercn relare.i lolheprobtcnr are
!.!ieRtd alohe si$ a briefdcsriplion oasme rules oafitrnb arribut.d ro rhc ancicnr
and lhe nr!ie!.1 nodets lhc afecrs ot geognphical loc.rion on rhc problcr orc aho
dcscribed. A brief Evierv ofc.tendaB lnd.ssociared celestiat cycles h atso pescnled
$nh splri.l chphasis on |hc rulcs enurcjarot for Islamic ob*rarionat lu.arcalcnd,r a
.{rlr as lo'r cemu, AD. ln lhe end of the ch.prf Eviov or rhe conlrib[ion of thc
.strcnoncrs of 2orr' cenrurr is pesentcd $al b.8im rvirh thc etoFical toodct or
Solvins fte pnblm ol lhe ti6l visibilny oa lbe n.$. lumr crcsccnr inlolvcs
lenedy colcrlations and thc trsc ofatt ctcFenrary !slrononjic0t rechniqucs. A tovi.w ot
n e tcchniq,es and algorilhms is pEsc .d in rhc *cond chlpr. Sp$i.l emphNis is
Ailrn lo r|r dekminarion oa linr of oriunclion of Moon sirh rhe SuD. i c binh of nc*
Moon. rh. risinsand seu'hgol thr Smnnd rhe M@n_ posnionsofrhc sun,nd thc Moor
ar 2n! tnrc on rhc dll or rc day aftc. conjL .rion .t.tc ch.prr cnds rith a brict
dsscrption of the .ompurer prosranr Hitotot dsvebp.d r'.r compftrioN done ir rhis
\ort A n$v posam is deEloped in ordq lo prcdnce the dala Fquied aor rhis \ol[
$ar is Cencrally.or avlitabte troh orher sotlwarc lhat aheadycxrsr
ShniDg $ilh simtl€ Ulbytonian crncrion. fic lhnd chaprr eiptores rhe ancienr
dnd the Drdielal hlrbeoaricat hodets follo\€d b, rhe dcscriprion ol. narh.natical
trploEion of oedieval Mutim Aslomn6. Condricat considehions asiaGd
wilh the prcblen are.xplorcd in nrore dclaitin oder ro evalu0le the Lunlr Ripencss Las
o.0 sMcess, suggc$ed in lhc medieval e6. 'ls
Son nodincado.s to rh€ la$ aru ate
suggesled Thc shoncominss of the ripenc$ lav a,c then di*ussd and lieht is shcd oD
rhe Easns rhat lead ro lhe dcvelopnent of ARCV-DAZ ,.trrion b4d nodels b, the