CIVIL ENGINEERING DEPARTMENT
DIPLOMA GEOMATIK UKUR (DGU) ---------------------------------------------------------------------------------------------------------------------
DCG2063 FIELD ASTRONOMY ---------------------------------------------------------------------------------------------------------------------
REPORT: SOLAR OBSERVATION ---------------------------------------------------------------------------------------------------------------------
PREPARED PREPARED BY : HAMIDZIE BIN OTHMAN ID NO NO : 0!DGU!"F!022 CLASS : DGU2A
PREPARED FOR : PUAN SHARIFAH LAILATON KHADI#AH BINTI SYED ABDULLAH DATE OF SUBMISSION: 2$ MARCH 20!%
TABLE OF CONTENTS
B&'
C*+*,
1.
Title of Practical Work
2.
Introduction
3.
Purpose / Objectives
4.
Euip!ent "sed
#.
Procedure Works
$.
%esult &'ookin()
*.
+nal,sis / -ata o!putation
.
onclusions &o!!ent)
P.+
SOLAR OBSERVAT ION REPORT
INTRODUCTION +0i!ut deter!ination fro! solar observations as been around and practiced b, surve,ors and navi(ators for centuries. Wile so!e tecnolo(ies suc as P ave !ade a0i!ut deter!ination fro! observin( celestial bodies less co!!on oters suc as electronic teodolites 5it po5erful onboard co!puters and ti!in( devices ave !ade solar and stellar observations !ore convenient and accurate. +ltou( at tis ti!e no instru!ent !anufacturer as an onboard solar epe!eris and reduction pro(ra!s 5ereb, te observer 5ould point to a reference !ark and te un/star and read te a0i!ut of te line instantl, te tecnolo(, o5ever is ere no5 to acieve tis. In te last $ or * ,ears te use of astrono!ical observations in surve,in( as seen a (reat co!e back. Once a co!!on tool in land surve,in( te (ro5t of urban surve,in( over te ,ears since te 16478s see!ed to ave caused a decline in te use of astrono!, for a0i!ut deter!inations. In 164 PO' 9a(a0ine publised an article entitled :+dvanta(es of te ;our +n(le 9etod for un Observations8 b, -avid %.
fro! tat it is used to deter!ine te true bearin( before startin( te adastral urve,. It is necessar, to ceck previous bearin(s in te ertified Plan. True 'earin(s are used 5en 5e 5ant to re>fi= te da!a(ed or lost boundar, stones.
PURPOSE / OBJECTIVE Te purpose or objective of tis practical activit, are? a)
To e=pose students on o5 to co!pute an observation 5eater based on te star or sun in (ivin( te bearin( of te line 5ic refers to true nort.
b)
+ble to appl, te concept of solar observation in a true adastral urve, 5ork.
c)
To understand on o5 to read te observations properl, and accuratel,.
d)
To understand on o5 to book and co!pute te bookin( based on te step of te solar observation calculation (iven.
e)
To prepare student to (et use to te situation on te real 5ork.
f)
To understand on o5 read te @+l!anacA.
EQUIPMENT
Tripod &1 units) E-9 or Total tation &1unit) >to find te an(le and !easured te distance
>used as a platfor! for supportin( te 5ei(t and !aintainin( te stabilit, of te total station or te pris!
un Bilter &1 units)
>to protect te e,es fro! ultraviolet radiation &"C) and blue li(t 5ic can cause several serious e,e proble! 5en observin( te sun
FIELD WORK PROCEDURE
F&./+ !
F&./+ !1
F&./+ !
F&./+ !
Te field 5ork involved in te deter!ination of a0i!ut of a line fro! sun observation consists of follo5in( steps? 1. arr, out te!porar, adjust!ent of a teodolite at te observation station 5it face left condition. 2. Open te lo5er plate !ain scre5 and s5in( te telescope to bisect te reference object. Bi= te lo5er plate !ain scre5 and bisect accuratel, usin( te lo5er plate tan(ent scre5. Dote do5n te ori0ontal circle readin(. 3. 5in( te telescope b, openin( te upper plate !ain scre5. 'rin( te i!a(e of te sun into te upper left uadrant of te diapra(! &Bi(ure 1a). lose te upper plate !ain scre5 and ten brin( te vertical air tan(ent to ri(t li!b of te sun usin( te upper plate tan(ent scre5. +s soon as te lo5er li!b of te sun !akes contact 5it te ori0ontal air te crono!eter ti!e is recorded. Dote do5n te ori0ontal &as 5ell as vertical if altitude of te sun is reuired to be observed) circle readin(s.
4. De=t brin( te i!a(e of te sun into lo5er ri(t uadrant usin( te upper and vertical plate tan(ent scre5s. Te vertical air is kept in tan(ent to left li!b of te sun usin( b, te upper plate tan(ent scre5. +s soon as te upper li!b of te sun !akes contact 5it te ori0ontal air te crono!eter ti!e is recorded &Bi(ure 1b). Dote do5n te ori0ontal &as 5ell as vertical if altitude of te sun is reuired to be observed) circle readin(s. #. Open te upper plate !ain scre5 and s5in( back te telescope to te reference object. lose te upper plate !ain scre5 and bisect te reference object. Dote do5n te ori0ontal circle readin(. $. an(e te face left of te instru!ent into te face ri(t condition and repeat step 2 5it te instru!ent in face ri(t condition. *. 5in( te telescope b, openin( te upper plate !ain scre5. 'rin( te i!a(e of te sun into te upper ri(t uadrant of te diapra(! &Bi(ure 1c). lose te upper plate !ain scre5 and ten brin( te vertical air tan(ent to left li!b of te sun usin( te upper plate tan(ent scre5. +s soon as te lo5er li!b of te sun !akes contact 5it te ori0ontal air te crono!eter ti!e is recorded. Dote do5n te ori0ontal &as 5ell as vertical if altitude of te sun is reuired to be observed) circle readin(s. . De=t brin( te i!a(e of te sun into lo5er left uadrant usin( te upper and vertical plate tan(ent scre5s. Te vertical air is kept in tan(ent to ri(t li!b of te sun usin( te upper plate tan(ent scre5. +s soon as te upper li!b of te sun !akes contact 5it te ori0ontal air te crono!eter ti!e is recorded &Bi(ure 1d). Dote do5n te ori0ontal &as 5ell as vertical if altitude of te sun is reuired to be observed) circle readin(s. 6. %epeat step #. Tus a set of observation is to be taken. It consists of four instants of ti!e and four ori0ontal circle readin(s &and four vertical circle readin(s). +n a0i!ut of te line +F sould be co!puted for eac pointin( on te sun. Bor an, field observation it !a, consist of one or !ore sets but a !ini!u! of tree sets is reco!!ended.
RESULT (BOOKING)
ANALYSIS / DATA COMPUTATION A COMPUTATION OF THE SOLAR OBSERVATION 1. +s soon as te solar observation ave been booked a calculation of te solar observation in findin( an a0i!ut !ust be co!pute ri(t a5a,. 2. Birstl, te avera(e solar an(le 5as calculated as belo5 ? +vera(e ori0ontal solar an(le H
Total ori0ontal an(le 4
3. Te result is ten filled in +vera(e ori0ontal solar an(le ro5. 4. De=t step 2 5as repeated te sa!e 5a, in findin( te avera(e altitude. 'efore tat for te vertical an(le of te left face 67 7 > G and for te an(le on te ri(t face G > 2*7 7. Ten fro! tere te avera(e vertical an(le can be find b, usin( te step as belo5 as +vera(e vertical solar an(le H
Total vertical an(le 4
#. Ten fro! tere to find te altitude step belo5 5as used orrected altitude H +vera(e vertical solar an(le > paralla= and r efraction Te paralla= and refraction &biasan dan bedaliat) are based on te reverse &back) of te solar observation Bor!. $. De=t to find te %O ori0ontal avera(e an(le step belo5 5as used %O ori0ontal avera(e an(le H
Total %O ori0ontal an(le 2
*. Ten te coordinate for te observation station 5as been done b, usin( te step belo5. Ori(inal oordinate D/ and E/W H (iven accordin( location of te tate Observation tation oordinates D/ and E/W H obtained fro! te respective observation tation Fatitude H Ori(inal Fatitude > -ifference = 7.7732 Ori(inal Fatitude H (iven accordin( location of te tate
. Ten to find te a0i!ut of te sun b, usin( te step as belo5 -eclination H refer to te tar +l!anac #* -ifference H 7 1$! = 7 2#! = 3$77
#* 3$77
Polar -istance P H 67 7 J -eclination &soutern sun) or 67 7 > -eclination &nortern sun) alculated +0i!ut sun b, usin( te for!ula belo5 osine +0i!ut H
cos P >&sin K = sin L) cos K = cos L
6. Not last but least, after the azimuth of the sun, the nd the dierence
step below was used. -ifference H+0i!ut of sun > Te +vera(e to te sun 17. Next, from the dierence, we can nd by following the step below. Trut %O H -ifference J %O ori0ontal avera(e an(le %O rid bearin( H Trut %O ± te !isclose &tirusan)
11. Lastly, to nd the average R !rid "earing step below was used %O rid bearin( H
deviation 1 J deviation 2 2
&Dotes >
please
refer
respective surve, class)
to
te
B OBSERVATION RULE 1.
Observation can be carried out eiter in te !ornin(s or afternoon. Te vertical an(le observed !ust be bet5een 1# > 37 e=ceptions to certain cases. Eac solar observation reuires 2 set observation and eac sets consists 4 observations of te sun.
2.
Te reference !ark &%O) is taken fro! te back bearin(. %eadin(s are taken 5en te ori0ontal are cuts te sun trou( central point and te vertical a=is coincides 5it tan(ent of te sun.
3.
-ata of declination an(le is referred to te tar +l!anac for surve,or. Bor second class surve,s te a0i!ut value bet5een t5o sets of observations !ust not e=ceed 37 seconds and for first class surve, !ust not e=ceed 17 seconds.
4.
'ased on te solar observations bearin(s are calculated and recorded in te solar observation for!.
CONCLUSION / COMMENT Birst of all i 5ould like to tank our astrono!, lecturer Pn iti
To e=pose students on o5 to co!pute an observation 5eater based on te star or sun in (ivin( te bearin( of te line 5ic refers to true nort.
2.
+ble to appl, te concept of solar observation in a true adastral urve, 5ork.
3.
To understand on o5 to read te observations properl, and accuratel,.
4.
To understand on o5 to book and co!pute te bookin( based on te step of te solar observation calculation (iven.
#.
To prepare student to (et use to te situation on te real 5ork.
$.
To understand on o5 read te @+l!anacA.
Trou(out conductin( te observation te proble!s tat been face durin( te solar observation is tat observation cannot be carried out perfectl, due to bad 5eater suc as cloud, rain, or even a0e. 'eside tat te factor in findin( te a0i!ut value bet5een t5o sets of observations !ust not e=ceed te li!its is due to te incorrect readin( of te teodolite or E-9 or even incorrect in centerin( te bubble of te euip!ent. Bro! tis activit, i can sa, tat teres are uite a lot observation tat been !ake trou(out tis se!ester. 'et5een all te observed result i !ana(ed to co!pute 2 closed observation 5it te li!it does not e=ceed 17A and even 2 closed observations 5it te li!it e=ceed 1M. +s for te rest of te observations i !ana(ed to co!pute a second class surve,.