เส้นเมริเดียนมีความสำคัญกับสิ่งใด

��ѵ��ʵ�� ʵ�� ؤ��Ӥѭ ��з�ջ

��鹰ҹ��ǡѺ��ʵ��š

�ѡɳ��ٻ�ç�ѳ�ҹ�ͧ�š��ѡɳС��Ẻ Speriod ��㹷ҧ��Ժѵ��Ҷ��š��ѡɳзç��ҧ�âҤ�Ե �ѧ��к��ԡѴ��ʵ��ͧ�š�֧��ǹ��Сͺ��仹��

��ǧ��˭� (Great Circle)
�� ͺǧ��ҡ��ҹ��ͺ��š�¼�ҹ��ٹ��ҧǧ�� Ǻ�è��ǧ�� ¡��"ǧ��˭�" ��ҧ �� ٹ��ٵ� ��¹��ç��ѹ ��ࢵ�״-��ҧ
��ǧ�� (Small Circle)
�� ͺǧ��ҡ��ҹ��ͺ��š��ҹ��ٹ��ҧǧ�� Ǻ�è��ǧ�� ҧ �� 鹢�ҹ
��ٹ��ٵ� (Equator)
�� 鹷��ҡ��ҹ�ٹ��ҧǧ��ǵ��ѹ�͡��е��ѹ�� ¨ش��鹢ͧ��鹷�� 0 ͧ�ҷҧ��ѹ�͡ ��ǧ��˭�ǧ˹��蹡ѹ
��¹ (Meridians)
�� 鹷��ҡ��ҹ�ٹ��ҧǧ��˹�� ҡ��ҧ�ش��š�˹�� Т��š��
��¹ �� (Prime Meridian)
��¹��ҡ��ҹ�ʹٴ�Ƿ��Ӻš�չԪ (Greenwich) ��ѧ�� ѡ㹡�á�˹��ͧ�Ԩٴ ��觶١��˹��ͧ�Ԩٴ��ٹ�� Ҷ�͵��͵�ŧ�ҹҪҵ� �.�. 1884 ��¡�� ¹��չԪ ��
��鹢�ҹ (Parallels)
�� 鹷��ҡ��ҹ�Ѻ��ٹ��ٵ� �� ǧ��
�еԨٴ (Latitude) ��
�� зҧ�ԧ��Ѵ价ҧ�˹��ͧ��ٹ��ٵ� �Ѻ�ҡ 0 ͧ��价ҧ�˹��зҧ�� 90 ͧ��
�ͧ�Ԩٴ (Longitude) �� ǧ
�� зҧ�ԧ��Ѵ�ҡ��¹��觶�ͷ�� 0 ͧ�� Ӻš�չԪ��ѡ �Ѵ价ҧ��ѹ�͡ 180 ͧ�ҵ��ѹ�͡ ��зҧ��ѹ�� 180 ͧ�ҵ��ѹ�� "��駵�ᤧ �ǧ��" �繤��¡�ҹ��µ�͡�è�� еԨٴ��ͧ�Ԩٴ�� ѡɳ��ҧ��
��çἹ��
�� к��ͧ��鹷��ҧ��㹾�鹷��ẹ�Һ ��ʴ��ѡɳТͧ��鹢�ҹ��¹�ѹ�繼ŨҡẺ��Ըա��ҧ�ٻ�ç�âҤ�Ե ��С��ҧ��Ե��ʵ��㹡�ö��·ʹ��ҹ�鹨ҡ��š ��繷ç��ŧ��鹷��ẹ�Һ ��Ըա�ù�� ¡��ҡ�é��Ἱ�� ¡��鹼��ٻ�ç�âҤ�Ե 3 ��Դ �� ٻ�йҺ (Plane) �ٻ�ç�� (Cone) ��ٻ�ç��к͡ (Cylinder) 㹡�é��çἹ��

��ਤ��蹢ͧἹ��
�� к��¹��鹷��᷹��¹��鹢�ҹ (Meridians and Parallels) �ͧ�� ǹ��ǹ˹��ŧ��ẹ�Һ��ҵ��ǹ
��˹�ͨ�ԧ (True North)
��Ƿ��Ѻ�ҡ�Ӻ�� ѧ��š�˹�ͨ�� Longitude �ء�� Ƿ��˹�ͨ�ԧ ��ѭ�ѡɹ��ٻ��᷹��˹�ͨ�ԧ �·��⻨��˹�ͨ�ԧ㹡��ҹἹ��
��˹�͡�Դ (Ἱ��) (Grid North)
��鹡�Դ��-�˹�ͺ�Ἱ�� ѭ�ѡɳ� GN ��˹�͡�Դ��ª��㹡��Ҥ�ҾԡѴ��༹��Ҥ�ͧ��
��˹�� ( Magnetic North)
��ǵ��١�÷��ʴ��˹�ͧ͢��. ��»��ȨЪ��价ҧ��˹�ͧ͢��š�� Ἱ��ѭ�ѡɳ��ٻ�١�ä��觫ա ��˹��硨��ª��㹡��ҷ�ȷҧ��Ի��Ȩ�ԧ
�Ы��ط ( Azimuth)
��Ըա�÷��Դ��㹡�ú͡��ȷҧ ��Ѵ��Ҵ�ͧ��ҧ�Һ��Ѵ�ҡ�Ƿ��˹��ѡ��¹��ԡ��Һ�è��Ѻ��·��ͧ�� Ы��ط��դ�ҵ�� 0 - 360 ͧ�� Ѵ��ҡ��鹰ҹ��˹��ѡ��Դ� ��¡��˹��ѡ�� Ы��ط��ԧ, �Ы��ط��Դ, �Ы��ط��

�ʴ��ѡɳС��§�ͧ᡹�š

�ʴ��ٹ��ٵ� ��鹢�ҹ ��¹ ��¹��á

�ʴ��к��ԡѴ��ʵ��

�ʴ��ѡɳо�鹼�Ƿ��ʴ��çἹ��ٻ�ç��к͡ �ٻ�ç��¡�� ٻ�йҺ

�ʴ��çἹ��䫹� (Goode's Homolosine Projection) �� :
http://www.rmutphysics.com/sciencefac/artic/map/map.htm

��躷��¹ 1

��š

1. �к��Һ��š

��鹷��Ҥ��ҧ�ͧ�š �ժ�ǧ�� С�ҧ�׹��ç�ѹ�Դ�ҡ��˵��Ӥѭ ��

1.1 �š��ѳ�ҹ�ç�� 鹼��š�֧��Ѻ�ʧ�ҷԵ��ѹ

1.2 �š��ع�ͺ��ͧ��⤨��ͺ�ǧ�ҷԵ�� š��ع�ͺ��ͧ�ҡ��ȵ��ѹ��价�ȵ��ѹ�͡ ( �ͧ�ҡ��š��ѡɳзǹ��ԡ� )
��鹷��ҧ��ȵ��ѹ�͡��繴ǧ�ҷԵ��͹ ( ��ҧ��͹ )

2. �ͧ�Ԩٴ ( ��¹) �Ѻ�к��Һ��š �ͧ�Ԩٴ��¹ �դ��ѹ��Ѻ�к��Һ��š �ѧ��

2.1 ��һҹ��ҧ��չԪ ( G M T )

2.2 ��ѹ��ҡ� ( Date Line )

2.3 ࢵ��ҵðҹ�ͧ�š ( Standard Time Zone )

2.4 ��ҷ�ͧ�� ( Local Time )

2.5 ��ҵðҹ�ҡ� ( Standard Time )

3. ��Ӥѭ�ͧ�ͧ�Ԩٴ��¹

3.1 ��¹ ��Է��ҡ�ҡ��š�˹��仨ô��š�� ˹��ء��ҧ�ѹ 1 ͧ��ͧ�Ԩٴ �ç��ͧ�š�� 360 ͧ��
�ѧ��鹨֧��¹ 360 ��

3.2 �š��ع�ͺ��ͧ 1 �ͺ �� 360 ͧ�� 24 �� ع�ͺ��ͧ�ͧ�š��Թᴹ��ȵ�ҧ��Դ��ҡ�ҧ�ѹ��
��ҡ�ҧ�׹

3.3 �� 1 �� ˹觢ͧ�ǧ�ҷԵ��͹�ҡ��¹� 15 ͧ�� ͧ�Ԩٴ ��ͧ�Ԩٴ��ҹ��ѹ�͡��Ѻ�ʧ�ҷԵ��
��͹��ҹ��ѹ�� ѧ��Ң�ͧ�ա�š��ѹ�͡�֧��ǡ��Ҵ�ҹ��ѹ��

3.4 ��ͧ�Ԩٴ��ҧ�ѹ 1 ͧ�� ҵ�ҧ�ѹ 4 �ҷ�

�� 24 ��	š��ع�ͺ��ͧ 1 �ͺ	360 ͧ��
�� 1 ��	�š��ع��	15 ͧ��
�ء 15 ͧ��	��ҵ�ҧ�ѹ	1 ��
�ء 1 ͧ��	��ҵ�ҧ�ѹ	4 �ҷ�

��ػ �ء� 15 ͧ��ͧ�Ԩٴ ��Ҩе�ҧ�ѹ 1 �� ѧ��鹻��ȵ�ҧ�֧��ҷ�ͧ��ᵡ��ҧ�ѹ�� ͧ�ա�èѴ�к��Һ��鹷��ҧ�ͧ��鹷��š �� ҷ�ͧ�� ҵðҹ�ҡ�

4. ��һҹ��ҧ��չԪ ( GMT )

��һҹ��ҧ��չԪ ( Greenwich Mean Time : GMT ) ��ҷ�ͧ��蹢ͧ�Ӻš�չԪ ��ا�͹�͹ ��ѧ�� ¹�á
( 0 ͧ�� ) �ҡ��ҹ �١��˹��ҵðҹ�ҡŷ��ȵ�ҧ��ҧ�ԧ ��º��§��͡�˹��ҵðҹ�ͧ��ȵ�
��¡�ա��ҧ˹�� ҡ� ( Unversal Time )

��ҧ �� 20.00 � �ͧ�� ç�Ѻ 13.00 � ��һҹ��ҧ��չԪ��ҵðҹ�ҡš�չԪ ��һ��
��һҹ��ҧ��չԪ 7 ��

5. ��ѹ�� ( Date line )

5.1 ��ѹ�� ѹ��ҡ��ѹ�ҡ�(International Date Line ) ��Է��ҡ�Ѻ��¹�� 180 ͧ��ͧ�Ԩٴ ��觹ҹҪҵ�
��˹��ѹ�� ѹ�ҡ� ��Թ�ҧ��鹹��е�ͧ��¹�ŧ�ѹ��ѹ��ѹ��

* ��ѹ��ѹ�ҡ� ��ҡ��ҹ�蹴Թ��鹵ç��͹��¹��ҡ��ҵ��ࢵ��û��ͧ�ͧ��ȵ�ҧ�

5.2 ��ѹ�ҡ�价ҧ��ȵ��ѹ�� е�ͧ��ѹ 1 �ѹ ��Թ�ҧ�ҡ�Թᴹ��ҹ��ѹ�͡�ͧ��ѹ�ҡ� ��鹹��ѧ�Թᴹ
��ҹ��ѹ��е�ͧ��ѹ�ա 1 �ѹ

5.3 ��ѹ�ҡ�价ҧ��ѹ�͡ �е�ͧŴŧ 1 �ѹ ��Թ�ҧ�ҡ�Թᴹ��ҹ��ѹ��ͧ��ѹ�ҡ� ��鹹��ѧ�Թᴹ��ҹ��ѹ�͡�е�ͧŴ��ŧ 1 �ѹ

6. ࢵ��ҵðҹ�ͧ�š ( Standard Time Zone )

6.1 ࢵ��ҵðҹ�ͧ�š ��¡�ա��ҧ˹�� ࢵ�Ҥ�� ( Time Zone ) �� ҷ��˹��ࢵ�Ҥ��ҵ�ҧ��š
�շ�� 24 ࢵ �ءࢵ�Ҥ��ͧ�Ԩٴ��ҧ�ѹ 15 ͧ�� зء� 15 ͧ��ͧ�Ԩٴ ��Ҩ��¹� 1 ��

6.2 ��¹�á 0 ͧ��ͧ�Ԩٴ ��Ӻš�չԪ ��¹��ѹ��¹��ѹ�͡ �ա�� 180 ͧ��ͧ�Ԩٴ

6.3 ��¹�ҵðҹ ( Standard Meridian ) ��¹��ҧ�ѹ 15 ͧ��ͧ�Ԩٴ ��駴�ҹ��ѹ��д�ҹ��ѹ�͡ ��

� ��¹ 0 , 15 , 30 , 45 , 60 , 75 , 90 , 105 , 12� , 135 , 150 , 165 ,��180 ͧ��ͧ�Ԩٴ �ء��繵�ǡ�˹��ҵðҹ�ͧ
��ࢵ �ѧ��鹨֧��¡�� ҵðҹ

� ��¹�ҵðҹ��ҵ�ҧ�ѹ 1 �� зء��ҧ�ѹ 15 ͧ��ͧ�Ԩٴ