Differences

This shows you the differences between two versions of the page.

--- georef [2021/03/10 23:14] – [Coordinate Conversion] allchin09
+++ georef [2021/03/11 00:31] (current) – [Coordinate Conversion] allchin09
@@ Line 131: / Line 131: @@
 | scale factor   | 1             |              |
-Other relevant values
-| zone 8      |
+On these maps, Sydney Observatory was used as a datum for triangulation, with the following values:
+^Format ^Latitude          ^Longitude         ^
+|DMS    |S 33d 51m 41.10s  |E 151d 12m 17.85s |
+|DD     |S 33.861417d      |E 151.204958d     |
+The [[http://www.ga.gov.au/ngrs/imf.jsp?site=ngrs|NGDB]] provides the following values of the observatory in different datums:
+^Datum  ^Latitude            ^Longitude           ^Easting       ^Northing   ^
+|Clarke |S33°51' 41.107"     |E151°12' 17.993"    |420746.19     |816789.65  |
+|AGD66  |S33°51' 40.2924"    |E151°12' 12.3136"   |333809.38     |6251769.51 |
+|AGD84  |S33°51' 40.3241"    |E151°12' 12.2557"   |333807.91     |6251768.51 |
+|GDA94  |S33°51' 34.610232"  |E151°12' 16.470597" |333913.76     |6251959.42 |
 Note:
@@ Line 225: / Line 235: @@
     * Converting into metres is 400,000 / 0.91439841 = 365,759.36 metres
-== Headline ==
+== +y_0 ==
+  * Description: False northing
+  * Value: 731518.73
+  * Value description:
-^Parameter    ^Parameter Description          ^Parameter Value  ^Value Description    ^Value Comment              ^
+    * ANG has a false northing of 800,000 yards south of the true origin
-|+proj        |Projection name                |tmerc            |Transverse Mecator   |Type of project used in ANG|
+    * Converting into metres is 800,000 / 0.91439841 = 731,518.73 metres
-|+lat_0       |Latitude of projection centre  |34s              |||
-|+lon_0       |Longitude of projection centre |151e             |||
-|+k_0         |Scale factor                   |1                ||1 is also default value|
-|+a           |Semimajor radius of the ellipsoid axis |6378339.78||Value in british feet converted to metres|
-|+rf          ||294.26|||
-|+to_meter    |Horizontal unit value          |0.91439841|Length of a yard in metres |Yard used on coordinate grid|
-|+x_0         |False easting                  |365759.36|||
-|+y_0         |False northing                 |731518.73|||