topic Re: Transforming polygon from GCS_Arc_1960/Arc_1960_UTM_Zone_37S to GCS_WGS_1984/WGS_1984_UTM_Zone_37S? in Coordinate Reference Systems Questions

Transforming polygon from GCS_Arc_1960/Arc_1960_UTM_Zone_37S to GCS_WGS_1984/WGS_1984_UTM_Zone_37S?

JohnMutua — Sun, 24 Feb 2019 13:42:38 GMT

Melita Kennedy have a polygon which is in GCS_Arc_1960/Arc_1960_UTM_Zone_37S coordinate system and I need to transform it to to GCS_WGS_1984/WGS_1984_UTM_Zone_37S. I have not been successful in doing this using ArcMap. Is there a solution for this? if possible provide a complete workflow.

Re: Transforming polygon from GCS_Arc_1960/Arc_1960_UTM_Zone_37S to GCS_WGS_1984/WGS_1984_UTM_Zone_37S?

DanPatterson_Retired — Sun, 24 Feb 2019 14:00:07 GMT

Project—Data Management toolbox | ArcGIS Desktop

is pretty clear, but make sure you specify a datum transformation if offered one. They work in both directions

Were you getting an error message or something?

Re: Transforming polygon from GCS_Arc_1960/Arc_1960_UTM_Zone_37S to GCS_WGS_1984/WGS_1984_UTM_Zone_37S?

JohnMutua — Sun, 24 Feb 2019 17:26:44 GMT

Process goes on smoothly but the output cannot cannot be visualised in the viewer. What could be the problem?

Re: Transforming polygon from GCS_Arc_1960/Arc_1960_UTM_Zone_37S to GCS_WGS_1984/WGS_1984_UTM_Zone_37S?

DanPatterson_Retired — Sun, 24 Feb 2019 17:34:54 GMT

right click on the layer and select Zoom to layer.

The file could have been defined wrong and projecting it made it worse.

The best thing to do, is right-click on the layer, and select Properties, then examine the Extent of the layer.

If the left, right, top and bottom are in the range -180, 180 and -90, 90, then the coordinates of the file are in decimal degrees, If that file was defined as a UTM, then it was done incorrectly and it should have been defined as a GCS (geographic coordinate system.)

Before you start swimming around in the sea of Define vs Project, report the Extent of the file you are working with so guessing as to you situation can be removed

Re: Transforming polygon from GCS_Arc_1960/Arc_1960_UTM_Zone_37S to GCS_WGS_1984/WGS_1984_UTM_Zone_37S?

JohnMutua — Sun, 24 Feb 2019 17:46:36 GMT

Thanks Dan Patterson‌ I now understand the problem. Here is the extend of the file Top: 2218.268208 m, Right: 1859.119141 m, Bottom: 972.398177 m, Left: 962.439880 m. Which coordinate system could this be?

Re: Transforming polygon from GCS_Arc_1960/Arc_1960_UTM_Zone_37S to GCS_WGS_1984/WGS_1984_UTM_Zone_37S?

DanPatterson_Retired — Sun, 24 Feb 2019 17:55:26 GMT

Well... could be none, You indicate the southern hemisphere, so it certainly isn't utm or decimal degrees. Maybe you had better examine the source of the data, perhaps there is some metadata, or it is the result of digitizing off an unreferenced image or map.

In any event, it is pretty useless unless you can tie it into some coordinate system used in your area.

Re: Transforming polygon from GCS_Arc_1960/Arc_1960_UTM_Zone_37S to GCS_WGS_1984/WGS_1984_UTM_Zone_37S?

JohnMutua — Sun, 24 Feb 2019 17:59:31 GMT

Thanks, I will have to go to the field and collect control points for georeferencing.