All,
I'm straying into territory I am not so familiar with, creating a custom geographic transformation and need help. I'm working on data for Bangladesh. Up until now I've been working with data primarily in:
I recently received a dataset in this coordinate system:
I believe this to be the Bangladesh Transverse Mercator (BTM) as describe on this blog page here. At the bottom of this page a Khaled responds to the blog and gives the 3 parameters required for the transformation. Now I've never done anything like this so looking at desktop help I ran the Create Custom Geographic Transformation tool and filled it in as shown below:
Attachment 30988
But when I go into the AppData\Roaming\ESRI\Desktop10.2\ArcToolbox\CustomTransformations folder and open the gtf file I see that the 3 parameters are set to zero as shown below, why is this? What have I done wrong? Am I even doing this right?
GEOGTRAN["BTM_to_UTM",GEOGCS["GCS_Everest",DATUM["D_Everest",SPHEROID["Everest_Adjustment_1937",6377276.345,300.8017]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],METHOD["Geocentric_Translation"],PARAMETER["X_Axis_Translation",0.0],PARAMETER["Y_Axis_Translation",0.0],PARAMETER["Z_Axis_Translation",0.0]]
Now I edit this file and change the 3 parameters as shown below (may be this is the wrong thing to do?):
GEOGTRAN["BTM_to_UTM",GEOGCS["GCS_Everest",DATUM["D_Everest",SPHEROID["Everest_Adjustment_1937",6377276.345,300.8017]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],METHOD["Geocentric_Translation"],PARAMETER["X_Axis_Translation",–283.7],PARAMETER["Y_Axis_Translation",–735.9],PARAMETER["Z_Axis_Translation",–261.1]]
I then go into the dataframe properties go to coordinates and select the transformation and select my BTM to UTM .I notice even though I had set the values (which may be the totally wrong thing to do) I would have at least expected to see them next to the Method but they are all zero as shown below.
Attachment 30989
I'm using ArcGIS 10.2 and have been able to replicate this problem on a 10.2.1 machine.
Any help would be very much appreciated!
Duncan
I'm straying into territory I am not so familiar with, creating a custom geographic transformation and need help. I'm working on data for Bangladesh. Up until now I've been working with data primarily in:
WGS_1984_UTM_Zone_45N
WKID: 32645 Authority: EPSG
Projection: Transverse_Mercator
false_easting: 500000.0
false_northing: 0.0
central_meridian: 87.0
scale_factor: 0.9996
latitude_of_origin: 0.0
Linear Unit: Meter (1.0)
Geographic Coordinate System: GCS_WGS_1984
Angular Unit: Degree (0.0174532925199433)
Prime Meridian: Greenwich (0.0)
Datum: D_WGS_1984
Spheroid: WGS_1984
Semimajor Axis: 6378137.0
Semiminor Axis: 6356752.314245179
Inverse Flattening: 298.257223563
I recently received a dataset in this coordinate system:
Everest_Transverse_Mercator
Authority: Custom
Projection: Transverse_Mercator
false_easting: 500000.0
false_northing: -2000000.0
central_meridian: 90.0
scale_factor: 0.9996
latitude_of_origin: 0.0
Linear Unit: Meter (1.0)
Geographic Coordinate System: GCS_Everest
Angular Unit: Degree (0.0174532925199433)
Prime Meridian: Greenwich (0.0)
Datum: D_Everest
Spheroid: Everest_Adjustment_1937
Semimajor Axis: 6377276.345
Semiminor Axis: 6356075.41314024
Inverse Flattening: 300.8017
I believe this to be the Bangladesh Transverse Mercator (BTM) as describe on this blog page here. At the bottom of this page a Khaled responds to the blog and gives the 3 parameters required for the transformation. Now I've never done anything like this so looking at desktop help I ran the Create Custom Geographic Transformation tool and filled it in as shown below:
Attachment 30988
But when I go into the AppData\Roaming\ESRI\Desktop10.2\ArcToolbox\CustomTransformations folder and open the gtf file I see that the 3 parameters are set to zero as shown below, why is this? What have I done wrong? Am I even doing this right?
GEOGTRAN["BTM_to_UTM",GEOGCS["GCS_Everest",DATUM["D_Everest",SPHEROID["Everest_Adjustment_1937",6377276.345,300.8017]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],METHOD["Geocentric_Translation"],PARAMETER["X_Axis_Translation",0.0],PARAMETER["Y_Axis_Translation",0.0],PARAMETER["Z_Axis_Translation",0.0]]
Now I edit this file and change the 3 parameters as shown below (may be this is the wrong thing to do?):
GEOGTRAN["BTM_to_UTM",GEOGCS["GCS_Everest",DATUM["D_Everest",SPHEROID["Everest_Adjustment_1937",6377276.345,300.8017]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],METHOD["Geocentric_Translation"],PARAMETER["X_Axis_Translation",–283.7],PARAMETER["Y_Axis_Translation",–735.9],PARAMETER["Z_Axis_Translation",–261.1]]
I then go into the dataframe properties go to coordinates and select the transformation and select my BTM to UTM .I notice even though I had set the values (which may be the totally wrong thing to do) I would have at least expected to see them next to the Method but they are all zero as shown below.
Attachment 30989
I'm using ArcGIS 10.2 and have been able to replicate this problem on a 10.2.1 machine.
Any help would be very much appreciated!
Duncan