Mapping and GIS Solutions Community

I'm a non-professional (hobby) user, using a Trimble Catalyst DA2 to locate buried survey stations (OS triangulation stations from half a century ago) in the UK, using TerraFlex. The process needs sub metre accuracy. I've been copy-pasting the Eastings and Northings (1cm precision) across from a website, which works well but is a little fiddly. It would be more convenient to get the points across in bulk. I can import them to Connect via a kml file, and send them to TerraFlex as forms. However, I quickly discovered that the forms aren't accurately located - perhaps rounded to the nearest metre.

Hi Rob

What a great hobby. 
Sounds like a datum shift here. OS stations are based on OSGB36 ( equivalent to ETRS89) and KML uses WGS84. 
There is a difference between these two datums In the ball park you are describing so you'd need to perform some sort of transformation to remove this error

We can take this offline (happy to DM you) but I'd suggest the following workflow:

1. Download the QGIS (this is free open source GIS SW)
2. Get your OS Grid coordinates in a CSV format -  PointCode, Description, X,Y,Z 
3. Open QGIS > Data Source Manager > Delimiter text - follow this video here as an example how to import and georeference this Importing CSV (Excel) Coordinates into QGIS
   • NB the Geometry CRS (Coordinate Reference Systems) you need to define is  EPSG 27700 - OSGB36/British National Grid
4. Once Imported you can save the layer as a vector file choosing SHAPEFILE - again this is at the end of this video Importing CSV (Excel) Coordinates into QGIS
5. This shapefile can be zipped then Imported into Terraflex and should be correctly georeferenced 

Give me a shout If you need any further help and I can help you get setup

I'm a non-professional (hobby) user, using a Trimble Catalyst DA2 to locate buried survey stations (OS triangulation stations from half a century ago) in the UK, using TerraFlex. The process needs sub metre accuracy. I've been copy-pasting the Eastings and Northings (1cm precision) across from a website, which works well but is a little fiddly. It would be more convenient to get the points across in bulk. I can import them to Connect via a kml file, and send them to TerraFlex as forms. However, I quickly discovered that the forms aren't accurately located - perhaps rounded to the nearest metre.

Hi Rob

What a great hobby. 
Sounds like a datum shift here. OS stations are based on OSGB36 ( equivalent to ETRS89) and KML uses WGS84. 
There is a difference between these two datums In the ball park you are describing so you'd need to perform some sort of transformation to remove this error

We can take this offline (happy to DM you) but I'd suggest the following workflow:

1. Download the QGIS (this is free open source GIS SW)
2. Get your OS Grid coordinates in a CSV format -  PointCode, Description, X,Y,Z 
3. Open QGIS > Data Source Manager > Delimiter text - follow this video here as an example how to import and georeference this Importing CSV (Excel) Coordinates into QGIS
   • NB the Geometry CRS (Coordinate Reference Systems) you need to define is  EPSG 27700 - OSGB36/British National Grid
4. Once Imported you can save the layer as a vector file choosing SHAPEFILE - again this is at the end of this video Importing CSV (Excel) Coordinates into QGIS
5. This shapefile can be zipped then Imported into Terraflex and should be correctly georeferenced 

Give me a shout If you need any further help and I can help you get setup

I'm a non-professional (hobby) user, using a Trimble Catalyst DA2 to locate buried survey stations (OS triangulation stations from half a century ago) in the UK, using TerraFlex. The process needs sub metre accuracy. I've been copy-pasting the Eastings and Northings (1cm precision) across from a website, which works well but is a little fiddly. It would be more convenient to get the points across in bulk. I can import them to Connect via a kml file, and send them to TerraFlex as forms. However, I quickly discovered that the forms aren't accurately located - perhaps rounded to the nearest metre.

Hi Rob

What a great hobby. 
Sounds like a datum shift here. OS stations are based on OSGB36 ( equivalent to ETRS89) and KML uses WGS84. 
There is a difference between these two datums In the ball park you are describing so you'd need to perform some sort of transformation to remove this error

We can take this offline (happy to DM you) but I'd suggest the following workflow:

1. Download the QGIS (this is free open source GIS SW)
2. Get your OS Grid coordinates in a CSV format -  PointCode, Description, X,Y,Z 
3. Open QGIS > Data Source Manager > Delimiter text - follow this video here as an example how to import and georeference this Importing CSV (Excel) Coordinates into QGIS
   • NB the Geometry CRS (Coordinate Reference Systems) you need to define is  EPSG 27700 - OSGB36/British National Grid
4. Once Imported you can save the layer as a vector file choosing SHAPEFILE - again this is at the end of this video Importing CSV (Excel) Coordinates into QGIS
5. This shapefile can be zipped then Imported into Terraflex and should be correctly georeferenced 

Give me a shout If you need any further help and I can help you get setup

I'm a non-professional (hobby) user, using a Trimble Catalyst DA2 to locate buried survey stations (OS triangulation stations from half a century ago) in the UK, using TerraFlex. The process needs sub metre accuracy. I've been copy-pasting the Eastings and Northings (1cm precision) across from a website, which works well but is a little fiddly. It would be more convenient to get the points across in bulk. I can import them to Connect via a kml file, and send them to TerraFlex as forms. However, I quickly discovered that the forms aren't accurately located - perhaps rounded to the nearest metre.

Hi Tom

Your suggested workflow worked well. I imported c. 9300 points in 10 batches. Not that I'm likely to visit them all!

As a check, the forms locations matched the 1cm coordinates pasted into Terraflex for the few where I used 1cm Catalyst, when I tested them this weekend.

It's impressive that these buried survey points installed in the 1950s are pretty close to the Ordnance Survey's calculated locations. 

Thanks again.
Rob

Hi Rob

What a great hobby. 
Sounds like a datum shift here. OS stations are based on OSGB36 ( equivalent to ETRS89) and KML uses WGS84. 
There is a difference between these two datums In the ball park you are describing so you'd need to perform some sort of transformation to remove this error

We can take this offline (happy to DM you) but I'd suggest the following workflow:

1. Download the QGIS (this is free open source GIS SW)
2. Get your OS Grid coordinates in a CSV format -  PointCode, Description, X,Y,Z 
3. Open QGIS > Data Source Manager > Delimiter text - follow this video here as an example how to import and georeference this Importing CSV (Excel) Coordinates into QGIS
   • NB the Geometry CRS (Coordinate Reference Systems) you need to define is  EPSG 27700 - OSGB36/British National Grid
4. Once Imported you can save the layer as a vector file choosing SHAPEFILE - again this is at the end of this video Importing CSV (Excel) Coordinates into QGIS
5. This shapefile can be zipped then Imported into Terraflex and should be correctly georeferenced 

Give me a shout If you need any further help and I can help you get setup

I'm a non-professional (hobby) user, using a Trimble Catalyst DA2 to locate buried survey stations (OS triangulation stations from half a century ago) in the UK, using TerraFlex. The process needs sub metre accuracy. I've been copy-pasting the Eastings and Northings (1cm precision) across from a website, which works well but is a little fiddly. It would be more convenient to get the points across in bulk. I can import them to Connect via a kml file, and send them to TerraFlex as forms. However, I quickly discovered that the forms aren't accurately located - perhaps rounded to the nearest metre.