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ArcGIS to SQL Server projection problem RRS feed

  • Question

  • I have a dataset which uses the NAD_1927_UTM_Zone_17N coordinate system.

    Due to the fact that the dataset locality still uses imperial measurements in its maps and surveying, the dataset has a linear unit measurement of one foot (0.3048 metres).  This in itself is fine, as all of the other datasets are the same and ArcMap understands that the linear unit is different and places the objects correctly in the 'real world'.

    I've tried uploading this data to SQL Server (using the Shape2SQL tool) and, by the look of it, SQL Server is treating the (hidden) geometric measurements as metres - as is normally the case for this coordinate system.  As such, the objects are being placed in completely the wrong place on the map.

    I'm not too sure where to start in order to account for this discrepancy, or whether it can be dealt with at all in SQL or prior to the load.

    Does anyone have any recommendation?

    Tuesday, November 19, 2013 4:53 PM

Answers

  • Hi DJ Matt,

    According to your description, ArcMap has a different linear unit measurement. You upload the data to SQL Server with the default unit, then export these values to show the place in the map.  The location of the objects will show the wrong place in the map due to the different measurement. About this projection problem, I recommend you can convert the  source data manually before you prepare to upload them. Or in SQL Server, you can  recalculate the uploaded data according to the projection formula and save the new numeric data to an temple table, and then export these new data to show the location of the object.

    For example, if the default  linear unit measurement of one foot is 0.3048 meters, and the foot is 0.502 meters in ArcMAp. You can refer to the following T-SQL Statement.

    With cte (newcolumn1, newcolumn2) 
     as (select column1 *0.3048/0.502 as newcolumn1, column2 *0.3048/0.502 as newcolumn2 from table1)
    
    Select * from cte

    Thanks,
    Sofiya Li


    Sofiya Li
    TechNet Community Support

    • Marked as answer by Sofiya Li Thursday, November 28, 2013 6:27 AM
    Friday, November 22, 2013 3:30 AM