Spatial domain of featuredataset within personal geodatabase to large

[KatharinaBrüser]

I created a personal geodatabase in which I want to import GPS-derived features (with trimble gps Analyst extension). for the databese I chose geographic cordinate system  in WGS84 and set the xy domain to the default values min = -400 (for both x and y) and max = 400. However, when creating a new feature dataset within the *.mdb, setting the same projection (or importing it) the resulting domain has higher maximum values for x and y (= 9006799.25474099 instead of 400).
I can't see why this is happening, or how I can change it as it is not possible to define the spatial domain itself when creating the dataset, nor change it within the properties.

Since the spatial domain of the database is smaller than the one of the dataset, I get an error when importing GPS derived features for postprocessing purposes.


Thanks for any advice
Katharina

[curtvprice]

1) If you don't have a good reason to do otherwise, the file geodatabase (.gdb) is a much better choice than .mdb, which although includes much of the same functionality, is more limited and many quirks compared to the file geodatabase.

2) You may want to set the XY domain by creating the feature class before you load the data. You can control the maximum coordinates by altering the resolution (which is the coordinates used -- different than the XY tolerance used for geoprocessing)

Here's the online help page on this topic
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//003n0000001z000000.htm

3) Are you sure you are working in projected coordinates? -400 to 400 doesn't sound like a projection I'm familiar with...

[MelitaKennedy]

I created a personal geodatabase in which I want to import GPS-derived features (with trimble gps Analyst extension). for the databese I chose geographic cordinate system  in WGS84 and set the xy domain to the default values min = -400 (for both x and y) and max = 400. However, when creating a new feature dataset within the *.mdb, setting the same projection (or importing it) the resulting domain has higher maximum values for x and y (= 9006799.25474099 instead of 400).
I can't see why this is happening, or how I can change it as it is not possible to define the spatial domain itself when creating the dataset, nor change it within the properties.

Since the spatial domain of the database is smaller than the one of the dataset, I get an error when importing GPS derived features for postprocessing purposes.


Thanks for any advice
Katharina

Katharina,

The large values are correct. In a high precision feature class/dataset, the maximum allowed value is around 9000 trillion as an integer value. The XY/Z/M domains and resolution values convert between the real world double precision values and internally managed positive integers. That's with a resolution size of 1. When we set the XY (Z/M) domain minimum and maximum values to something reasonable, that means the resolution value is very, very small which increases storage requirements and processing time. Instead, only the minimum XY/Z/M domain values are used plus a more reasonable resolution values. The maximum values are set based on the minimum values and the resolution, and thus the maximum values become very large.

You may want to take a look at this white paper:

Understanding Coordinate Management in the Geodatabase

Melita

[KatharinaBrüser]

Thanks to both of you,

both the link and the whitepaper were really helpful.

I had to use a personal database though, since the GPS Analyst Extension only works with that one.