Latest Contributions by ChrisDonohue__GISP

Not sure if this will give you what you need, but I found this on a quick web search: AGD66 to WGS 84 (16) (note:  Google seems to correlate WGS66 with AGD66, which may or may not be correct). Some general information (but not the specific transformation): World Geodetic System - Wikipedia, the free encyclopedia Melita Kennedy Edit: added more info Chris Donohue, GISP ... View more

To expand on what Adrian Welsh mentioned, there are many organizations that seek help with GIS work and are looking for help, even from folks with little background.  There's tons of "simpler" GIS tasks that need to be done, like digitizing, that organizations need and are willing to bring in someone and train. Many of these are government and non-profit organizations.  And in terms of timing, now is a good time to look for these types of jobs, as many organizations staff up for the summer.  For example, many government organizations have internships available in the summer that open up for application now (and some are only open to students currently attending college).  And it is not just government - private firms that deal with field studies often need extra help in the summer months to help in study setup and then work with the data as it rolls in from the field crews. Some specific resources: If you are a member of the Society of Conservation GIS, they have a job board that often has internships. Society for Conservation GIS Also, of course, if you want to go all-out, there is this: Student Opps Common Questions - ESRI Internships (paid!) Chris Donohue, GISP ... View more

If Python is not your thing, another possible approach would be to use the Feature Compare tool Feature Compare—Help | ArcGIS for Desktop Chris Donohue, GISP ... View more

I don't know if this is the case for your data, but the ESRI tool help does mention that the tool uses an adaptive tiling process to handle large datasets. The availability of physical memory may limit the amount (and complexity) of input features that can be processed and dissolved into a single output feature. This limitation could cause an error to occur, as the dissolve process may require more memory than is available. To prevent this, Dissolve may divide and process the input features using an adaptive tiling algorithm. To determine the features that have been tiled, run the Frequency tool on the result of this tool, specifying the same fields used in the dissolve process for the Frequency Field(s) parameter. Any record with a frequency value of 2 has been tiled. Tile boundaries are preserved in the output features to prevent the creation of features that are too large to be used by ArcGIS. ArcGIS Help 10.1 Dissolve (Data Management) Chris Donohue, GISP ... View more

It sounds like the objective is create addresses for parcels, given a known start and end value.  The script  Joe Borgione mentions works well - I've used it many times. Notes on script: pStart is the starting value.  Put in the first address value here. pInterval is the interval between values.  So if your addresses are say 10 apart, you would use 10 here. If pInterval is variable for each street, you will have to either manually calculate the range or add some more coding to do the calculation. Chris Donohue, GISP ... View more

Subtypes are typically used to ensure data validity.  Representations, on the other hand, are specifically employed in displaying data.  Representations allow more display options than the standard symbology, and in particular are helpful in that they allow one to display data in different ways without altering the source data.  For example, if one had two coincident lines in GIS to display, like bus routes on the same road, with Representations one could show them side-by-side for reader clarity instead of overlapping each other.  And the original data would not need to be altered to do this. Chris Donohue, GISP ... View more

You mention you are doing this in Python.  Can you post your code so it can be evaluated?  If it is just a one-liner, a screenshot will do.  If it is longer, see the following link for how to post code in GeoNet, as it is not intuitive: Code Formatting... the basics++ Having the code posted in the correct formatting will help GeoNet users troubleshoot the issue. Python Chris Donohue, GISP ... View more

Also, there used to be the easy-to-remember site seamless.usgs.gov, but that site is also gone.  Now it leads to the USGS National Map site, which likely has it, but one will have to dig a bit. The National Map Chris Donohue, GISP ... View more

For many years there was a seamless topo quad collection for all of California at the California Spatial Information Library (CASIL) at  gis.ca.gov.  However, CASIL has been replaced in recent years by the California State Geoportal.  You may be able to locate it on the Geoportal (though I was not able to quickly find it). Geoportal Chris Donohue, GISP ... View more

This pdf from back in the days when geodatabase topology was new (2003) may help in understanding how it differs from ArcInfo topology.  It contrasts geodatabase topology with ArcInfo topology to some extent. https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0ahUKEwiAz6eg0oHLAhVBU2MKHTqiDNEQFggmMAI&url=http%3A… The very last paragraph of that pdf states this: Geodatabase topology stores very little information in the database.  Only the parameters of the topology (e,g., participating feature classes, cluster tolerance, relative ranks, and rules), dirty areas, errors, and exceptions are stored.  All information is discovered on the fly during the manipulation of the participating feature classes. Chris Donohue, GISP ... View more

To expand on what Dan Patterson pointed out, from the link he posted: The number of the noncorrelated control points required for this method must be 1 for a zero-order shift, 3 for a first order affine, 6 for a second order, and 10 for a third order. Chris Donohue, GISP ... View more

One issue to be aware of regarding SID images - they are a proprietary format.  ArcGIS can read them, but I believe one cannot export new SID images without purchasing software from LizardTech. MrSID - Wikipedia, the free encyclopedia Chris Donohue, GISP ... View more

In explanation for Union their is this statement: License: With ArcGIS for Desktop Basic and Standard licenses, the number of input feature classes or layers is limited to two. So for example if you wanted to Union 40 feature classes, you can't do them all in one shot. Edit - Dan Ninja'd me again  Chris Donohue, GISP ... View more

This may be of help: http://help.arcgis.com/en/arcgisdesktop/10.0/pdf/linear-referencing-tutorial.pdf Chris Donohue, GISP ... View more