Shifting utilities point & line objects based on cadastral boundaries

Hi,

Do you know how much distance you have to move? or is it some kind of vector georeferencing?

Can you add some screenshot for better understanding

Hi Pratap

It's not a consistent shift across the cadastre so the distance will be quite variable. In some places a shift won't be required, in others it may range up to 15mts.

I've attached a screenshot. Red is the old cadastre, blue is the new cadastre and the pink lines & points represent pipes & manholes.capture.jpg

Regards

Craig

Hi,

Use Offsetter initially and move entire data to the nearest point (seems to be same at all locations) and then use AnchoredSnapper for accurate movement of features

My intention of using offsetter is to bring the features within small radius such that spatial query by anchorsnapper will be effective

@craig, if you could share some data as @todd_davis mentioned that would be great,

This is one case where FME on its own might not be the best solution - full disclosure, I work for Esri, but I know Safe will appreciate the candor. If you have ArcGIS Desktop Advanced then take a look at Generate Rubbersheet Links and Rubbersheet Features. Just the links from the first tool can be used to warp non-linear features with the RubberSheeter transformer. That would be the easy-button approach anyway. If you are a perfectionist you would go the route of using the survey observations of your cadastre to correct your parcel boundaries then borrow those shifts to adjust the dependent features. ArcGIS has that workflow too with a parcel fabric.

If you want to do this in FME, I think it comes down to whether the features on the cadastral layers have ID numbers where you can identify each feature in both versions.

If you can then what you need to do is create a line feature between the original and new points on each feature, to create control features. Then you can rubbersheet the pipeline data.

I've attached a workspace - cadastraloffset.fmw that does that. It only has 1 cadastral feature, and it assumes there are the same number of features on each cadastre layer in the same order. If not, you should remove features that don't appear in the other layer (Matcher transformer?) and sort the data into order (Sorter).

I'm about 80% certain this would work. My example has a fixed offset, whereas yours is variable, but that's just because it was easier to create an example like that. It will still work.

Otherwise I would - reluctantly - agree with Bruce. Others have suggested the AnchoredSnapper, but I don't think this is a viable solution for your problem. You don't want to snap the pipeline and you don't really want to snap the second cadastral dataset. You just need to know what the offsets are between the two, and use that to rubbersheet the pipeline.

Thank you all for your ongoing responses, much appreciated.

The following gives a little more background into the issue I'm facing.

Prior to my time, the organisation decided to maintain its own cadastral/parcel fabric. This was done using less than ideal bearing and distance tools, digitizing, and some 'hand drawing' thrown in for good measure.

Polygons were created in the land parcel layer to represent 'artificial' boundaries around infrastructure items. Road corridors were also 'combined' into the layer. Many consequent map layers (several hundred or more) were developed using the 'in-house' parcel fabric as a reference.

To reduce the ongoing overhead of having to maintain this cadastre, it is our intention to adopt government maintained/supplied cadastre which is far superior in its spatial accuracy than our own.

We're also encountering issues as we attempt to consume spatial data from other government departments or external sources due to the significant difference in spatial accuracy.

Any spatial analysis is problematic to say the least.

I use MapInfo, QGIS and FME and also have access to ArcGIS.

I've attached clipped datasets of an example area.

Regards

Craig

datasets.zip

Hi Lyes

I've used FME's coordinate extractor to create points from vertices and attributed them with x & y coords.

Regards

Craig

I meant coordinates from a surveyor or accurate GPS (sorry for the misundertanding)

Had a look at this and fired a couple of scripts over it. I would suggest that if you do plan to go down this path that you spend a significant time with planning it and testing. I did what I mentioned above but there are several things I would add if I was doing this for an official outcome. As I was checking line against lines, rather than parcel against parcel, I said that the boundaries couldn't exceed 20% difference in length but I think a maximum angle difference is also very important. You actually don't want to take into account some of the real erroneous data, as it provides a skew. I also found that the natural boundaries (in my approach) caused a bit of difficulty and would need to be taken into account.

The data is vastly different with significant vertex difference and that caused some trouble for me.There are a few error in here as well and I will admit I deleted quite a few around curve/natural boundaries due to the large difference between the datasets

Attached are the movements between the layers and the what the pipes manholes look like after going through rubbersheeter set to distance 30output.zip

Hi Todd

Thank you for looking into this, I appreciate your time. What's becoming apparent is that it's going to be a hard nut to crack due to the reasons you've highlighted. I'm thinking I may need to process much smaller geographic areas.

Regards

Craig