Introduction to the Cadastral Editor in ArcGIS Survey Analyst 9 2

hi my name is Tim Hudson and I'm a product engineer with the software development group in Redlands California with me today is Chris B Scalia who also works on my team Chris and I both work on the survey analyst extension to ArcGIS we'd like to welcome you today to this live training seminar that introduces the cadastral editor cadastral editor is a new part of the arcgis survey last extension and today's seminar we will discuss four main topics first we will cover some background information on land Information Systems then we'll present a new kind of data set called the cadastral fabric how to add new land records to this data set and finally how to make use of the data to improve the coordinate positions represented by the canal fabric throughout the presentation we'll be presenting examples on how to use the cadastral editor tools through software demonstrations and we will also have review periods followed by a question and answer session being which time Chris will be answering some of your questions today in the interest of time there will not be a Q&A session directly after the first topic but you can start sending in your questions whenever you like we'll have the Q&A session after the second third and fourth topics let's get started with a first topic some background and land information systems well what is a land information system a land information system or lis for short is any system with a focus on managing information about land ownership and Taxation the type of information managed includes firstly the legal description of the land in question in other words what is the shape in size of the land and where is this land located geographically there is a strong spatial component to the legal description secondly the title defining who owns the land thirdly information about easements easements are used when someone other than the owner has certain rights other parts of the land a good example of use is for the placement and access to utilities for example an electric company owns the right to place power lines across property lastly property values are also managed for the purposes of land taxation formation under these four categories are referred to as cadastral and records and collateral and records are managed within a land information system all of these elements are equally important in an Al is the technology we describe today however has a focus on the first element the legal description of land we're focused on this presentation on the development of an accurate spatial framework to be used as a base on which to build these other elements of an an information system he maintains kadesha records well here are some examples I'll just run through these quickly large government organizations that have a big cadastral authorities mini cities manage a good natural base map that is used by other GS departments within that city departments of transportation and utility companies these last two usually focus on easements and rights-of-way what the cadastral records look like here is one example this is a subdivision plan describing the shape and size of four parcels of land this is a legal description prepared by the severe and you can see that it is very spacial in nature it looks like a map there are bearings and distances on this document there are references to points there are references to neighboring land and of course a reference to the parent property being subdivided at this point I want to introduce you to the collateral editor international fabric I will be moving straight into the second topic but before I do that we're going to take a quick peek at the Gatchell fabric as it shows up in our catalog as I mentioned before please feel free to send in your questions at this time well here we are in our catalog and you can see here that I have a file geodatabase inside of which we have a series of different data sets these are these are featured data sets over here and featured data sets contain feature classes all of these feature classes within this in this feature data set have the same coordinate system and projection defined on the feature dataset this kogo source data this all of the state in this these feature classes were used to build my collateral fabric the Glacial fabric is located right here if I open up the properties of my natural fabric we can take a look at the fabric classes when effect when the commercial fabric is created a series of tables are represented for this commercial fabric we have a control point table we have a points table lines table parcels table plans table and so on if I open if I connect or click on my plans fabric class you can see that I have a number of system attributes that are automatically created form for me so the cadastral fabric classes have some system attributes just like standard feature classes I can also enter additional attribute information to these classes in this case I'm going to add a source attribute and I'm going to add it as a standard text field do and identify on one of these parcels you can see here em identify results that I have a parcel called 0 1 1 and it has associated with it a series of lines the lines have bearing and distance information from points and two points in these from points in two points are also represented on for this particular line so I can click on one of these points and see its coordinates okay I'm going to flip back to the slides and keep going we'll delve into the commercial fabric a bit more or more in the next stop next demo for the second topic the commercial editor is a new part of the survey Alice extension product here you see the existing technology that includes the survey editor for processing raw field observations this technology has been available since our GS 8 3 the cadastral editor is in addition to the survey honest extension that was released with service pack 3 arcgis 9 - the cadastral editor technology was built together with an australian software development company called geo data when we started development of this technology our goal was to build a simple system that would provide a new type of data set to store and manage land records in a geo database we wanted to provide technology that enables our users to create and maintain an accurate spatial framework for a land information system be able to process survey derived coordinates and commercial land records in a productive editing environment to ultimately allow us to improve and maintain the accuracy of boundary geometry for land parcels recognize that a data set used as a base map for other GIS layers would require means to also update these other gr Slayers to keep them spatially in sync with the base map data set these are the five goals that we've worked towards with the development of the national editor the so the so called base map data set is called the cadastral fabric only the commercial editor can be used to edit this casual fabric well what is this commercial traffic firstly you can think of it as a surface of connected parcels that have overlapping boundaries but that share common points you can also think of the cadastral fabric as a network of connected parcel boundary lines the legal description bearings and distances are stored on these lines so you can think of the fabric as a surface of connected parcels in a dimensioned boundary network the Glacial fabric has an explicitly stored topology for parcels 37 and 36 the fabric dataset stores four lines for each parcel there are two overlapping lines where these parcels meet the fabric only stores two points at the ends of the lines where these parcels meet the points are shared by our parcels this means that there may be multiple lines between the same two points in other words there are a lot of redundant lines this is one form of redundancy there are other forms but for now it's enough to know that this redundancy is necessary in order to achieve spatial accuracy more on this later the common modern method for surveyors to define highly accurate positions on physical marks such as iron pins and monuments that define the corners of parcels is by using GPS GPS can provide very accurate coordinates in a projected coordinate system the cadastral fabric technology allows the day to defined by this modern cell a technique that is accurate projective coordinates to be integrated with the older land record data that is more historical in nature that is the bearings and distances from the older collateral records control points are not always directly tied to parcel corners often they are the Street intersection for example connection lines allow you to tie parcel corners to these control points this connection information is on the original record it could be represented by a street width for example next I want to explain a little more about how the cadastral fabric data is stored all the information is held in a set of tables each of these gray boxes here represent a table from the connectional fabric the first table I will describe is the plans table every legal document that represents one or more parcels can be stored as a single record in the plans table that single record holds information about the date of the survey the name of the severe and so on it stores information about the whole legal document in this case we have a single record representing a cranes roost subdivision each plan can represent one or more parcels here parcel 28 has been added to the parcels table you can see that is that it is referenced by the plans table parcels can only ever belong to a single plan you can see here that we have an ID for the screens roofs plan of 1 in the plans table and the plan ID is referencing this plan this planned parcel at this parcel this plan ID is referenced by this one that's also represented here and in the plans table so you can see that this parcel is represented by that plan parcel 27 is added to the same table and is also held in the cranes roost plan each parcel is defined by a set of recorded lines the lines table will hold the lines from many parcels you can see here that the lines that define parcel 27 have the parcel ID of that parcel in this case it's parsley 101 for each of these lines builds parcel 27 with the parcel ID of 101 each line is also defined at each end by a point that is stored as a record in the points table the latest computed point location is stored as attributes in the points table K you can see that the line 200 makes reference to the from and T points for the line the control table stores control point coordinates in order to be used in updating point coordinates a control point needs to be linked to a point in this case you can see that the control point called CP 1 is linked with the point 302 in the fabric the coordinates of the point and the control may be different to start out with prior to any adjustments for this reason the control table also stores coordinate attributes so here you can see in the points table we have XY and Z attributes for the points and in the control table we have XY and z coordinates for the control point in this case CP 1 finally for the table I'm going to use a little graphic here this is little for the line points table what are line points this is best described with a picture a parcel point becomes a line point when it sits on the boundary of an adjacent parcel but does not split the boundary line since point 32 sits on top of the southern line for parcel 1550 it is assigned a line point record that gets added to the line point table and associated with parcel 1550 let's go to this topics software demonstration here you can see that I'm in arcmap and the first thing you notice in my table of contents is that I have a series of layers I have a group layer that represents my feature classes utilities and easements I also have down here a layer that represents some raster data that represents my scanned images for original commercial records and right here you can see that we have the cadastral fabric player if I turn it off everything disappears from from the map I'm going to turn that on there is my only layer that is visible right now so everything that you see on the map is coming directly out of the cadastral fabric data set the Glacial fabric layer is actually a composite layer comprised of a number of different sub layers like control line points points lines and parcels these are all you saw all of these as fabric classes when I did the our catalog little demo what I'm going to do now is just do a quick identify on this parcel which is parcel 0 0 1 when I expand it it can get access to its lines seeing them highlighted on the map click there you'll notice right away that parcels have lines that define their boundaries of course but not only that they also have lines that extend out from the parcel and connect to things like control points these are connection lines another kind of line that you'll see are these radial lines that connect to the center point of the curve defined for this boundary if I open my magnifier window go over here and take a look in this location right here you can see that I have a control point called cp5 and here you can see it's coordinates when I expand it you can see that it is related back to the fabric point to 935 you can see that these two points have a connection defined within legit within the database within the Glacial fabric I'm not going to identify this line right here and in fact you'll see that it is two lines they are lines that overlap at this location this line is the southern boundary of this parcel highlighted and this line is the northern boundary of this parcel being highlighted right now you'll also notice that for this parcel over here there is a line that's connecting down and touching the line of the southern parcel and because of that there is a line point defined right there at this red circle so I'm going to click on that line point highlight it and take a look at the line point and see that it is a it is a line point for the southern parcel something else that I'd like to show you you'll notice here that we have all of these values showing up in red labels these are values that are coming directly like a dash of fabric from the lines from the records on these lines this 97 for example is connected directly or sorry matches exactly the record from the original record from the survey record on the subdivision plan over here again you can see that this 110 matches the 110 of the record and again this 8 in the record matches the 8 storm occur natural fabric the point to be made here is that you really need to make sure as best you can that the original record data from the survey record matches what is in the database if you want to achieve a spatial accuracy and tied in with control points but I'd also like to show you we turn on some feature classes here here I have some easements represented by green lines and some utility lines represented here in the blue I'm going to use my magnifier window and go zoom right into this area and you can see that this easement line the end of that easement line touches directly onto the Scudetto fabric line and we want to make sure that that spatial relationship remains intact as we move forward through this demonstration in this section we introduced the cadastral fabric you can think of the fabric as a connected boundary network or as a surface of connected parcels the primary goal of the fabric is to maintain the original cadastral record data and then also to use this data for improving a spatial accuracy of the cadastral layer this cadastral fabric can then be used as an accurate base map for the whole organization I'm going to hand over to Krishna he'll take your questions just faced him we have a question from Kevin and he's at MacDill Air Force Base and he asks our dimensions autogenerated for parcel polylines of polygons and to answer this question yes in the sense that if they don't have Colo attributes during the import we actually just inverse those dimensions Bruce from Juneau asks what about surveyed curves and we're actually we don't really talk about it too much and during the demo or the presentation but we do support curves and we do and we will also think about coming out and salmon fishing that was under one of your questions maybe Jean Ling from Arlington asks how was a Kadesh redditor different from the standard editor in arcgis ArcView and it's actually part of the serve analyst extension and it's a it was released for service pack 3 it's called the cadastral editor and we do have a set of tools that edit parcel specific to land records and we're going to talk about a more during the presentation bill from Nell's ville asks is this cadastral fabric new with the extension and yes it is and it's part of service pack 3 this when it was released Seattle asks can my cadastral data set reside in a version geo database and yes it can and we do support multi multi user editing okay and now we're back to Tim thanks Chris in this next topic we're going to talk about the different processes that we can use to enter new cadastral records into the cadastral fabric firstly existing parcel data can be imported from any format that supports the arc node topology structure of the oldest 7x coverage format we call data in this format cadastral fabric source data secondly data can be added incrementally into the cadastral fabric from individual original collateral record sources these original record sources could be hard copy plans or scan images in these cases the data can be entered manually using the bearings and distances for individual parcels as travis's or otherwise building multiple parcels from a set of construction lines the data could also come into the system as an electronic submission an electronic submission could take the form of a CAD file or could be an XML file name there are different techniques for bringing this data of these various electronic forms into the cadastral fabric most kadesha records in north america and also in other parts of the world like australia have historically been recorded and defined without any reference to coordinates in the sense each cadastral record is in its own local coordinate system in the cadastral editing environment you'll see that when you first enter data from the original record data you do so in a local coordinate space the user interface provides a blank map page and a blank spreadsheet grid into which you can enter the Travis data in this 0 0 coordinate space you will see the parcel lines being drawn in the zero zero coordinate space as the data is typed in this environment unjoined coordinate space we use the temp unjoined as opposed to joint space which refers to parcels and a projected coordinate system in a minute or so we'll talk about how parcels get from being unjoined to join but first I'm going to talk about construction lines in the cadastral editor you're not limited to entering parcels one at a time is unjoined parcels as you can see here and as you'll see in the demo also is that you can enter the paths of the parcels as construction lines this helps for example when you need to take advantage of lines that are tangent to each other or collinear and help save time because you do not need to re-enter the same bearings over and over again you can simply default to the bearing of your previous line that's one example of how construction lines are useful just like the M joint parcels the construction lines are also in the local zero zero Gordon space another very useful feature of the cadastral editors construction line environment is that you can also use pre-existing parcels as a template for your construction line work you can subdivide a parcel a parent parcel into child parcels you can create construction points on top of lines and then digitize to link up the points to create the construction lines the parcel the parent parcel remains intact and it continues to be stored in its original form in the Glacial fabric once you've defined these construction lines you can build new parcels from the construction lines parcels from the local unjoin space into the coordinate system of the cadastral fabric you need to join them the process of joining lets you define where the points of the unjoin parcels need to match the existing castles in the joined parcel space when you go through this process you get a report of the join residuals that include how well the data coming in matches the existing space that the parcel needs to fit into thing to understand about joining is that it is first and foremost a process for defining connectivity in the boundary network in other words it is about enforcing the topology and making sure the right points are connected this means that the shape of the high-accuracy parcel may be temporarily temporarily and should emphasize that temporarily distorted to fit the existing low accuracy parcels remember it's only the shape not the record that has changed here and this is to emphasize that you can note here that you're not changing the record value stored online table in this example even though the endpoints have had to be moved to make it fit into the existing commercial fabric the hundred-foot record value has not been changed in the lines table and the record for that line stays as the original value entered from the record source our goal is to now be able to use the connectivity defined by this accurate parcel along with its new record values on the lines to pour in the less accurate parcels to a more accurate position this process on the right is called the least-squares adjustment and we'll describe that in more detail on the final fourth topic but before we get there I need to talk about commercial XML with the release of the Collateral a deterent commercial fabric comes a new file format that can be used as a data exchange format the file is an XML file and it can be used to represent sub parts or portions of the collateral fabric in other words pieces of the fabric can be clipped out and stored separately in this file or on your hard disk these files might be used for backing up parts of the fabric used for an electronic submission format or used in supportive managing and audit trail of cadastral work orders or commercial jobs kadesha editor lets you easily export fossils into this new file of course since it's a data exchange format this file can then also be re imported into the commercial fabric house can be thought of as portable work orders for little portions of the fabric they can be considered cadastral jobs collateral jobs are actually a concept that exists within the commercial editor and there is a job's table that is part of the commercial fabric I've not talked about these yet but you will see them shortly in the demonstration the demonstration is really the best place to discuss jobs when bringing data into the fabric from a Kadesh or xml file it is referred to as a pending data since you are adding or a pending parcel data into the existing pre-existing potential fabric which usually already has some data in it here you can see what the text and the file looks like the structure of the XML file matches the data storage structure of the cadastral fabric in this demonstration I'm going to introduce you to the various user interface components that allow you to work and navigate with the data and add new data into the commercial fabric I'm going to do is add a new parcel into this area that will fit right at this location over here since we editing in a geodatabase first thing we need to do just click on the editor and say start editing on the standard editing toolbar now going to move this toolbar out of the view and here we have the cadastral editor toolbar I'm going to select the cadastral selection tool and select these two parcels and and pull them out into a commercial job to start work on them way I do that is to click modify on the selection and you'll notice two things happen or a few different things happen actually you get two new dialogues one is the parcel Explorer this is the parcel Explorer that you see right here and you also see parcel details in order to see the parcel details we need to select a parcel so I'm going to select parcel 29 and you can see the parcel properties in this property page and you and you can also see the lines of this parcel over here I can select parcels either in the map or in the parcel Explorer I'm going to select this second parcel here and you can see that I also have information about the MIS close on this parcel see in this case it's about one hundredth of a foot let us that these parcels are contained within a plan here you can see that we have a plan called 143 / 0 5 - so that plan is named by its book and page number that's in book 143 page 52 we're going to take a look at the properties of this plan you can see that I have information against I see the plan in here and I can also add information as a description such as being a portion etcetera the right record format is also available so this defines the record or the units and the manner in which the data is actually recorded on this plan of soft so I can see quadrant bearing degrees minutes seconds and units and other various of these other settings including for circular curves in order to add a new parcel I right-click on a plan and say new parcel you'll notice immediately that I have a parcel construction toolbar available to me and also have a local corner space a blank white page where I can start where I can see data coming into the local corner system and then also an integrate into which I can start entering record values I'm going to enter a very simple straightforward square parcel you'll notice that I can use simply that enter data using the rate keypad and I'm going to type in 45 degrees in the northeast quadrant being - one distance of 50 45 in the southeast quadrant 50 and as I go you'll see that lines getting added into the map on the right and now for my last line segment I'm going to intentionally add a little bit of a miss close 0 1 and close it back off and you'll see that I have a 0 1 miss goes represented here immediately as I indicated previously parcels done only necessarily have to be defined by their boundary perimeter boundary they can also have a lines that might connect out to control point or connect across the street to an adjacent parcel I'm not going to show you how you can add a new connection line here I'm going to click on this point 3 gets added to my grid I'm going to add a connection line 25 feet out from that point I'm going to change type 2 connection you can see it change color in the map and now that I'm happy with these changes I'm going to go and click keep this takes us back to the projected coordinate space and we can see once again in a parcel Explorer these two parcels that were originally there but now we also have this new parcel number 1 if I click on its properties you can see all the information that I've typed in here into there's the record but you'll notice of course that since we in a projected quota system we do not see the parcel in the space yet because it's an unjoined parcel we now need to go in and join this parcel into the fabric do that I'm just going to zoom in a little bit I'm going to right-click on this parcel let's say join when I do that the values for the lines of that parcel or the lines get added directly into the map and I can enter my existing map extent and I can then take it and manipulate it move it roughly into the position where I want it to go I want this parcel to fit into the space now you'll notice right away that it does that does not seem to match I have intentionally exaggerated the scenario here that occurs with typical data of this nature where adjacent surveys may be defined by different bases of bearing and a record line that's intended to go between the same two points or that there does represent ik that represents a distance between the same two points in the field may have different record values between due to different surveys so for the purpose of this demo I've simply exaggerated that scenario what I'm going to do is now join this parcel into the projected corner space so I click on the points on the joining parcel and then click on the fabric point and I'll do the same for this other point you'll see right away that I have a scale of two and a rotation of 326 not only can i connect points two points I can also connect this point to this line because I know this point belongs on that line this is going to create a line point it's not going to split this line for this puzzle it's simply going to put a line point at that location line point so important because when we do a least-squares adjustment and this parcel gets adjusted knees quarters get adjusted we want to make sure that this point this point stays on this line after these points have being adjusted and you can see here the line point is showing up as red I'm now going to go and finish this work finish the job and post it back into the cadastral fabric now you can see we are out of the commercial job and we're into the standard fabric view I'm going to identify this line right here this is the line for the New Castle that we've added and this is the line for the pre-existing parcel that was already there here's the record distance for each of these lines you can see that we have a hundred on this line and 50 on this line and that's of course because I intentionally made this this parcel I gave it a high scale factor but we know that this parcel is not very good and very accurate and we don't want this parcel to participate in any kind of adjustment we don't want the values we don't want this 50 to it to be attempting to define the distance between these two points so what we need to do is change the accuracy of that parcel in order to do that I'm going to go back to that same job in a way that I do that is I open my job book I find my job in the job book I right-click and I say open and this takes us back to the same view that we have before right when I finished the job so here I have my same job but now I want to change the accuracy of this parcel 1 so I can go and open as parcel now I'm notice when I open this parcel I go back into its local coordinate representation of exactly the way that I entered it so again these that what you're seeing here is being defined and drawn directly from the record the record that's defined over here but in this case what I want to do is simply change the accuracy on this parcel to be the lowest value which means that it won't participate in any adjustment once I've done that done that I can click to finish that work in the commercial fabric in the construction environment and then finish this job and post that change back into the casual fabric the next thing I'm going to do is show you how we would do a parcel split I'm going back into this area over here I'm going to zoom in a little bit and here's the area that we want it this is the parcel you want to subdivide you can subdivide it into five different parcels first thing I do select the area around this parcel go back again and say modify extract that parcel or extract that in those parcels into a good actual fabric job and this time I'm going to work directly from the map right click on the parcel and say new from pair I can get this context menu either from a selection in the map or from the parcel Explorer when I see when I do a new from pen what I see is that same similar view as before but with a few modifications here you can see rather than we then as having properties and lines in this parcel details view we have construction a construction set of lines that we can find construction lines for parent parcel is showing up in this local corner space as a template we're not able to change or adjust or do anything with the actual record values that we're going to use it as a template to create our new child parcels first thing I'm going to do is a break line on this original parcel I'm going to add record values of 68 at defined construction points along that northern line and do the same along the southern line and now I'm going to start matching these construction points in generating construction lines which you will see appear on your left right over here and these these are coming in directly from from the invest value between these two values now we may not necessarily like the inverse value in this particular case this very much this is very close to the actual record value but if for some reason this did not match the record we could go and change in is any of these numbers if I for example go and change this to something different 50 for example first thing you'll notice is that that does not affect anything to do with the connectivity between those two points and the other thing you'll notice is that this riff this record automatically gets highlighted because the system is detecting potentially something wrong with this number and it may be a mistake I could still go ahead and accept this but in this case I know that it is in fact the mistake so I'm going to change back to the true record value of 106 and now what I can do is click the build parcels come on so I can build parcels from this once I do that you can see that more familiar view of properties and lines for the parcel details and then I can go and select each of these parcels that have been created from that parent parcel once I'm happy with this I can finish this this work and the construction ramen and you can see that child parcels are now sitting on top of that original parent parcel I did not need to go to go through the process of joining again because we already had access we already knew where those parcels belong based on the current position I'm not going to go ahead and finish this job and check those changes back into the database back into the commercial fabric in the database in this topic we cover the concept of the unjoined space and the idea that you enter record data into a local coordinate environment I introduced the construction line editing environment that provides a bit more flexibility in data entry how to join parcels into the projected coordinate space and also I talked a little bit about the cadastral XML format I'll now turn it back over to Chris who will again be answering some of your questions thanks to him bill MJ and Richard have similar questions they're asking about documentation help and it's all with the latest release and service pack 3 so you'll have online help as well as the help in arcgis this asks earlier it was stated that a parcel record in the fabric can only be related to one record in the plans table is there another table or relationship to the tax map for instance one-to-many one parcel to many reference raster documents and in the data model we have those internal relationships and those are those are those are made but you can also have external relationships to say raster documents for instance so that's you can have that yes but uh in the actual data model itself there is a parcel to one plan so to add to that anything that you can do with existing feature classes is pretty much possible with fabric classes so if you wanted to create a relationship with an external table you could certainly do that from the fabric plazas thanks Shauna from Spokane asks can you build several parcels at once and from Tim's last part of his demo this is questions probably before that happened but yeah you can and Tim was showing how you can actually change record information as well if it didn't exactly match if you're just digitizing lines for one point to another Joon from Richmond asks how do you use cadastral editor and survey editor together and to answer that question you can use certain elements of the survey data set with the cadastral editor for instance the control points you can use those for your cadastral fabric and Rachel from Longmont asks how can you import CAD data into the cadastral fabric and we do have a couple ways of doing it the most common way that we've we found to do it is to add a DXF or I mean a CAD file to arcmap and actually borrow the geometry by just copying and then pasting that information into the construction grid and that way we're actually inversing the data that was on the CAD file but depending on how accurate the CAD file is it could be really close to record and so you can actually modify it slightly to make it work so that that's one way of doing it and we're going to go back to Tim thanks Chris now let's talk about our final topic improving spatial accuracy first of all I'm going to talk about accuracy and measurement systems generally in any measurement based system repeated observations provide system validation because they are used to double-check and triple-check the stored values one against the other multiple checks allow a system to identify mistakes that can then be removed by an operator by removing mistakes you can improve the overall accuracy of the whole system improving accuracy stems from repeated observations and the term used in measurement systems for this is redundancy now looking at the cadastral fabric it can be considered a measurement system with a record bearings and distances or credential boundary lines are the observations as we've seen these cadet will bow Nuri lines form a network that connect points together in this case for parcel 89 you see that with just a single parcel we simply have four lines that connect four points however once we add these other three parcels 1991 and 88 from potentially different record sources you can see that the number of lines goes up to 16 but that we now only have nine points so this this means that additional boundary lines define relatively fewer points and this is really the essence of what we mean when we talk about redundancy we add the final ingredient namely control points we have enough information to update the position of all the points in this network we're able to georeference parcel corners to the more accurate control point locations tests used to do this is called the least squares adjustment what does the least squares adjustment give us well firstly when all of the record measurements in control point coordinates are processed through this method we get a best fit estimate of the coordinate locations this means that if your data matches the original survey record and you have and you have accurate and valid control points that you can improve the coordinate locations of all the points not only there is tied to control the LSA process will also identify places riah ditional control points are needed the least squares adjustment process can identify lines with values that do not fit well with the rest of the information it's important to note that during the least squares adjustment process the original record values are not changed the control point coordinates are also not changed what has changed are the coordinates of all the regular fabric points the line work between these points are kept in sync with the changing positions of the points but the values on the lines themselves remain unaltered here's a view of the user interface for the least squares adjustment report these items highlighted in blue are the computed - observed values if you're familiar with the least squares terminology you may also know these as residuals these values are one way that the least squares report can indicate a problem in the record value or a mistake in the record value in this case you can see that we have a C - a value of one foot what this is telling us is that the corner computed between those two points defined or computed from the least-squares adjustment are out of sync with the actual value on the record by a foot reason that those coordinates were computed differently by that amount is that there was all this other information that allowed those corners to be computed other than just this one particular record so in a sense you can think of this line on this particular parcel as having being outvoted by all the other record information around this parcel a key element of the cadastral fabric is its function as a base map in many organizations we've seen a common pattern where the cadastral layer is maintained by a particular cadastral records department but it is used as a read-only spatial reference frame by other departments these other departments have a focus on other activities like maintaining services and infrastructure but they use the collateral layer as a spatial framework an accurate collateral base map can serve as a spatial control for the rest of the GIS The Adjustment vectors is a term that we use for the displacement between a points coordinates before and after a least-squares adjustment these adjustment vectors can be used to adjust other GIS layers in order to maintain spatial relationships to note here is that this is a different adjustment process an algorithm from the least squares however this G is featured justment process cannot happen without the data generated through the least squares in other words the GIS feature adjustment uses the results from the LSA and those results are of course these vectors these vectors get used by the GIS feature adjustment so I'm now going to go ahead and do the final demonstration for the support topic I'm going to go to a bookmark area I'm going to turn off my underlying imagery there going to select an area within the fabric that we all then go ahead and adjust again I go ahead and create a job extracting all of these parcels out of the fabric and creating a cadastral fabric job we don't need these dialogues parcel details and possibly explore us I'm going to shut those down so we can get a bit of a bit of a better view here the first thing we want to do with the least squares adjustment look at the control points I'm going to open up the control point dialog you can see here that we have a set of control points listed for example we have CP 3 and we have its coordinates easting/northing represented down here and we also have its let's point number the point that it is associated with the fabric point in the network when I do a check fit we can see how well the quadrants match each of the corners of the control points match with their underlying fabric points and over here you can see that we have about half a foot here of of mismatched this is and this is useful information for the next step which is to actually go ahead and do the least squares adjustment so I'm going to close this dialog I'm going to open up the adjust dialog and bring this down so you can take a look at this I'm going to accept most of the defaults here except for this particular one under the distances I'm going to change the check tolerances to three this will not affect the actual coordinate locations that get computed does this check tolerances set of dialogues or or options and values they're simply a way to filter out the results of the report that I get back after I click after I click the adjustment to off that click to go ahead and adjust so in other words any C minus F values or residuals that are equal to or higher than these values will get reported in my least squares adjustment report if any of the residuals are more than three times these values then as a safety measure the least-squares adjustment will not you we will not be able to accept the results of the least-squares adjustment now plan structure constraints will actually allow me to to make changes after the least bills adjustments has occurred in particular we want to be able to have line points match up and sync up with their with their lines so I'm going to click that checkbox and go ahead and click OK to proceed with the least-squares adjustment and bring that report down so you can see it now as you'll notice the adjustment completed successfully based on those parameters that I defined originally and you'll see that I have a bunch of other information here I have information about the number of control points used number of parcels number of corners and here you'll notice that we have none of bearings and distances at around 2600 but the number of corners is 822 so here is a very good example of redundancy we have this number of bearings and distances 2600 of each defining a roughly 800 corners and the number of knowns is an indicator of the level of redundancy we also see maximum shift of about 5 feet here at Point 808 we move further down in this report we'll see that we have some suspect points and lines so this is indicate an indication of certain lines that we should probably look at for possible mistakes and the record values based on the settings that I defined there was enough additional information another enough good information to maintain those coordinates within those check Torrance's that i defined so that's saying that I can so this is now I'm allowed to accept this new squares of justment if the adjustment had failed this accept button would not be enabled as a safety measure so I'm not going to go ahead and accept this new split adjustment and then I'm going to go in and finish the job as that's processing I'm going to talk of a little bit about what it's doing so everything that we extracted out of the commercial fabric all the points were recorded as the starting points of before the least-squares adjustment then now as I'm finishing the job and posting it back to the cadastral fabric the new positions of all of those points are also being recorded for each of the points so because we have those two points before and after for every single point we have an adjustment vector or a vector for every single one of the points in the database so now if we go back turn on our feature classes again open our magnifier and go take a look at what's happened first thing we look at we will notice that whereas before our points and our control points were at different locations after this least squares adjustment there are at identical locations so the points of the fabric have been moved into the positions of the corners of the control points the control point recordings have not been altered we go over and take a look at these utilities you can now see this blue line used to match up with this edge of this fabric boundary it no longer does sir and this was the one that we looked at before you can see here that this green line for the representing the easement feature class is no longer in sync with the boundary of the commercial fabric we want to be able to go in and correct this situation so I'm not going to use the future adjustment dialogue and add in this feature classes we can adjust them so I'm going to add them in and then also check them on to be adjusted and then I'm going to go ahead and click the adjust button now what this adjustment is doing is it's taking all of those vectors and using them to adjust the positions of these of these two layers so here you can see that now my easement feature class is now back in sync with the commercial fabric boundary and over here you can see that this utility line is back in sync with the Glacial fabric boundary if I don't like the results this was all done as a single headed operation so I can go ahead and undo those results if I do not agree with them or I can go ahead and redo those if in fact they were they were correct this is just also showing you the effect of this feature adjustment in this topic we saw that tip illogically connected parcels form a network of cadastral boundary lines using the information held on these lines along with the control points we can use a least-squares adjustment process to get best fit estimates for coordinates in the fabric and finally that these resulting position changes can be applied to other layers to keep them spatially up-to-date with a good astral fabric based map I'll not let Chris answer a few more of your question it's one of the state all the questions that are coming in or really good to Marjorie from Las Vegas asks are you able to use the plant information together with geo referencing or will using CAD data always copy paste and what I meant by copy paste was to actually take that geometry and paste it into the construction grid from there you actually have to build the parcels like Tim did for that new from parent and then you actually have to join it to the fabric so that could be that's similar to a geo referencing so that's how you get CAD data in bill from Milledgeville asks I looked at our catalogue and in my personal geodatabase I wanted to add a new casual fabric with the national Federer is grayed out why is this and a couple different it could be couple different things number one we require the survey analyst extension so if you don't have that you wouldn't be able to add a new cadastral fabric maybe the extension isn't enabled in the the options so that could be I'm sure that's that's what's going on MJ from bar Tao asks are there tools to aid in converting existing coverages to the cadastral fabric format and Tim mentioned it earlier in the presentation but we can actually import kogo coverages directly into the fabric or we and we do also have a data migration tool kit that will convert standard feature glasses to the fabric stores Larry from Tavares asks does cadastral editor allow you to create your own custom schema and we do have our own schema for the actual cadastral fabric data data set but you can customize this in any way Tim actually add an extended attribute to the to the data model you can have external relationship classes joins all that still available because it does act just like a standard feature class would Tom from st. Charles asked what happens to the parent parcel after the split and there's also other question here about tracking changes over time by Gary from Boise and what we do is actually flag this parcel as historic and so what you can do now is actually go to the properties of the fabric in arcmap and choose to view the fabric at different points in time so that all that information is retained in the database so the parent parcel is still kept in the database it's still all there all that information is there okay bill also has a question from Nellis Ville belt he asks I was a little confused about why the distance was 50 feet when he created a parcel but when he edited it measured 100 feet the distance changed 200 feet the legal said 50 right well what happened there was Tim was exaggerating a scale and rotation when he joined it to the fabric now anything that was entered in the construction environment or a new from parent environment is retained as a record value and that never changes so Tim could distort that parcel as much as he wants when he joins it in but those record that record informations always going to be preserved in lines and the other thing to note there is of course that 50 was grossly a gross exaggeration I was I was showing how you could make that could potentially have been an error for example and and I intentionally set that parcel to be to not participate in the v-square adjustment so that it wouldn't affect the positions of those points but if I left it in the least squares adjustment it would have been flagged as a problem and I would have been able to go and find that and then correct it to the correct correct value okay and that's that's all for the questions thanks Chris before we sign off I'd like to point point out some additional resources available to you we have a few courses coming up and you can find those at the at the website shown here at training DSR either come early 2008 we will also have a course called maintaining land records using the collateral editor that be one to look out for and we have some online resources you can go to the surveillance website shown here on your slide in front of you and there's also desktop help so that's all a freely available you don't necessarily have to have a license for this extension to find it you can simply go to that website and you'll see all the documentation for the software and we have some white papers so if for example you're interested in learning more about the least-squares adjustment is a mathematical model how does that all work we do have a white paper on that if you go if you go under support go to the knowledge base and find the white papers section you'll be able to find that information in a few weeks the recording of the seminar will be available for free on the ESRI virtual campus the resources listed on the slide and others will also be accessible from the recorded seminar we hope you enjoyed this seminar today on behalf of SR I I'd like to thank you all for attending

Channel: Mahmoud Abdelrahman

Views: 32,960

Rating: 4.9310346 out of 5

Keywords: Introduction, to, the, Cadastral, Editor, in, ArcGIS, Survey, Analyst, 9, 2

Id: zKRGnXwqESI

Length: 65min 31sec (3931 seconds)

Published: Mon May 02 2011