Simplification of Parcel Mapping Process and its Application: Geographical Information System based Approach Dr. K.Ezhil Vendhan

©2010 CoreLogic, Inc. Private & Confidential 2 Launched from the First American Corporation, CoreLogic is a leading provider of consumer, financial and property information, Analytics and services to business and government We have more than 1 million users who rely on our data we have most comprehensive repository of public, contributory and proprietary data in the US like mortgage information, parcel and geospatial etc. We are working with over 40,000 clients in the public and private sectors WHO WE ARE

©2010 CoreLogic, Inc. Private & Confidential 3 Introduction A parcel map is perhaps the most convenient resource available to the public to determine the location and Parcel Identification Number of a property. Town officials like Assessors, Planners, Engineers, and others use parcel maps on a daily basis. So it is very important that parcel maps should show the current and updated information. History shows that most GIS implementation have some difficulties with parcel mapping process. In this perspective CoreLogic internally developed many customized GIS tools and various methods in AutoCAD Map and ArcGIS environment for parcel mapping, these methods plays vital role in creation of new parcel map and updating large quantity of existing parcel map.

©2010 CoreLogic, Inc. Private & Confidential 4 Basically these methods can be classified into three broad categories, I.Pre-Processing II.Production Process III.Final – Processing Aim The aim of this study is to analyze various methods of parcel mapping and simplification of the process to improve productivity and data accuracy. Processes

©2010 CoreLogic, Inc. Private & Confidential 5 1.Defined Folder Structure 2.Domain Controls in Data base 3.Pre- Defined columns 4.Clipping the county parcel based on available resources 5.Multiple file Re-projection tool 6.Add XY in Single field 7.Clipping stack and Non Stack Polygons Pre-Processing Methods

©2010 CoreLogic, Inc. Private & Confidential 6 Pre- Processing Methods Folder Creation Tool VB Script for Tool Creation 1.Defined Folder Structure

©2010 CoreLogic, Inc. Private & Confidential 7 Create Default Fields

©2010 CoreLogic, Inc. Private & Confidential 8 Create Domain Control Domain Control

©2010 CoreLogic, Inc. Private & Confidential 9 Clip Stack and Non Stack Line and PIN Clipped Polygon Clipped Stack Parcel Clipped Lines and PINs Clipping Stack and Non Stack Polygons

©2010 CoreLogic, Inc. Private & Confidential 10 Multiple File Geo Referencing This tool will be useful to Geo- Reference Multiple File

©2010 CoreLogic, Inc. Private & Confidential 11 Create XY Field in Single Field The XY creates in same field; it will be useful to find how may parcel have aligned

©2010 CoreLogic, Inc. Private & Confidential 12 Clipped Polygon Clipped Stack Parcel Clipped Lines and PINs Clipping Stack and Non Stack Polygons

©2010 CoreLogic, Inc. Private & Confidential 13 Parcel mapping Production process are classified under five major categories. 1.CAD conversion 2.Building parcel Raster to Vector (COGO and Georeference) 3.Maintenance Raster to Vector 4.Maintenance Spatial Alignment Process 5.Maintenance Existing data editing Production Process

©2010 CoreLogic, Inc. Private & Confidential 14 CAD Conversion Flow Chart

©2010 CoreLogic, Inc. Private & Confidential 15 COGO Method

©2010 CoreLogic, Inc. Private & Confidential 16 Geo-Referencing Method

©2010 CoreLogic, Inc. Private & Confidential 17 Maintenance Parcel – Raster to vector

©2010 CoreLogic, Inc. Private & Confidential 18 Maintenance Spatial Alignment

©2010 CoreLogic, Inc. Private & Confidential 19 Existing Data Editing Maintain Existing

©2010 CoreLogic, Inc. Private & Confidential 20 In Final process following methods are implemented for data accuracy. 1.Arc Google Synchronize tool 2.Multiple Stack Creation tool 3.Edge Matching 4.Multi Pin Check using Spatial Unique ID Creation 5.Spatial Join/ Forward Link 6.Non- spatial / Reverse Link 7.Summarize Check 8.Color Code Final Process

©2010 CoreLogic, Inc. Private & Confidential 21 Multi Stack Polygon Creation Tool Stack Layer Data Base

©2010 CoreLogic, Inc. Private & Confidential 22 OID Linking - Multiple Points Identification Line segment missing - Multiple Points Multiple points & Null polygons Polygon is created using the final Line and Point features. Spatial Join (OID linking / Third party tool) is done to check multiple point feature present in a closed line. All NULL and Multiple Points are corrected. Spatial Join is done to check whether all point features is converted to Polygon.

©2010 CoreLogic, Inc. Private & Confidential 23 Database Forward DB check / Spatial Join Common fields from the Spatial point feature and the Taxroll data are joined Unjoined DB are exported and verified the errors and it is rectified 23 Spatial Data Tax Roll data

©2010 CoreLogic, Inc. Private & Confidential 24 Non Spatial \Reverse DB Check Common fields from the Taxroll data and Spatial point feature are joined Unjoined DB are exported and verified the errors for rectification This Method is useful for identified Missing parcels and Stack parcel Spatial Data Tax Roll Data

©2010 CoreLogic, Inc. Private & Confidential 25 By summarizing APN and Map column an output of APN count is obtained for both Tax roll data and Map Data. The Map which has difference in APN count is checked again for errors. Summarize Check

©2010 CoreLogic, Inc. Private & Confidential 26 Color code (Symbology) District, Map and BLK are color coded and checked by panning, since dbase check will not clear all the errors

©2010 CoreLogic, Inc. Private & Confidential 27 CoreLogic captured 124 million parcels for 2,200 counties and townships Nationwide. CoreLogic ParcelPoint ® product enables users to access the highest level of positional accuracy for developing location-based solutions. Each Parcel’s Unique Identifier allows it to be linked to other forms of information, including Valuations, Service Areas, Environmental Factors, Demographics, and Parcel Data also enables sophisticated spatial analysis such as proximity, overlay and buffer zone operations. Parcel Mapping Applications in CoreLogic

©2010 CoreLogic, Inc. Private & Confidential 28 Integrating ParcelPoint product with flood risk zone is to provide more flexible and accurate decisions to the decision makers. Maintaining taxing jurisdiction data base for determining the valuation and classification for taxation of property. Parcel boundary data helps the homebuyer in identifying the best fit for new commercial development or matching their desirable location. Developing accurate models for locating fire response area could be the difference between life and death in emergency situation. Parcel data provides an efficient platform for utility companies like Power Management, Electricity, Gas, Telecommunications etc. Parcel boundary data is applicable to Insurance Applications

©2010 CoreLogic, Inc. Private & Confidential 29 Wireless communications companies which are using CoreLogic data as the underlying map for mobile advertising. Government agencies like United States Department of Agriculture (USDA) and FBI are using CoreLogic data for understanding Agriculture Trends and Crime Patterns. Insurance company State Farm is using parcel and natural hazard data to better determine insurance rates. These different industries have in common need to understand exactly where a property is on earth and the need to link the appropriate data to that location. Various industries relay on CoreLogic for accurate Geospatial Information

©2010 CoreLogic, Inc. Private & Confidential 30 Thank You