Optimization of Spatial Database for Enhancement of performance for Forward and Reverse Geocoding

Akansha Mishra

Geocoding And Geotagging

Introduction to Geocoding

Why we use Geocoding

Addressing System

Addressing System of different Countries

Different Geocoders

Levels of Geocoding

Geocoding Process

Reference Datasets

Geocoding Data

Spatial Database System

Optimization of Spatial Database

Spatial Indexing Algorithms

R-Tree and Quad Tree Indexing Algorithm

Challenges

Q & A

GEOTAGGING

Geocoding is the process of assigning latitude and longitude values to address information.

The process of getting Address data from Location data (lat/Long) is called Backward Geocoding.

Input Address: "642 Arbitrary Lane, Cityville, MA" or "Miami" or "FIPS county #64623“. Output Coordinates: "53.645 N, 73.6453 W"

GEOCODING

Geotagging is the process of adding geographical information to various media in the form of metadata.

Metadata consists of coordinates like latitudeand longitude, it may also include altitude, distance and place names.

Geotagging is most commonly used for photographs. It contains the information about where the photograph was taken.

Geocoding is the conversion of a human-readable location name into a machine-

processable location such as latitude and longitude.

Once a latitude and longitude coordinates is assigned the geocoded address can be

displayed on a map or used in geographic search.

Reverse Geocoding is the ability to find an associated textual location , like a street

address or business name from latitude and longitude coordinates.

Output:4383 Apple Ct Boulder CO 80301-1745-105.248599, 40.054337

Input:4383 Apple Boulder CO 80303

Geocoding

Reverse Geocoding

Geocoding allow operational spatial decisions to be made:

Where is the Customer? Nearest to which Cell Tower?

What is this point inside/close to?

What is the value/Risk/Danger?

Delivers Answers to Critical Business needs.

Facebook Check In:

Facebook Can use reverse geocoding to auto populate place address field during Check In.

Pictures, Status updates and other timeline events have location tags available.

Spatial ProcessingGeocodingBusiness Decision

An address is a collection of information that describes the location of buildings, apartment,

plot or other structure.

Address are two types:

Relative Address: Such As Across the Street, behind the landmark etc.

Absolute Address: Actual address that contain house no, street name, locality, town, state

and other address Components.

Components of address are house number/ Apartment number, Apartment Name, Street

number, Street Name, Zip Code and political boundary.

There is no globally applicable address format exist that works internationally.

Australia:[FLOOR] [/] [APARTMENT] HOUSE_NUMBER STREET_NAME STREET_TYPELOCALITY PROVINCE_ABBREVIATION POSTAL_CODEAUSTRALIA

Canada:[UNIT_NUMBER]-CIVIC_NUMBER [STREET_NUMBER] [STREET_TYPE] STREET_NAME [STREET_DIRECTION]LOCALITY PROVINCE_ABBREVIATION POSTAL_CODECANADA

Cameroon:STREET_NAME [HOUSE_NUMBER]LOCALITYCAMEROON

China:[BUILDING] [APARTMENT][HOUSE_NUMBER STREET,] [DOUBLE_DEPENDENT_LOCALITY,] [DEPENDENT_LOCALITY,] [LOCALITY]POSTAL_CODE PROVINCE

India:

[HOUSE_NUMBER] [STREET_NAME][DEPENDENT_LOCALITY] [, DOUBLE_DEPENDENT_LOCALITY]LOCALITY - POSTAL_CODEINDIA

United States:HOUSE_NUMBER STREET_NAME [STREET_TYPE] [STREET_DIRECTION] [BUILDING] [FLOOR] [APARTMENT]LOCALITY PROVINCE_ABBREVIATION POSTAL_CODEUNITED STATES

United Kingdom:[FLOOR] [APARTMENT][BUILDING][HOUSE_NUMBER] STREET_NAME [DEPENDENT_LOCALITY]LOCALITYPOSTAL_CODEUNITED KINGDOM

France:[APARTMENT] [BUILDING]HOUSE_NUMBER [STREET_TYPE] STREET_NAME [DEPENDENT_LOCALITY]POSTAL_CODE LOCALITYFRANCE

Turkey:STREET_NAME STREET TYPE [DEPENDENT_STREET STREET_TYPE] [BUILDING] [[No.] HOUSE_NUMBER [/APARTMENT]POSTAL_CODE [ADMINISTRATIVE_DISTRICT /] LOCALITY / PROVINCETURKEY

Google Maps

Yahoo Maps

Bing Maps

ArcGIS

Geocoder.us

MapMarker

Global Locator

Address Doctor

LOQATE

Zip Code Area

Street level Geocoding

----------------------------------------------------------------------

Point level Geocoding Address Point Interpolation

Zip+4 level Geocoding(6+4 Digits)

Zip Level Geocoding(6 Digits)Zip+4 Area

Point level geocoding:

• Address is matched to the location of the

Building Rooftop

GPS front Door

Parcel Centroid

• Point level geocoding is more accurate than Street level Geocoding.

Street Level Geocoding:

• Address is matched against a street segment address range.

Zip Code Level Geocoding:

• Zip code level geocoding returns the centroid of the passed Zip code area.

Zip+4 Code Level Geocoding:

• Zip+4 is the sub division of zip code.

Reference dataset provides the base data from which the geocoder

calculates, derives or obtains geocodes.

Linear Based Reference Datasets:

Roads and Ferries.

US Census Bureau TIGER provide vector line file.

Polygon Based Reference Datasets:

Administrative Boundaries and postal Codes.

Los angels Country Assessor Parcel Data is Vector Polygon File.

Point Based Reference Datasets:

POIs.

Australian Geocoded National Address File(GNAF) is Vector

Point File.

Most Geocoding Applications work with Vector

based GIS Data.

Vector Data represent features as:

Discrete Point

Line

Polygon

Vector Data is available in

TAB Files

Shape Files

Cad( AutoCAD DXF & DWG).

A database system that is used to store and query spatial objects:

Point: a hotel, a car

Line: a road segment

Polygon: landmarks

Spatial databases can perform a wide variety of spatial operations.

Optimizing spatial databases means

optimizing the queries, which requires less

time spent by running the queries before

receiving an answer.

Spatial Indexing is used to decrease the

number of searches.

Appropriate Indexes can reduce the Response

time.

Oracle Spatial uses two types of indexing: R-

Tree and Quad Tree.

R-Tree

Quad Tree

K-D Trees

K-D-B Trees

Grid Index

Z-order

Octree

UB-Tree

M-Tree

HTM

Geohashes

Objects(Point, Line and Polygon) are

grouped using the MBR(Minimum

Bounding Rectangle).

Objects are added to an MBR with an

INDEX .It index geometries in two or

more dimensions.

R-tree are more suitable for nearest

neighbor search.

Basic Spatial Operations are performed

much faster using an R-Tree indexing

types.

R1 R2

R3 R4 R5 R6 R7

R8 R9 R10 R11 R12 R13 R14 R15 R16 R17

R7

R6

R2

R1

R17

R16

R14

R15

R8 R1

0

R3

R9

R4

R5

R12

R13

R11

Desired Region

0 1

2 3

10 11

12 13132

Desired Region

133

130 131

It divides rectangular 2D regions into

quadrants until we reach at a desired

granularity.

Quad Tree Indexes are preferable when there

is heavy updates activity to the Spatial

Column.

It can easily integrate into traditional

database.

Quad Tree has its advantages in terms of

more complex type of Queries.

Spatial Data Layer

Primary Filter: Spatial Index

Data SelectionSecondary

Filter: Spatial Functions

Result

Optional Filter

Geocoding Accuracy: To correctly identify a

location.

International Geocoding :

Address formats vary

order of the address is often different

Use of Native languages.

Use of Multiple Data Sets.

Sequential Processing

Inconsistent use of base maps and geocoding

services.