SURVEY TRAINING INSTITUTE
CADASTRAL SURVEY
GEOSPATIAL INTEROPERABILITY
AND WEB ENABLED GIS
by
B.N.Dash
Superintending Surveyor
CADASTRAL SURVEY
Historical Background:
The Moghul revenue administration demanded precise
measurement of productive cultivated land.
They used llahi Gaz a measure of length which was
divided into 24 equal parts and each was called tussuz.
However ,there was a variation of Gaz in Moghal India.
The Bigha was a land of 60*60 Gaz.The larger unit
was the Kos each consisting of 50 llahi Gaz or 400 poles.
Each pole was of length 12.5 Gaz.Thus Kos was a
length of 5000 Gaz.
During Chola period in Tamilnadu, the
smallest unit used was a Viral(finger) 12virals
makes a chain, 24virals makes a muzham(cubit).
Muzhakot was a 9 ft or 12 ft long used as
measuring rod.The smallest land plot was 12 ft
square called KUZHI.
Hundred Kuzhi make a Kaani.Five Kannis
was VELI.
Similarly in Western India there was a
different system of measurement for assessing
the tax.
British used Distance & Angular
measurement for route map.
In India the Triangulation by George
Everest could make a better accurate map.
But the states of India have different
procedures for making maps and till now
the whole India has not been brought into
one system.
VARIOUS PROCEDURE TILL NOW ADOPTED:
• Plane table traverse
• Theodolite Traverse(Angle by Vernior Theodolite)
• Rectification of Photographs
• Photogrammetry from Large scale photographs
• Digital photogrammetry using photos
• Digital photogrammetry using Satellite Imagery
• Coordinate based through total station
• Coordinate based through GPS
Different Scales of Cadastral Map
F.P.S
System
Metric
System
Purpose
16 " to 1 Mile
1:4,000
For Cultivated Fields
32 " to 1 Mile
1:2,000
64 " to 1 Mile
1:1,000
For smaller field plots
small towns ,costly
lands
For towns and cities
128" to 1 Mile
1:500
For very large cities
REQUIREMENT OF HARDWARE:
 PENTIUM 4
 SCANNER A0 SIZE
 PLOTTER A0 SIZE
 INKJET PRINTER A4 SIZE
REQUIREMENT OF SOFTWARE:
CAD SOFTWARE LIKE AUTOCAD/MICROTATION
EDGE ADJUSTMENT SOFTWARE
PROJECTION MAKING SOFTWARE
ARCINFO/GRAM++/GEOMEDIA FOR LIS/GIS
INDIGENOUS SOFTWARES FOR PLOTMAPS
INDIGENOUS SOFTWARES TO MEET SPECIFIC
REQUIREMENTS
The Land information system is a
Government integrated infrastructure delivery
system to facilitate the user urban and Rural
people and to the Government officials for
smart decision making.
 In this scenario the Central and State government should
come forward to make an integrated system.
 The government of India and the state governments
should come forward to have a land information system.
 It is also required to change the old policy framework
which coordinates the collection, display, access to Land
information system.
 At the end the integrated system can be put in the web
for easy accessing.
 Inaccurate
 Finding out area is a raw procedure
 Procedure followed inaccurate (Plane table traverse,
Vernier theodolite).
 Adjustments not done between starts and ends
 Error thrown to government areas like
(Forest areas / Waste land)
 Updation is difficult
 Apparatus used were very inaccurate
 Adjustments by Amins (in the hands of
under matriculate people)
 Play/Adjustment can be made with
divider by amins
 More litigations arose in Rural area than
Urban area
 Cannot be printed to any scale
 More and more inadvantageous
 Decision
making easier
 Litigacy solved easily
 Can print the map to any scale
 By digitisation linking can be
made for Land information system
 Accuracy maintained
 Quick updation
Digitisation is a must to bring into computer.
• Photograph (Aerial) and digitize
• Imagery and digitize
• From Ortho Photograph
• Total station and simultaneous digitize
• GPS and digitize
• Any other coordinate system and make a database
For built up area all care should be taken to
pick up the base.
In case of Field data observations, directly the
coordinates are brought into computer. The spatial
information is thus generated.
The imagery is brought to ground system by
Georeferencing whereas photographs are brought
into ground system by suitable orientations and
IMT (Independent ModelTriangulation)
Attribute data can be collected from the Tahsil
Office or so and can be linked to the existing spatial
data for Query and Analysis.
Imagery /
Photographs : The area covered by trees, water & shadow
is a problem which should be again
collected by sending the field hands to
field by Field measurement observation
(through optical square/Total Station/GPS).
Built up area : Here the cost is high. All care should be
taken to capture the coordinates by
ground method.
Ground truth : The owner does have belief with his old
area and does not accept the change in
area in any form though his land binding
is intact.
However, it has been proved with 0.5 metre accuracy
established from the photograph (10,000 scale)
and correction / insertion / deletion made by field
measurement observation.
The survey from imagery (IKONOS & QUICKBIRD)
will give correct result if the georeferencing is made with
short interval and feet that one data of QUICKBIRD may
be divided in A4 size of data and made the referencing.
Total station & GPS:
The procedure is very accurate but time taking.
The observer has to make a separate sketch for
making & drawing of plots
The area which are inaccessible are difficult to
capture
The area which are prone to Naxalites & Maoist is
further difficult to collect data from field
The most difficult is outturn .
However it is advantageous to have GIS attributes
simultaneously.
 Change of course of the river
 Government plots like roads, waste land area may be
more or less which is not be acceptable to Govt.
heads.
 Survey of village boundary are not shown/destroyed
 Old policy a bottle neck
 Some imaginary line drawn for dividing plots not
traceable on ground
 To incorporate the missing details arose by
Photogrammetry / Imagery
 Outurns
 Manpower
 Educating in current system
 To have the plot No.s serpentile manner (Now solved
by a look up table)
 Division of plots by owner, share holders after making
the map (Last No. of the plots can be given)
 Bigger plots appearing in two sheets (Imaginary line
is drawn at the division)
 To make map in regional language (overcome by linking
the Leap office engine)
 Preparing plotwise map to get dimensions, so that
correct decision can be taken for encroachments
 Updation by field measurement using Total
station.Updation by Optical square(Only for plane
Area),only applicable where Height difference is
within 2 metres
 Transformation within known coordinates
 Merging of updated Data in main DAtabases
 Updation based on measurement taken from field
Division of Plots based on length on the sides
 Simultaneous updation of Edge and Adjacency is
required
INTEROPERABILITY AND WEB
GIS
Interoperability and constraints:
• Organisations maintain and provide specialised data
according to their functions
• Users or even organisations themselves need other datasets
for a particular application.
• The data integration between different systems is not
straight forward
• Proprietary data formats are a major obstruction for data
integration.
• The addition and integration of data into existing databases
gives many problems
•Sharing is next to impossible
•Diverse data format
•Different storage mechanism
•Different spatial reference system
•Difficult in overlaying
•Principle/Policy binding
•Flat file/relational/Hierarchical
•Access is difficult
•No metadata file to keep track
•May or may not be up to date
•Legality of using data and fixing responsibility
REQUIREMENT OF INTEROPERABILITY:
Though constraints we must share data to avoid
repetition and cost effective for which:
Converting data into common standard platform
To define a standard accessing
Flexibility in adding data
There should be heterogeneous need accessibility
Proper metada with specification and details
DIFFERENT SPATIAL DATA CREATION:
Vector Data Format
From Microstation
From Autocad
From Erdas
From Mapinfo
From Geomedia
From Geoconcept
From Gram++
Vector product format vpf
Raster Data Format:
Bmp
Bsm
Cal
Gif
Hrf
Igs
Rle
Cot
Rgb
Jpg/Jpeg
Tif
Database Format:
Dbf
Mid
Mdb
Plane Text Format
Txt
Ps
Pdf
……………………….more and more
Open GIS?
The Open GIS Consortium (OGC) is "an international,
member-driven, non-profit industry consortium of 258
companies, government agencies and universities participating
in a consensus process to develop publicly available interface
specifications and geoprocessing interoperability computing
standards.
 OGC supports interoperable solutions that 'geo-enable' the
Web, wireless and location-based services, and mainstream IT.
The specifications empower technology developers to make
complex spatial information and services accessible and useful
with all kinds of applications
Close relation with ISO(International Organization for
Standardization)
GML ?Geography Markup Language (GML)
•Wide scope of work in a broad geospatial
marketplace that includes not only geographic
information systems (GIS), but also mapping,
earth imaging, sensor webs, and mobile wireless
services.
• It also highlights the importance of OGC Web
services standards as part of information
technology best practices for integrating
geospatial processing into service oriented
architectures and enterprise workflows.
•A set of XML technologies for spatial data
Advantages of GML:
•GML is easy to understand
•GML data can be mixed with Non spatial Data
•GML data can be mixed with imagery and video data
•GML is open and user friendly
•GML also supports to WEB servers,annotation,map own
designing and spatial analysis
•GML also readable
•Defines XML-Schema, XML grammar for the encoding of
geographic information including geographic features, coverages,
observations, topology, geometry, coordinate reference systems,
units of measure, time, and value objects
Application of GML:
•Internet Mapping
•Disaster Management
•Accident and Police Investigation
•Emergency Service
•Internet GIS and GIS portals
•Muncipal and Government Services
•Land Information system
•Wireless Service
•Graphical drawing both 2D and 3D
•Semantic Data(Meta data & Relation ship)
•Transformation(Spatial & Non Spatial)
XML?(eXtensible Markup Language):
XML is eXtensible Markup Language, the new-generation
Web technology for representation and transmission of
structured data over the Web
XML is a newly approved standard for Web documents.
XML can be seen either as a big improvement over HTML
(the current Web page language), or a simplified version of
SGML (Standard Generalized Markup Language), ISO 8879
by the International Standards Organization(ISO)
XML is ideal for developing Web presentation and
transmission techniques for geotechnical data because of the
extensibility and other features of XML. XML has its own
style language, XSL (eXtensible Style Language).
The XML to be used for web GIS:
 If the data is in XML format, then I can access
it from any operating system, as well as format it
to any format, be that format another XML
structure, PDF, Word documents, or HTML.
 XML is also useful in isolating your content
from formatting. For instance, you could easily
create the content an entire Web site in XML
documents and then transformed using XSL
Transformations (XSLT) into HTML.
WFS?(Web Feature Service);
The OpenGIS Web Feature Service (WFS) Implementation
Specification allows a client to retrieve and update geospatial
data encoded in Geography Markup Language (GML) from
multiple Web Feature Services.
Operation should be available in WFS:
- Create feature
-Delete feature
-Update Feature
-Lock Feature
-Transaction feature
-Get or query features based on spatial and
constraints
non-spatial
OGC Web Feature Server Interfaces model
Mandatory
GetCapabilities
DesribeFeatureType
GetFeature
Optional
Transaction
LockFeature/GetFeturewithLock
Update,Delete,Insert
Two classes of WFS:
Basic WFS: This gets the feature,desribe the
feature type.This is READ ONLY Web Feature
Service .
Transaction WFS:
This is the Web Feature Service which
supports all the operation of a basic web features and also
implement the transaction operation .The transaction WFS
also does operation like create,update and delete operations on
geographic features
LockFeature/GetFetureWithLock: WFS may be able to
process a lock request on one or more instances of a feature
type for the duration of transaction
When writing a WFS , we must implement the
operations like:
GetCapabilities - this queries the WFS service to determine
available options.It must indicates which feature types it can
service and what operations are supported on each feature
type
DescribeFeatureType - this retrieves the XML schema to
allow the WFS client to parse the result sets to describe the
structure.
GetFeature - This performs the actual query - parameters
such as bounding box with cartesian coordinates and any
other filters should be passed in, as appropriate, and the WFS
service then returns a GML result set containing full
geometry and feature attributes.
WMS?(Web Map Service):
Web Map Service (WMS) produces maps of spatially
referenced data dynamically from geographic information.
This international standard defines a "map" to be a portrayal of
geographic information as a digital image file suitable for
display on a computer screen. A map is not the data itself.
WMS-produced maps are generally available in a pictorial
format such as PNG,GIF or JPEG or occasionally as vectorbased graphical elements in Scalable Vector Graphics (SVG)
WMS clients:
•Googlie Earth
•NASA satellite Imagery/Photographs
•gvSIG,Openlayers,Qgis
WMS Server:
•Map Server
•Geoserver
•ArcIMS Server
•ArcGIS Server
•Oracle Mapviwer
Web Map Service operations can be invoked using a standard
web browser by submitting requests in the form of Uniform
Resource Locators (URL).This shows what portion of the earth
is to be mapped, the desired coordinate reference system, and
the output image width and height.
OGC Web Map Service Interfaces:
GetCapabilities
GetMap
GetFeatureInfo
GetCapabilities Interface:
•Provides information about what a server can do ,what
data layers it can serve,formats available
•Response encoded in XML
GetMap Interface:
•Required map Service Interface
•Provides clients of a Map Server with
picture of maps
•Key Parameters
-layers
-Styles
-Box
-Format
GetFeatureInfo Interface:
•Optional Interface
•Asks for information about features display in the map
•Response is free from html
Example of Request for GetMap:
Http://b-maps.com/map.cgi?version1.1.0&
Request=GetMap&
SRS=EPSG:4326&
BBOX=100.102,25.523,87.894,34.897&
Width=560&
Height=350&
Layers=sea,house,school&
Styles=0xff8080,0x101040,black&
Format=image/png&
Bgcolor=0xffffff&Transparent=True&
SLD?(Styled Layer Descripor):
 This document explains how the Web Map Server specification
can be extended to allow user-defined symbolization of feature and
coverage data. It should be read in conjunction with the latest
version WMS specification.
 Symbolization to map data
Styling
Addresses symbolisation within current and past OGC service
Cartographic Design of GeoData
Can Custom the style WMs content
Can Custom the style WFS content
Style Layer Descriptor Enabled Web Map Service
Syntax :
<StyledLayerDescriptor version="1.0.0">
<NamedLayer> <Name>WorldGen_Outline</Name>
<UserStyle> <Title>xxx</Title>
<FeatureTypeStyle> <Rule> <LineSymbolizer> <Geometry>
<PropertyName>center-line</PropertyName> </Geometry>
<Stroke> <CssParameter name="stroke">#0000ff</CssParameter>
</Stroke>
</LineSymbolizer> </Rule> </FeatureTypeStyle> </UserStyle>
</NamedLayer> </StyledLayerDescriptor>
Symbols:
Linestring,Polygon,Point,Text,Raster
<Strroke>Color,opacity,width,join&cap,dash pattern
<graphic>
<fill>color ,opacity</graphic>
<graphic>external URL,”mark”,size,rotation
<text>font,label placement,’”hai”,fill
<Raster>opacity,channel selection,overlap,colormap,contrast enhance
<filter> <expression>
Style Layer Descriptor (SLD)enabled
Web Map Service(WMS):
SLD and WMS adds the ability to control layer style
SLD and WMS facilitates
-DescribeLayer
-Getlegendgraphic
-Getstyles
-Putstyles
WMS layer can be symbolized if they originate from a
feature source
WCS?(WEB Coverage Service):
•WCS provides available data together with their detailed
description.
•WCS also allows queries against the data and returns data
with original semantics(instead of pictures) which can be
interpreted
•The basic Web Coverage Service allows querying and
retrieval of coverages.
•WCS describes discovery, query, data transformation
operations. The client generates the request and posts it to a
web feature server using HTTP. The web feature server then
executes the request. The WCS specification uses HTTP as the
distributed computing platform.
•Supports many formats and encoding
•WCS is not so much operational as WFS
•Metadata are complex
•As coverage is a Mathematical function a mapping from
geographic domain space to range space is a typical measurement
•This supports data format like:
-Series of points, such as locations of samples
-Regular grid of pixels or points
-Set of segmented curves, often used for road paths
-Triangulated irregular network(TIN), often used for DEM
- Ranges of information may be attached to locations, such as
average wind speed or yield by crop type.
DISPLAY OF GML DATA
[SVG?(Scalable Vector Graphic)]
•AW3C (World Wide Web Consortium)standard format
•Works directly with Web browser
•Requires a SVG plug-in(free from Adobe or other
vendors)
•XML specification and File Format for describing twodimensional Vector Graphic, both static and animated.
SVG can be purely declarative or may include scripting.
Images can contain hyperlinks using outbound simple
Links.
ADVANTAGES OF SVG:
•Vector graphics NOT Raster image formats JPEG,GIF,PNG
etc
•Supports Vector,Raster and Text
•Can be displayed in any scale
•Can be even displayd in cell phone
•SVG can grow to many files ,many users and wide variety of
use on WEB
•SVG also reduces size of image by allowing comlex scalable
graphics
•SVG file is a XML file so allows portability
•SVG file can be edited and displayed in any environment
regardless of computer operating system and Web browser
•SVG is an XML files so hyperlink is possible to raster and
vector both
•SVG drawings can be dynamic and interactive.
•Time-based modifications to the elements can be described in
SMIL or can be programmed in a scripting language (e.g.,
ECMA script). The W3C explicitly recommends SMIL as the
standard for animation in SVG.
•SVG is an application of XML . SVG file is therefore a
simple TEX FILE which can be viewed and edited as with any
other markup Language file.
An Example of SVG:
<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="467" height="462">
<!-- This is for the red square -->
<rect x="80" y="60" width="250" height="250" rx="20" fill="red" stroke="black"
stroke-width="2px" />
<!-- This is for the blue square -->
<rect x="140" y="120" width="250" height="250" rx="40" fill="blue" fillopacity="0.7" stroke="black" stroke-width="2px" /> </svg>
XSLT?(Extensible Stylesheet Language
Transformations):
•XSLT developed by W3C for applying data to XML in formatted
way
•The language used is XSL for expressing style sheet
•Style sheet are used to desribe how the contents of a given
structured document should be presented
•By this the source content is styled laid out on to some medium
such as window in a WEB browser or hand held device
•XSLT are ideal for processing because both GML and SVG are
XML standards
•XSLT enables and empowers interoperability