Module - V

Integration of GIS and Remote Sensing

Analysis and Presentation

Integrating Remote Sensing & GIS

Michael Carmon

Integrating Remote Sensing & GIS

• Integration of RS and GIS creates a synergy in which the GIS improves the ability to extract data from remotely sensed data and remote sensing in turn keeps the GIS up-to-date with actual environmental conditions

Integrating Remote Sensing & GIS

• Most data available in digital form which are obtained from a wide array of sensors, data integration is a common method used for interpretation and analysis

• Remote sensing data integration fundamentally involves the combining of data from multiple resources in an effort to extract more information

Integrating Remote Sensing & GIS

• The remote sensing data are in multiplatform, multistage, multiscaled, multispectral, multitemporal, multiresolution, multiphase, multipolarized etc.

• By analyzing diverse data together, it is possible to extract better and more accurate information.

How data is extracted:

• Layers such as roads (yellow) and rivers (blue) can be easily seen from air/satellite photos

Multi-approach to Image Analysis

• Meaningful information should be extracted from imagery

• Ex: Detecting land cover change in an area is not enough because the final goal would be to analyze the cause of change or to evaluate the impact of change

• So, the result should be overlaid on map of transportation facilities and land-use zoning etc.

• Both RS and GIS data are in digital form and can be overlaid on each other and evaluated by modeling

Major uses of Remote sensing and GIS data in Integration

1. Use of classified data: Land cover maps classified from remote sensing data can be overlaid onto other geographic area data which enables analysis for environmental monitoring and its changes.

2. Use of ancillary data: Remote sensing data are classified or analyzed with other geographic data to obtain a higher accuracy of classification. They are sometimes used as maps with an overlay of political boundaries, roads, railways etc.

Multisensor, Multiplatform & Multiresolution images• When used multiple sensors the images are required to MERGE• Ex: When 2 sensors used – they differ in • Resolution• Pixel size• They may be of dift. Types • Required to merge data from • Dift. Platforms, • Dift. Sensors• Dift. Resolutions• Dift. Times, data can incompatible geometrically• Requires Geometric and radiometric corrections • Requires resampling or reduce distortions• Merging of high resolution images with low resolution images is very

popular

Multispectral Images

• Multispectral data are essential for creating color composites:

• Image classification• Indices/ ratioing • Principal components analysis• Image fusion• Dift. Wavelengths of incident energy affected

differently by each target and they are absorbed, reflected, transmitted in different proportions

Multispectral ImagesColor photos

Multispectral ImagesBlue filter

Multispectral ImagesGreen filter

Multispectral ImagesRed filter

Multitemporal/ Multiseasonal Images

• Information from multiple images taken over a period of time is referred as multitemporal information. Images taken over days, weeks, seasons, years apart

• Ex. Vegetable phenology: how the vegetation changes throughout the growing season

• Satellites are ideal for monitoring changes in the earth over time

• Ex. Mapping of growth of cities, population points, land use categories etc.

Japan before tsunami

Japan after tsunami

Japan before tsunami

Japan after tsunami

Multistage, Multiplatform, Multiscale and Multiresolution Images

Multistage, Multiplatform, Multiscale and Multiresolution Images

• Multistage remote sensing is used for landscape characterization that involves gathering and analyzing information at several geographic scales

• It includes complete coverage of target area with low resolution as well as high resolution imagery.

Multistage, Multiplatform, Multiscale and Multiresolution Images

• Multiscale images require a series of images at different scales, taken at the same time

• Multiscale images include images taken simultaneously by space-borne (satellite) as well as air borne images

• For interpreting multiscale images we use the larger-scale images to interpret smaller-scale images and vice versa

Multisource Data

• For this the data must be geometrically registered to a geographic co-ordinate system or map base

• So, all sort of data sources can be integrated together

• Ex: DEM and DTM model can be combined together with remote sensing data for a variety of purposes

• DEM/DTM are useful for image classification including slopes and terrains, also useful for 3D views and enhancing visualization

Q:Explain remote sensing and GIS synergy.

• The integration of remote sensing and GIS creates a synergy in which the GIS improves the ability to extract information from remotely sensed data and remote sensing in turn keeps the GIS up-to-date with actual environmental information

• In a digital environment, where all the data sources are geometrically co-ordinated, huge data can be extracted

• Any data source which can be referenced spatially can be used in this type environment. DEM(Digital Elevation Model) and DTM(Digital Terrain Model), digital maps of soil type, land-cover classes, forest species, road networks are such type of data source

Q:Explain remote sensing and GIS synergy(contd.)

• Example:• Remote sensing and GIS is being used in crop

management called ‘precision agriculture’• This help in monitoring and managing croplands,

predicting biomass or yields• The stages of precision agriculture are farm

management, crop needs, nutrients, pest/disease control, environmental contamination, crop species and variety selection, timing of field practices, conservation, soil organic matter, irrigation and minimizing erosion

Q:Explain remote sensing and GIS synergy(contd.)

• Map products derived from remote sensing are usually critical components of GIS.

• Remote sensing is an important technique to study both spatial and temporal phenomena.

• Large amounts of spatial data can be integrated and analyzed.

• This allow better understanding of environmental processes and better insight into the effect of human activities.

• Therefore GIS and remote sensing can complement and creates a good synergy

Presentation

• Satellite data are in the form of DNs. It is not possible to understand the contents by just looking through those numbers.

• It is required to extract relevant information from raw data and present this information in an easily understandable way. This technology is called visualization or visual data mining

• Processed remotely sensed data must be placed in to a format. The formats can be a print out , enhanced image, image map, thematic map, a spatial data base or graphs

GTU Question:Give the basic concepts how the damage assessment of agricultural crop will be interpreted using remotely sensed data and GIS software( page 119, Chandra)

• Remote sensing and GIS is being used in crop assessment called ‘precision agriculture’

• Condition of the crop is affected by supply of water and nutrients, insect and pest attack, disease out-break and weather conditions.

• By measuring physiological changes due to which the optical properties of leaves changes can be assessed by Remote Sensing techniques. The crop canopy geometry can also give substantial signals using remote sensing techniques.

GTU Question:Give the basic concepts how the damage assessment of agricultural crop will be interpreted using remotely sensed data and GIS software

• The task of crop condition assessment requires i. Detection of damaged crop,ii. Differentiation of diseased crop from normal

crop at a given time, iii. Quantification of extent and severity of the

disease in the cropiv. Assessment of production loss due to disease

GTU Question:Give the basic concepts how the damage assessment of agricultural crop will be interpreted using remotely sensed data and GIS software

• Crop condition is generally assessed on a grid-cell basis using multiband satellite data using remote sensing techniques.

• The area of interest is divided in to geographically referenced grid-cells of appropriate size and each grid is monitored individually.

• The flow diagram for damage assessment of crop is shown below. Vegetation Index (VI) for the pixels of crop is shown in another flow chart also.

GTU Question:Give the basic concepts how the damage assessment of agricultural crop will be interpreted using remotely sensed data and GIS software( contd.)

Rainfall Online Sensor data from Soil Sample | Cropland | | | | | Scanning and Screen Lab test results & | Digitization Actions required |---------------------------I ------------------------------I | Integration of RS and GIS based parameters using ArcGIS | Display of various Parameters, Maps, Results, Actions

Flow chart of Damage Assessment of Crop using RS and GIS software

GTU Question:Give the basic concepts how the damage assessment of agricultural crop will be interpreted using remotely sensed

data and GIS software( contd.)

Extraction of sample segment|

Generation of VI image |

Radiance normalization|

VI image for the crop|

VI profile using Multi date data Data base | | |

Condition of Crop----------------| Disease detection, Rainfall, temp.,Cloudy days, irrigated/Unirrigated

Flow chart of Damage Assessment of Crop using Remote Sensing Data

GTU Question:Give the basic concepts how the damage assessment of agricultural crop will be interpreted using remotely sensed data and GIS software( contd.)

• As shown in the flow chart effective assessment of agricultural crop can be interpreted by way of mapping, charts by integrating RS and GIS technology using ArcGIS software and data from Remote Sensing

Introduction to GIS Software

GTU Question:Write salient features of GIS tool GeoMedia or ArcMap

GIS software

• The term GIS software refers to a geographic information system application, which is software used to create, manage, analyze and display geospatial data on digital maps. GIS software is an increasingly specialized industry, with applications often specifically designed to meet the needs of certain industries

GIS software categories• Often it is distinguished between the following types of GIS

software• Desktop GIS are used to create, edit, manage, analyze and

display geographic data. They are sometimes classified into three functionality categories: GIS Editor, GIS Analyst and GIS Viewer.

• Spatial database management systems (Spatial DBMS) are used to store the data, but often also provide analysis and data manipulation functionality.

• WebMap Servers are used to distribute maps over the Internet (see also for the Open Geospatial Consortium standards: WFS and WMS).

• Server GIS provide basically the same functionality as desktop GIS but allow to access this functionality via networks (so-called geoprocessing).

GIS software categories• WebGIS Clients are used for data display and to access

analysis and query functionality from Server GIS over the internet or intranet. Usually One distinguishes between Thin and Thick client. Thin clients (e.g. a web browser used to display google maps) provide only display and query functionality while Thick clients (e.g. Google Earth or a Desktop GIS) provide often additional tools for data editing, analysis and display.

• Libraries and Extensions provide additional functionality that is not part of the basic GIS software because it may be not needed by the average user. Such additional functions can cover tools for terrain analysis (e.g. SEXTANTE), tools to read specific data formats (e.g. GDAL and OGR), or tools for the cartographic display of geographic data (e.g. PROJ4).

• Mobile GIS are used for data collection in the field.

Tasks accomplished with GIS software• Typical tasks carried out with GIS are:• Viewing / exploring data • Creating data (the dataset is extended) • Editing data (the dataset is modified) • Storing • conflation (integrating datasets from different sources) • transforming (into different coordinates systems, different

representations, re-sampling - resulting in new representation/format of the same data)

• querying (resulting in a selection from the dataset) • analysing (resulting in a new dataset, with new

information obtained from the original dataset) • create maps

GIS software

• ERDAS IMAGINE by ERDAS Inc; products include Leica Photogrammetry Suite, ERDAS ER Mapper, and ERDAS ECW JPEG SDK (ECW (file format))are used throughout the entire mapping community (GIS, Remote Sensing, Photogrammetry, and image compression).

• Esri – Products include ArcView 3.x, ArcGIS, ArcSDE, ArcIMS, ArcWeb services and ArcGIS Server.

• Intergraph – Products include G/Technology, GeoMedia, GeoMedia Professional, GeoMedia WebMap, and add-on products for industry sectors, as well as photogrammetry.

GIS Software

• How data are stored in ArcGIS• Components of ArcGIS – ArcMap, ArcCatalog

and ArcToolbox• GIS on the Web – ArcGIS Server, ArcGIS

Online, Google Earth.• Extensions of ArcGIS – spatial analyst,

geostatistical analyst and 3D analyst

ESRI GIS Development

Arc/Info (coverage model)

Versions 1-7 from 1980 – 1999

Arc Macro Language (AML)

ArcView (shapefile model)

Versions 1-3 from 1994 – 1999

Avenue scripting language

ArcGIS (geodatabase model)

Version 8.0, …, 9.3.1 from 2000 – Python scripting

160,000 licenses1,200,000 users as of 2009

GIS software packagesArc GIS

• The ArcGIS was produced by a Californian company called Environmental System Research Institute(ESRI)

• Arc-view is the entry level software of arc-GIS. The functions are provided for basic data entry, editing, attribute and coordinate manipulation functions. The basic spatial data analysis are supported with rapid and easy map layout and printing capabilities.

• Arc-editor provides the most commonly used spatial data manipulation functions. The complex editing tasks are carried out in Arc-editor. Some additional data management functions and the control over data base designs are also provided.

GIS software packagesArc GIS

• Arc-info is a comprehensive GIS software designed to provide a large set of geo-processing procedures, from data entry to digital data output. It is very sophisticated and complex product. It can support multiple data formats and all types of operations which are applicable to spatial data. To operate this software one should have in depth training.

• ArcGIS is a flexible software for data processing and has substantial analytical power. It is mostly used by geographers and many other GIS related scientists who want to store information to build a structure or models of the geographic features.

GIS software packagesArc GIS

• Three core data representations for vector data: coverage (ArcInfo), shapefile (ArcView) and geodatabase (ArcGIS).

• Relationships based on attributes (table fields) or on geometry (networks) are used to connect related geographic features

GIS software packagesArc GIS

• ArcGIS Components: ArcMap, ArcCatalog, ArcToolbox

• ArcGIS levels: ArcInfo, ArcEditor, ArcView• Desktop, Server and Web-based sources of

maps and data• Google Earth – web-based GIS and KML

addons

GIS software packagesArc GIS

• ArcGIS Extensions: Spatial Analyst, 3D Analyst, Geostatistical Analyst, Tracking Analyst

Arc Map

Create maps

Viewand edit data

Analyze data(Geoprocessing)

Arc Map

ArcMap (object editor)Powerful GUI for map creation and spatial data editingArcPlot/ArcEdit (from ArcInfo v. 7) & ArcView 3.2 View/Layout combinedMap projections on the fly (not via conversion as in AV)

GISC 6382 Applied GIS UT-Dallas Briggs

How to Project (and Define) Data:multiple different ways!

In ArcMap• Providing that it is already defined (projection

system known to ArcGIS), data brought into a data frame (whose coordinate system is also known) will be reprojected in memory to the coordinate system of the frame for display.– It can be exported in this (potentially) new

projection, if desired. • In effect, this “projects” the data.

–Note “double proviso:” known coordinate system for data inputted and for frame.

GISC 6382 Applied GIS UT-Dallas Briggs

How to Project (and Define) Data:multiple different ways!

In ArcToolbox• Generally, use tools in ArcToolbox to project data• Tools to DEFINE and PROJECT all data types are available• Coordinate system must be “defined” before running ProjectIn ArcCatalog• You can define the projections for shapefiles and coverages, but

you cannot generally reproject the original data without multiple steps.

• Providing that it is already defined, data brought into a new or existing geodatabase feature dataset will automatically be reprojected to the coordinate system of the feature dataset as it is saved there– It can be exported in this (potentially) new projection, if

desired. • In effect, this “projects” the data.

Arc Catalog

View data (like Windows Explorer)

Graphicalpreviews

Metadata

Tables

Arc Toolbox

Map Projections

Tools for commonly used tasks

GIS software packagesGeo-media

• The geo-media and other cartographic products have been developed and supported by Integraph Inc. Alabama, USA before some 35 years

• Geo-media provides the total set of data entry analysis and the output tools. A comprehensive set of editing can be attached to have automated data entry, error detection, data development, data fusion, complex analysis, data display, map making and scripting language. Data in any of the commercial databases may be integrated with spatial data from many formats

• It provides a comprehensive set of tools for the GIS analysis.

Remote Sensing software packagesERDAS

• Earth Resource Data Analysis System (ERDAS) was established as an image processing company.

• The original objective of the software was to enter and to analyze the satellite image data. After some time this company was able to bring out number of commercial products to collect and analyze the spatial data over an extensive area.

• This software also included other types of imagery and set of tools for cell-based data analysis. The image data is provided in a cell based format . It is easy and useful to develop these cell-based spatial analysis tools to help the image processing tools.

Remote Sensing software packagesERDAS(contd.)

• The ERDAS and other image processing packages provide the data output format. They are compatible with most of the GIS packages. The support ESRI format gets, is from ERDAS. To analyze these spatial data the ERDAS GIS components can be used.

GTU Q : Remote Sensing software packagesENVI with its features

• ENVI (which is an acronym for "ENvironment for Visualizing Images") is a software application currently marketed by ITT Visual Information Solutions used to process and analyze geospatial imagery. It is commonly used by remote sensing professionals, scientists, researchers, and image analysts.

• ENVI software bundles together a number of scientific algorithms for image processing a lot of which are contained in automated, wizard-based approach that walks users through complex tasks.

Remote Sensing software packagesENVI

• ENVI was originally developed by adapting the U. S. Geological Survey's REMAPP-PC public domain DOS-based image processing package, then extending that adaptation through extensive enhancements. ENVI was subsequently sold to Kodak. A brief mention of such development is here.

ENVI salient features

• Automated workflow tools – SPEAR Tools• ENVI improves the image processing workflow with

functionality that allows image analysts to perform basic and advanced image processing routines easily and quickly. This ENVI release introduces SPEAR Tools.These tools include automated processes for spatial and temporal change detection, pan-sharpening images, terrain categorization, and more.

ENVI salient features

• Advanced image processing capabilities Vegetation Suppression :

• The Vegetation Suppression feature allows image analysts to visually remove vegetation from an image in order to see what is concealed by the vegetation, such as geologic and urban features and vehicles or other objects of interest.

ENVI salient features

• ENVI Feature Extraction (ENVI Fx)

• The ENVI Feature Extraction Module (ENVI Fx) allows to quickly and easily extract features from high-resolution imagery.

• Rapid preview screens allow for adjustments at any point in the workflow. ENVI Fx is built with a high performance image processing engine to deliver fast results, even with large datasets

ENVI salient features

• ENVI Orthorectification Module

• The ENVI Orthorectification Module gives an orthorectification method and robust capabilities, all distilled into and easy-to-use workflow. When compared with simple geometric registration, ENVI’s rigorous method is far more accurate and essential to applications where precision matters, such as engineering roadways or bridges, or targeting specific objects of interest.

ENVI salient features

• IDL

• IDL is a solution for data analysis, data visualization, and software application development. From “quick-look” analysis and display to commercial programming projects, IDL combines the technology and tools.

ENVI salient features

• Image Access Solutions (IAS)

• IAS is rapid image delivery technology that gives real-time access to the geospatial imagery needed for critical decision making.