1. Department of Computer Science,
Remote Sensing & GIS
Dr. Kodge B. G.
Department of Computer Science,
S. V. I. T. M. Udgir (MS), India

2. Remote Sensing
Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth (both on the surface, and in the atmosphere and oceans) by means of propagated signals (e.g. electromagnetic radiation emitted from aircraft or satellites). The term RS was coined by Naval Research geographers of US in 1960s.

3. Remote Sensing

4. Remote Sensing There are two main types of remote sensing:
Passive remote sensing detect natural radiation that is emitted or reflected by the object or surrounding area being observed. Reflected sunlight is the most common source of radiation measured by passive sensors. Examples of passive remote sensors include film photography, infrared etc.
Active remote sensing emits energy in order to scan objects and areas whereupon a sensor then detects and measures the radiation that is reflected or backscattered from the target. RADAR and LiDAR are examples of active remote sensing where the time delay between emission and return is measured, establishing the location, height, speed and direction of an object.

5. RS & GIS Integration
The following terms may responsible for the success of any GIS application:
Geo-data acquisition
Data quality and resolution
Geo-reference and projections
Geo-data File formats
Software uses (front-end and back-end)
System requirements and designing
End user interface

6. Electromagnetic RS
Two characteristics of electromagnetic radiation are particularly important for understanding remote sensing. These are the wavelength and frequency. Wavelength and frequency are related by the following formula:

7. Electromagnetic RS E- Electric field, M- Magnetic Field and
C- speed of light

8. Imaging Characteristics of RS
The RS imaging system posses four major resolution characteristics.
Spatial resolution
The size of a pixel that is recorded in a raster image – typically pixels may correspond to square areas ranging in side length from 1 to 1,000 meters.
Spectral resolution
The wavelength width of the different frequency bands recorded – usually, this is related to the number of frequency bands recorded by the platform.

9. Imaging Characteristics of RS
Radiometric resolution
The number of different intensities of radiation the sensor is able to distinguish. Typically, this ranges from 8 to 14 bits, corresponding to 256 levels of the gray scale and up to 16,384 intensities of color, in each band.
Temporal resolution
The frequency of flyovers by the satellite or plane, and is only relevant in time-series studies or those requiring an averaged or mosaic image as in deforesting monitoring.

10. Extraction of metric information from remotely sensed images
Photogrammetry is used to obtain reliable measurements by means of photography. It uses computers and digital images to produce accurate topographic maps or orthoimages.
Non-Photographic RS System (Thermal infrared sensor, GPS, Reflected RADAR Signals).
Thematic Information (Image classification, LULC )

11. Integration of RS & GIS Separate but equal Seamless integration
Total integration

12. GIS Data Quality
The data quality refers to ‘fitness for use’ of data for intended applications.
Scope of geo-data quality (reliable, projected, relevant and current/updated).
Accuracy (roundup, inadequate survey )
Precision (exact single/double float points)
Errors ( gross, systematic & random errors)
Uncertainty (lack of data confidence)

13. Components of GIS data quality
The seven dimensions for GIS data quality:
Lineage (documentation of when, why data)
Positional accuracy (closeness of coordinates)
Attribute accuracy (descriptive closeness, TIN)
Logical consistency (real world model)
Completeness (final spatial & thematic data)
Temporal accuracy (world time & DB time)
Semantic accuracy (label with relational data)

14. Sources of Errors in GIS
Sources Inherent Operational
Map Projection Y N
Map Scale Y N
Field survey measurements Y Y
Image analysis Y Y
Sampling design Y Y
Digitizing Y Y
Raster to vector Y N
Overlay analysis Y N
Attribute data input Y Y

15. Finding & Modeling Errors
Checking for errors
Probably the simplest means of checking for data errors is by visual inspection.
Various statistical methods can be employed to help pinpoint potential errors.
Estimating degree of an error helps in controlling and correcting errors.

16. Internet Resources of GIS
The Internet contains a tremendous amount of information resources pertaining to the study and use of geographic data, Scientific papers on the concepts, techniques, and applications of GIS as well as information about hardware and software products.
Students are encouraged to take advantage of the power of search engines: Google, AltaVista, Yahoo.

17. GIS Information jump Stations
Where to start search
GIS Information jump Stations
(ESRI portal)
GeoCommunity (
(Minnesota Univ.)
(Nebraska linkon)

18. Pointers to Info. Resources
NASA EOS (
USGS-NIMA (egsc.usgs.gov/nimamaps)
NOAA (
USGS-SRTM (
OGISC (
NRSC-Bhuvan (
SOI (
NATMO (

19. Pointers to Data Resources
ESRI data online (
Alexandria project (
CIESIN (
ARKANSAS CAST (
GIS data depot (
DIVA-GIS (
Microsoft Terra server (
SRTM DEM (

20. Pointers to Product Info.
Computer manufacturer’s sites and
ERDAS Inc. (
ESRI (
Intergraph (
PCI Geomatics (
MapInfo (pbinsight.com/welcome/mapinfo)
Oracle Corp. (
Geoeye (

21. Internet based GIS applications
Google earth (
NASA world wind-worldwind.arc.nasa.gov
ARG GIS earth explorer (maps.esri.com)
NASA EOS (svs.gsfc.nasa.gov)
Indian ATLAS (atlas.gisserver.nic.in)
DST-NRDMS-NSDI (
VISA card ATM Locator-visa.via.infonow.net

22. GIS & RS Journals American Cartographer Cartography and GIS
IEEE T on Computers & Geosciences
Geometica
Int. Journal of Remote Sensing
Transactions in GIS
Int. journal of GIS
Journal of Remote Sensing of Envi.

23. Digital Terrain Model DEM, DSM and DTM.
A digital terrain model is a topographic model of the bare earth – terrain relief - that can be manipulated by computer programs. The data files contain the spatial elevation data of the terrain in a digital format which usually presented as a rectangular grid.

24. DTM

25. DTM

26. DTM
Mappers may prepare digital elevation models in a number of ways, but they frequently use remote sensing rather than direct survey data. One powerful technique for generating digital elevation models is interferometric synthetic aperture radar: two passes of a radar satellite (such as RADARSAT-1 orTerraSAR-X ) are used. DTM files formats like, DEM, DTED, HDT, Gird, xyz, dat, csv, etc. are available.

27. Approaches

28. Contours

29. TIN

30. DTM Acquisition Methods Accuracy Area Ground Survey VH Small
Photogrammetry H Large Engg Proj.
Cartography L Nation wide
Lidar/Radar H Wide
GPS H Medium

31. DTM Visualization ARC TIN & 3-D Analyst of ESRI
GeoTerrain of Bentley Systems
IMAGINE of ERDAS
MGE Terrain of Modular GIS software
Terraview
FLY of EASI Orthoengine
MATLAB of Mathworks
Global Mapper

32. DTM Applications Surveying & Mapping Hydrological & Geomorphological
Geoscientific
Engineering
Natural Resource Management
Military
National developments

33. GIS Implementation & Project Management
GIS Project Planning
GIS software evaluation and selection
Hardware consideration and acquisition
GIS Database design methodologies
Software Engineering in GIS
Software design methodologies
System Analysis & User Requirements

34. GIS Issues and Prospects
GIS Implementation (data, ownership, misusing, privacy, updating, documentation)
Technical issues (Evaluation, speed, memory and Management)
Integration with other applications.
Issues pertaining to people.

35. The Trend of GIS Development
Enterprise computing and GIS
Spatial data warehouses
Interoperability and Open GIS
National spatial data Infrastructure
Internet and its impact on GIS

36. Frontiers of GIS Research
Spatial data acquisition & Integration
Distributed computing
Extensions to Geographic representations
Scale
Spatial analysis in GIS environment
Future of spatial information
GIS and Society
Education and training.

37. Thank You..