This document discusses data collection methods for spatial and non-spatial data. It describes different types of data like raster, vector, and attribute data. Methods of data collection include land surveying techniques like chain surveying and using total stations, as well as remote sensing using aerial photography and satellite imagery. Common data sources are provided by organizations like the Survey of India and ISRO. The document also covers topics like digitization in GIS and using software like AutoCAD.

1. DATA COLLECTION
by
Dr. Rambabu Palaka,
Associate Professor
Dept. of Civil Engineering
B.V. RAJU INSTITUTE OF TECHNOLOGY
July 2016

2. DATA
1. Spatial Data
Data that define a location. It includes location, shape, size and
orientation. Often this is done with x, y coordinates or longitudes
and latitudes. These are in the form of
a) Points - Valves
b) Lines - Pipeline
c) Polygon - Water Tank
d) Pixels - Satellite Image, Aerial Photograph
2. Non-Spatial Data or Attribute Data
Data that relate to a specific location.
Ex.: Water Tank Capacity, Pipe Type, Pipe Size etc.,

3. Different ways of Data Collection
Land Surveying
 Chain Surveying
 Compass Surveying
 Plane Table Surveying
 Leveling with Auto Level, Theodolite
 Tachometric Surveying
 Trigonometric Leveling
Advanced Land Surveying (Vector Data)
 Total Station
 GPS, DGPS, GPS RTK
Remote Sensing (Raster Data)
 Aerial Photography, LiDAR
 Remote Sensing – Satellite Images

4. DATA TYPES
1. RASTER
Raster data is made up of pixels (also referred to as grid cells).
In raster, each pixel is associated with a value or class.
Ex.: Each pixel value in a digital aerial photograph is associated
with a red, green and blue value.
2. VECTOR
Vector data is not made up of a grid of pixels. Instead, vector
graphics are comprised of vertices and paths.
The three basic symbol types for vector data are points, lines
and polygons.
Ex.: AutoCAD Drawing

7. Different Sources of Spatial Data
1. Surveying of India (Hard Copy & Soft Copy)
a) Village Maps
b) TopoSheets
2. Nationa Remote Sensing Center (NRSC)
a) Satellite Data
b) Aerial Photographic Data
c) Thematic Layers (Vector Data)
3. ISRO Bhuvan Website
a) Satellite Data
b) Thematic Layers (Vector Data)
4. Google Maps or Google Earth Pro

8. Remote Sensing
Remote Sensing is the acquisition of
information about an object or
phenomenon without making physical
contact with the object and thus in
contrast to on site observation.

9. Remote Sensing
Device to sample and measure radiation
Medium = electromagnetic radiation
Target is the terrestrial environment
(atmosphere, oceans, land surface)

10. Remote Sensing

11. Device to sample and measure radiation (sensor)
LISS – III Camera
(Linear Imaging Self Scanning Sensor )

13. Aerial Photograph

14. Satellite Image

16. Digitization
Digitization in GIS is the process of converting
geographic data either from a hardcopy or a
scanned image into vector data by tracing the
features.
During the digitizing process, features from the
traced map or image are captured as coordinates
in either point, line, or polygon format.
Software:
Google Earth Pro, AutoCAD, ArcGIS etc.,

18. AutoCAD
AutoCAD is a CAD (Computer Aided Design or
Computer Aided Drafting) software application for
2D and 3D design and drafting.
Commands:
1. Tool Bar
2. Pull Down
3. KEY COMMANDS
4. From the Key board

19. AutoCAD
Toolbars:
(from left to right):
Line, Construction Line, Poly Line, Polygon, Rectangle, Arc, Circle, Spline,
Ellipse, …, Block, …., Point, Hatch, Region, Table, Text
Modify Toolbar:
(from left to right):
Erase, Copy, Mirror, Offset, Array, Move, Rotate, Scale, Stretch,
Lengthen, Trim, Extend, Break at point, Break, Chamfer, Fillet, Explode

23. Q&A