introduction to gis

2.  In general, a GIS provides facilities for data
capture,
 data management,
 data manipulation
 and analysis,
 and the presentation of results
 in both graphic and report form,
 with a particular emphasis upon
preserving and utilizing inherent characteristics of
spatial data.

3.  An operational GIS also has a series of components that combine
to make the system work. These components are critical to a
successful GIS.
 A working GIS integrates five key components:
 HARDWARE,
 SOFTWARE,
 DATA,
 PEOPLE,
 METHODS

6.  A GIS topology is a set of rules and behaviors
that model how points, lines, and polygons
share coincident geometry.
 Steps- arc node topology
 Area defination
 Adjacency

14. 1. SPATIAL DATA- A- DISCREET DATA
 ( FEATURE BASE) B-CONTINUOUS DATA
 (GENERAL) A- RASTER DATA
B- VECTOR DATA
C- TIN DATA
2. NON SPATIAL DATA- NOMINAL
DATA,ORDIANAL DATA,INTERVA
DATA,RATIO DATA, CARTOGRAPHICAL
DATA, NUMERIC DATA

15.  GEOLOGICAL DATA
 SOIL DATA
 VEGETATION DATA
 LAND USE DATA
 WATER RESOURCES DATA
 LITHOLOGICAL DATA

18.  DATA ACQUISITION
 PREPROCESSING
 DATA MANGEMENT
 MANIPULATION AND ANALYSIS
 PRODUCT GENERATION

19.  Data acquisition is the process of sampling signals
that measure real world physical conditions and
converting the resulting samples into digital
numeric values that can be manipulated by a
computer.
 Sensors that convert physical parameters to
electrical signals.
 Signal conditioning circuitry to convert sensor
signals into a form that can be converted to digital
values.
 Analog-to-digital converters, which convert
conditioned sensor signals to digital values

20.  Analog-to-digital converter (ADC)- An electronic
device that converts analog signals to an equivalent digital form.
The analog-to-digital converter is the heart of most data
acquisition systems.
 Digital-to-Analog Converter (D/A) - An electronic component
found in many data acquistion devices that produce an analog
output signal.
 Digital Input/Output (DIO) - Refers to a type of data acquistion
signal. Digital I/O are discrete signals which are either one of two
states. These states may be on/off, high/low, 1/0, etc. Digital I/O
are also referred to as binary I/O.

22.  Data pre-processing describes any type of
processing performed on raw data to prepare it
for another processing procedure.

25.  A Database Management System (DBMS) is a set of
programs that enables you to store, modify, and extract
information from a database, it also provides users with
tools to add, delete, access, modify, and analyse data stored
in one location. A group can access the data by using query
and reporting tools that are part of the DBMS or by using
application programs specifically written to access the data.
 DBMS’s also provide the method for maintaining the
integrity of stored data, running security and users access,
and recovering information if the system fails. The
information from a database can be presented in a variety of
formats. Most DBMSs include a report writer program that
enables you to output data in the form of a report. Many
DBMSs also include a graphics component that enables you
to output information in the form of graphs and charts.
Database

28.  Coordinate Thinning.
 Geometric Transformations
 Map Projection Transformations
 Conflation - Sliver Removal
 Edge Matching
 Interactive Graphic Editing
 Conflation - Sliver Removal