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विजया दशमी २०७९ साल को सुखद उपलक्ष्यमा साथीभाइ, ईस्ट्मित्र,आफन्तजनहरुलाई सुख , शान्ति एवं समृद्धि का लागि हार्दिक मंगलमय शुभकामना व्यक्त गर्द्छु। दशरथ सिंह महत मार्मा गाँउपालिका ४ दार्चुला मार्मा मठ्खोला

 

GIS

Geographic Information System (GIS)
A geographic information system (GIS) is a
computer based tool for mapping and analyzing
things that exist and events that happen on earth.
GIS technology integrates common database
operation such as query and statistical analysis
with the unique visualization and geographic
analysis benefits offered by maps.
These abilities distinguish GIS from other
information systems and make it valuable to a
wide range of public and private enterprises for
explaining events, predicating outcomes, and
planning strategies. How does it (GIS) work?
GIS stores information about the world as a
collection of thematic layers that can be linked
together by geography. This simple
but extermly powerful and versatile concept has
proven invaluable for solving many real-world
problems from tracking delivery vehicles, to
recording details of planning applications, to
modeling global atmospheric circulation.
Geographic References:
Geographic information contains either an explicit
geographic reference, such as a latitude and
longitude or national grid coordinate, or an implicit
reference such as an address, postal code, census
tract name, forest stand identifier, or road name.
An automated process called geocoding is used to
create explicit geographic references from implicit
references. These geographic references allow you
to locate features, such as a business or forest
stand, and events, such as an earthquake, on the
earth's surface for analysis.
Vector and Raster Model:
GIS work with two fundamentally different types of
geographic models: the 'vector' model and 'raster'
model. In the vector model, information about
points, lines, and polygons is encoded and stored
as a X,Y coordinate. Linear features, such as
roads and rivers, can be stored as a collection of
point coordinates. Polygonal features, such as
sales territories and rivers catchments, can be
stored as closed loop of coordinates.
The vector model is extremely useful for describing
discrete features, but less useful for describing
continuously varying features such as soil type or
accessibility costs for hospitals. The raster model
has evolved to model such continuous features. A
raster image comprises a collection of grid cells
rather like a scanned map or pictures. Both are
vector and raster models for storing geographic
data have unique advantages and disadvantages.
Modern GISs are able to handle both models.
Components of GIS:
Hardware: Hardware is the computer on
which a GIS operates. Today, GIS
software runs on wide range of hardware
types, from centralized computer servers
to desktop computers used in stand-aline
or networked configurations.
Software: GIS software provides the
functions and tools needed to store,
analyze, and display geographic
information. Software components are
given below:
1. Tools for the input and manipulation of
geographic information
2. a database management system (DBMS)
3. tools that support geographic query, analysis,
and visualization
4. a graphical user interface for easy access to
tools.
component of GIS is the data. Geographic
data and related tabular data can be
collected in house or purchased from a
commercial data provider. A GIS will
integrate spatial data with other data
resources and can even use a DBMS,
used by most of organizations to
recognize and maintain their data, to
manage spatial data.
without the people who manage the
system and develop plans for applying it
to real world problems. GIS users range
from technical specialists who design
and maintain the system to those who
use it to help them perform their
everyday work.
according to a well designed plan and
business rules, which are the models and
operating practices unique to each
organization.

Remote sensing

The Remote Sensing and Geographic Information
Systems (RS&GIS) Field of Study (FoS), Asian
Institute of Technology (AIT), Thailand, offers
graduate program leading to Master’s and Doctoral
degrees. We also offer training and certificate
programs for capacity building in RS&GIS and it’s
application in many fields.
Our faculty members are involved in leading
Research in all areas of Remote Sensing and GIS,
covering such diverse areas as Space System
Engineering, Image Processing for Environmental
Data Analysis, Disaster Mitigation: Earthquake,
Erosion control, Terrain modeling, Automated
Mapping, Remote Sensing and GIS Applications, 3D
Modeling, Online Spatial Database System,
Modeling of Geomorphic Processes, Digital
Elevation Models (DEMs), Applications of Remote
Sensing and GIS in Resources Management,
Photogrammetry, Computer Mapping, NOAA Data
Receiving and Processing, Automated Mosaicings,
Optical RS, Web based GIS, Environmental
Information Extraction and Validation, Social
Environmental Change detection, Automatic Pattern
Recognition, Remote Sensing and GIS development
etc.
The RS&GIS FoS has strong interactions with
international research agencies and government
departments such as JAXA and JICA of Japan,
CIRAD and IRD of France, European Union.

Arcgis server

Make It Simple for Your Users to Get the
Information They Need
The geographic information that you make
available using ArcGIS for Server can be accessed
via a variety of ready-to-use apps and templates.
You can configure simple, focused user experiences
so people can get their jobs done quickly and
intuitively.

GPS navigation

MapFactor Navigator is a free turn-by-turn GPS
navigation app for Android with postcodes and free
GPS maps from OpenStreetMaps. These free maps
and postcodes are installed on your device or SD
card so you do not need an Internet connection
when traveling. Free Maps are updated every
month for FREE.
MapFactor also makes the popular NavigatorFREE
GPS navigation software for PC, Pocket PC and
WinCE, also with postcodes and free maps from
OpenStreetMaps.
OpenStreetMaps are created and updated by the
community at www.osm.org.
Optional TomTom GPS navigation maps and
postcodes are also available.
If you wish to get help or provide feedback to our
GPS navigation app, please email android@
mapfactor.com.
Key features of the Mapfactor GPS Navigation App:
Voice guidance
* intuitive voice navigation in different languages
* door to door route planning
* cross-border routing without the need to switch
between countries or to a less detailed maps
* overview of the upcoming manoeuvre and
distance shown on the screen
GPS satellite navigation
* 2D/3D mode allows realistic visual maps display
* day/night modes switch colour schemes for day
or night time driving
* GPS maps rotate in driving direction, or north up
Searching

Sources of GPS signal errors

Sources of GPS signal errors
Factors that can degrade the GPS signal and thus
affect accuracy include the following:
Ionosphere and troposphere delays - The
satellite signal slows as it passes through the
atmosphere. The GPS system uses a built-in
model that calculates an average amount of
delay to partially correct for this type of error.
Signal multipath - This occurs when the GPS
signal is reflected off objects such as tall
buildings or large rock surfaces before it reaches
the receiver. This increases the travel time of the
signal, thereby causing errors.
Receiver clock errors - A receiver's built-in clock
is not as accurate as the atomic clocks onboard
the GPS satellites. Therefore, it may have very
slight timing errors.
Orbital errors - Also known as ephemeris errors,
these are inaccuracies of the satellite's reported
location.
Number of satellites visible - The more satellites
a GPS receiver can "see," the better the
accuracy. Buildings, terrain, electronic
interference, or sometimes even dense foliage
can block signal reception, causing position
errors or possibly no position reading at all. GPS
units typically will not work indoors, underwater
or underground.
Satellite geometry/shading - This refers to the
relative position of the satellites at any given
time. Ideal satellite geometry exists when the
satellites are located at wide angles relative to
each other. Poor geometry results when the
satellites are located in a line or in a tight
grouping.
Intentional degradation of the satellite signal -
Selective Availability (SA) is an intentional
degradation of the signal once imposed by the
U.S. Department of Defense. SA was intended to
prevent military adversaries from using the
highly accurate GPS signals. The government
turned off SA in May 2000, which significantly
improved the accuracy of civilian GPS receivers.