GIS has become somewhat mandatory. Our day-to-day myriad activities of life cannot go on without the helping hands of GIS.
Developed recently for the purpose of using and studying geographic information, geography underpins GIS and is the key to understanding it. It expresses and describes the locations of objects and features relating to the distribution and patterns of physical and human features that exist on the Earth’s surface.
Modern GIS
Before the advancement of modern GIS, analysis procedures would have been manually undertaken using transparent overlays or run through very slow and incompetent machines with far less power than today’s machines. GIS in the past mainly meant the information obtained from maps.
The indispensable advantage of modern GIS is that all the functionality for working with manifold sets of geographic data are assembled and automated within one piece of software with improved efficiency and speed.
The input, storage and display of geographical information are now realized in a computer and hence the features and themes can be manipulated, combined and analyzed to generate new information.
Different GIS software packages are available with different functionality and interfaces. ESRI is the world’s most popular GIS software package.
Common examples of GIS
Geographic information is as wide and varied from socio-economic or demographic data to physical and environmental data, treated as separate l ‘themes’ of similar types of information. Eg: Physical features or phenomena such as rivers, roads, forests, earthquakes, volcanoes, erosion, floods, vegetation etc. and Human features or phenomena such as population, migration, electoral territories, poverty, religion, health etc.
One such theme could relate to all the ‘rivers’ in a country. The physical features can include flooding and pollution. The location element is the postcode.
One of the main sources of ‘human’ geographic information is the Census. It records a large number of variables about every person in the a country including employment, housing and health. The geography element of it is the location of where people live.
Essentially, geographic information states WHAT is WHERE which needs to record these two elements somehow. Data can be captured from aerial photography, satellite images, field samples, land surveying, population censuses, global positioning systems (GPS) and government administrative records among others.
For combining geographic information themes, geography or location is used as the common denominator or the link. It has the potential to generate new information on patterns and relationships between multiple sets of geographic information that would otherwise be missed, and to aid in answering more complex questions or decision-making.
A typical example is Jon Snow’s investigation of Cholera in Victorian London in 1854. He identified the locations of incidences of Cholera against the location of water pumps, and noticed its gathering pattern around the Broad Street water pump. He identified the contaminated source and created the beginning of modern epidemiology. A map of just the water pumps or incidences of Cholera alone would have been of little value.
Again take the example of flood risk maps where the combined geographic information on the locations of properties and the locations of flood zones can help to identify properties at risk of flooding. This combined information is of huge value to environmental groups and insurance companies providing new information that would not be detectable otherwise.
Modern GIS has several advantages over the old techniques of map-making and information gathering. Some of modern GIS are:
1.Can cover large study areas (the whole world if necessary)
2.Deal with larger amounts of data
3.Can easily select any sub-study area
4.Can cope with frequent and infinite edits and changes
5.More powerful and resistant to damage
6.Quicker and more efficient
7.Less person, time and money
The Census is the most familiar examples of how GIS can store and display a number of large datasets for the entire country quickly and easily. Without the help of GIS, you would have had to search manually through records on your computer on telephone staff at the Census office to get information about your area of interest.
With GIS, data for any area can be accessed quickly and easily according to a location. We can now store and show maps and aerial photographs covering the whole of a country. For example, Multimap through which you can know exactly where every town and village in the UK was, you would be unable to provide the level of information that Multimap is able to do in just a few seconds. Essentially, you are able to customise your data to suit your needs.
GIS software has a large variety of tools of varying levels of complexity. Shown below are some core standard functions common to GIS software packages.
Query: Ask questions of feature attributes like: where is _? What’s the nearest_? What intersects with _?
Mapping and cartography: Visualize features and edit symbology and colours to create an output map with title, scale bar, north arrow etc.
Select: Classify features and their attributes that meet some criteria.
Distance: Estimate the distance between features.
Buffers: Rings drawn around features at a particular distance from the features.
Overlay: The display of diverse layers of information at one location.
Clip: Makes an input layer to the size and extent of a selected layer.
Merge: Merges multiple layers into a single layer.
Raster analysis: A complete separate suite of tools for raster analysis which includes classifying cells, deriving aspect and slope, mosaicing and calculating new cell values among many others.
3D: Data can be analyzed with ‘height’ in 3-dimensions for powerful visualization
Who uses GIS and Why?
GIS has evolved into a technology that is used by a huge number of industries and agencies to help plan, design, engineer, build and maintain information infrastructures that effects our everyday lives.
Use of GIS in different industry
Forestry: Inventory and management of resources
Police: Crime mapping to target resources
Epidemiology: To link clusters of disease to sources
Transport: Monitoring routes
Utilities: Managing pipe networks
Oil: Monitoring ships and managing pipelines
Central and local government: Evidence for funding and policy (eg.) deprivation
Health: Planning services and health impact assessments
Environment agencies: Identifying areas of risk from e.g. flood
Emergency departments e.g. ambulance: Planning quickest routes
Retail: Store location
Marketing: Locating target customers
Military: Troop movement
Mobile phone companies: Locating masts
Land ReGIStry: Recording and managing land and property
Estate agents: Locating properties that match certain criteria
Insurance: Identifying risk e.g. properties at risk of flooding
Agriculture: Analyzing crop yields
Regards
SBL GEOMATICS
Showing posts with label Geomatics. Show all posts
Showing posts with label Geomatics. Show all posts
Tuesday, March 3, 2009
Monday, February 2, 2009
CAD services and Georeferencing
The word ‘georeferencing’ was originally used to describe the process of referencing a map image to a geographic location.
To describe it now, georeferencing is a process of taking an image and assigning geographic coordinates to it or to georeference something means to define its existence in the physical space by establishing a relation between raster or vector images to map projections or coordinate systems. When data from different sources need to be compiled and used in any GIS application, it is important to have a common referencing system. This is brought about by using various georeferencing techniques.
The process of georeferencing
Georeferencing usually refers to the method by which locations in raster and vector GIS files are related to real earth-surface positions.
Raster data is often taken by scanning maps or collecting aerial photographs and satellite images. Scanned map datasets usually do not have any spatial reference information. The location information delivered with aerial photography and satellite imagery might be inadequate and the data need not align correctly with some other data you possess.
In order to use some raster datasets in conjunction with other spatial data, you sometimes need to align or georeference them to a map coordinate system which can be defines using a map projection to display the curved surface of the earth on a flat surface.
Georeference a raster dataset means defining its location using map coordinates and assigning a coordinate system. This process allows it to be viewed, queried, and analyzed in comparison with other geographic data.
How can you georeference a raster dataset?
Add the raster dataset to be aligned to your projected data in ArcMap.
Add control points that connect known raster dataset positions to the map coordinate positions.
When the alignment becomes correct, save the georeferencing information (registration) for further use.
Though Geomatics users are familiar with the term ‘georeferening’, many of the CAD users are not much aware of the term and the use of georeferencing in CAD.
Why is it needed?
A raster image has no particular size as it is made up of pixels. The size of the vectorised CAD/GIS drawing is determined by the raster's pixel dimensions, without georeferencing. The image resolution (DPI) can determine this. This image size usually has no relationship with the size of the drawing that the raster represents.
A CAD file is usually drawn in a local coordinate system and depicts spatial information which can be drawn accurately without being fixed to a higher global coordinate system. However, when the drawing needs to be related to a higher level in a mapping context with data from many different sources, tools in ArcMap can easily reposition a CAD file and integrate it into that higher level without altering the CAD file.
First thing is to find out two points on the CAD file that matches with two points in the map for which we can use the Georeferencing toolbar in ArcMap.
Different tools on the toolbar can support different workflows and below listed is an easy way to describe georeferencing a CAD file.
First step is to load the CAD drawing and ensure that one of the CAD feature layers are listed in the drop down menu of the georeferencing toolbar.
Zooming to the place roughly on the map where the CAD drawing is to be related is the next step. You can use the ‘fit to display’ tool on the menu to fix the CAD file in the map frame.
ArcMap snapping helps accurate placement of the CAD file which makes precise selection of control points based on existing geometry. Use the ‘rotate’ tool if the CAD file needs to be rotated to get the drawing nearer to its final position. This enables easy picking of control points.
You can use the interactive scaling tool also for the above mentioned reason.
Now when you select the ‘update georeferencing’ option, this creates a .WLD file that will be read from now on to put your CAD file in the right place.
Finally, the coordinates are always adjusted into this position. Now you can select a coordinate system for your CAD drawing so that you can assign or project its coordinates with reference to the map or during any other geospatial operation.
Regards
SBL GEOMATICS
Article By : RARIMA N S
To describe it now, georeferencing is a process of taking an image and assigning geographic coordinates to it or to georeference something means to define its existence in the physical space by establishing a relation between raster or vector images to map projections or coordinate systems. When data from different sources need to be compiled and used in any GIS application, it is important to have a common referencing system. This is brought about by using various georeferencing techniques.
The process of georeferencing
Georeferencing usually refers to the method by which locations in raster and vector GIS files are related to real earth-surface positions.
Raster data is often taken by scanning maps or collecting aerial photographs and satellite images. Scanned map datasets usually do not have any spatial reference information. The location information delivered with aerial photography and satellite imagery might be inadequate and the data need not align correctly with some other data you possess.
In order to use some raster datasets in conjunction with other spatial data, you sometimes need to align or georeference them to a map coordinate system which can be defines using a map projection to display the curved surface of the earth on a flat surface.
Georeference a raster dataset means defining its location using map coordinates and assigning a coordinate system. This process allows it to be viewed, queried, and analyzed in comparison with other geographic data.
How can you georeference a raster dataset?
Add the raster dataset to be aligned to your projected data in ArcMap.
Add control points that connect known raster dataset positions to the map coordinate positions.
When the alignment becomes correct, save the georeferencing information (registration) for further use.
Though Geomatics users are familiar with the term ‘georeferening’, many of the CAD users are not much aware of the term and the use of georeferencing in CAD.
Why is it needed?
A raster image has no particular size as it is made up of pixels. The size of the vectorised CAD/GIS drawing is determined by the raster's pixel dimensions, without georeferencing. The image resolution (DPI) can determine this. This image size usually has no relationship with the size of the drawing that the raster represents.
A CAD file is usually drawn in a local coordinate system and depicts spatial information which can be drawn accurately without being fixed to a higher global coordinate system. However, when the drawing needs to be related to a higher level in a mapping context with data from many different sources, tools in ArcMap can easily reposition a CAD file and integrate it into that higher level without altering the CAD file.
First thing is to find out two points on the CAD file that matches with two points in the map for which we can use the Georeferencing toolbar in ArcMap.
Different tools on the toolbar can support different workflows and below listed is an easy way to describe georeferencing a CAD file.
First step is to load the CAD drawing and ensure that one of the CAD feature layers are listed in the drop down menu of the georeferencing toolbar.
Zooming to the place roughly on the map where the CAD drawing is to be related is the next step. You can use the ‘fit to display’ tool on the menu to fix the CAD file in the map frame.
ArcMap snapping helps accurate placement of the CAD file which makes precise selection of control points based on existing geometry. Use the ‘rotate’ tool if the CAD file needs to be rotated to get the drawing nearer to its final position. This enables easy picking of control points.
You can use the interactive scaling tool also for the above mentioned reason.
Now when you select the ‘update georeferencing’ option, this creates a .WLD file that will be read from now on to put your CAD file in the right place.
Finally, the coordinates are always adjusted into this position. Now you can select a coordinate system for your CAD drawing so that you can assign or project its coordinates with reference to the map or during any other geospatial operation.
Regards
SBL GEOMATICS
Article By : RARIMA N S
Tuesday, November 18, 2008
Advantages of Using GIS Services in Oil & Gas | Petroleum industry
The use of Geographic Information Systems (GIS) is gathering momentum in Oil and petroleum industry as a powerful tool for analyzing and displaying data.
Geomatics services can be applied in various stages during the development of projects, including: Petroleum Exploration, Production, Managing Facilities & Pipeline Management
Petroleum Exploration:
Gis facilitates the analysis and integration of a lot of different types of data such as satellite imagery, seismic surveys, digital aerial photo mosaics, surface geology studies, subsurface and cross section interpretations and images, well locations, and existing infrastructure information.Combined Image Processing can reveal underground Geological Information.The remote sensing detection of petroleum is based on the characteristic analogy and analysis of remote sensing information from known oil fields. The thinking way is as follows: micro-seeping of hydrocarbon- ground effect- remote sensing detection is certainly gainful. Exploration software and GIS are essential for geologists searching for petroleum and mineral deposits.
One specific exploration application involves the creation of reconnaissance maps. Uses of GIS in exploitation projects are perhaps more varied because exploitation evaluation typically deals with more extensive data sets than those typically used in exploration settings. Exploitation approaches are generally applied to mature producing areas where well control is dense, whereas exploration projects may not involve any wells at all. GIS is a particularly effective technology that enables exploration and exploitation teams to share information, analyze data in new ways, and integrate the evaluation process.
Production:
Innovative GIS technology is ideally suited for the overlay analysis of geographic, infrastructure, business conditions, and environmental factors and which can be integrated with other business risk or economic business planning engines to provide a focused business solution tool set.
Managing Facilities:
A large integrated oil company must keep track of every minute detail from drilling platforms to pipeline networks and to refineries for their advancement in this highly competitive business area. Geospatial information can be aptly used to map the gathering and transmission of products to a facility.
Pipeline Management :
Geomatics programs can be utilized to monitor the condition and flow of pipelines and determine the best pipeline locations to transport oil off the fields and to the refineries. Pipeline Management is a process by which you continually evaluate your active opportunities (from prospects to booked customer) for their balance of QUANTITY and QUALITY.
Some of the GIS solutions currently offered by SBL In Oil and Petroleum Industry:
1. 3D Modeling
2. Photogrammetry
3. Lidar Data Processing
4. GPS Navigation
5. Corporate GIS data management
6. Map production and presentation
7. Digital Elevation Modeling and Hydrological Modeling
8. Environmental sensitivity analysis and modeling
9. Network analysis
10.Pipeline route optimization and pipeline leakage risk
11.Internet mapping and image web server solutions
12.Work flow analysis
13.Conversion of data to GIS format
14.Linkage of oil spill model to GIS.
15.Retail market analysis.
16.Distribution analysis.
17.Market pattern analysis by demographics.
19.CAD Drafting and Designing
20.CAD to GIS conversion
Retail outlet supply routing and many more…
We hope you found it useful. For more information about the applications of GIS Services in various sectors Please visit the following link.
Gis Service Provider
Geomatics services can be applied in various stages during the development of projects, including: Petroleum Exploration, Production, Managing Facilities & Pipeline Management
Petroleum Exploration:
Gis facilitates the analysis and integration of a lot of different types of data such as satellite imagery, seismic surveys, digital aerial photo mosaics, surface geology studies, subsurface and cross section interpretations and images, well locations, and existing infrastructure information.Combined Image Processing can reveal underground Geological Information.The remote sensing detection of petroleum is based on the characteristic analogy and analysis of remote sensing information from known oil fields. The thinking way is as follows: micro-seeping of hydrocarbon- ground effect- remote sensing detection is certainly gainful. Exploration software and GIS are essential for geologists searching for petroleum and mineral deposits.
One specific exploration application involves the creation of reconnaissance maps. Uses of GIS in exploitation projects are perhaps more varied because exploitation evaluation typically deals with more extensive data sets than those typically used in exploration settings. Exploitation approaches are generally applied to mature producing areas where well control is dense, whereas exploration projects may not involve any wells at all. GIS is a particularly effective technology that enables exploration and exploitation teams to share information, analyze data in new ways, and integrate the evaluation process.
Production:
Innovative GIS technology is ideally suited for the overlay analysis of geographic, infrastructure, business conditions, and environmental factors and which can be integrated with other business risk or economic business planning engines to provide a focused business solution tool set.
Managing Facilities:
A large integrated oil company must keep track of every minute detail from drilling platforms to pipeline networks and to refineries for their advancement in this highly competitive business area. Geospatial information can be aptly used to map the gathering and transmission of products to a facility.
Pipeline Management :
Geomatics programs can be utilized to monitor the condition and flow of pipelines and determine the best pipeline locations to transport oil off the fields and to the refineries. Pipeline Management is a process by which you continually evaluate your active opportunities (from prospects to booked customer) for their balance of QUANTITY and QUALITY.
Some of the GIS solutions currently offered by SBL In Oil and Petroleum Industry:
1. 3D Modeling
2. Photogrammetry
3. Lidar Data Processing
4. GPS Navigation
5. Corporate GIS data management
6. Map production and presentation
7. Digital Elevation Modeling and Hydrological Modeling
8. Environmental sensitivity analysis and modeling
9. Network analysis
10.Pipeline route optimization and pipeline leakage risk
11.Internet mapping and image web server solutions
12.Work flow analysis
13.Conversion of data to GIS format
14.Linkage of oil spill model to GIS.
15.Retail market analysis.
16.Distribution analysis.
17.Market pattern analysis by demographics.
19.CAD Drafting and Designing
20.CAD to GIS conversion
Retail outlet supply routing and many more…
We hope you found it useful. For more information about the applications of GIS Services in various sectors Please visit the following link.
Gis Service Provider
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