Image Processing

Image Resolution
Resolution can be defined as "the ability of an imaging system to record fine details in a distinguishable manner". A working knowledge of resolution is essential for understanding both practical and conceptual details of remote sensing. Along with the actual positioning of spectral bands, they are of paramount importance in determining the suitability of remotely sensed data for a given applications. The major characteristics of imaging remote sensing instrument operating in the visible and infrared spectral region are described in terms as follow:

• Spectral resolution


• Radiometric resolution


• Spatial resolution


• Temporal resolution
  

Feature Extraction
Feature Extraction does not mean geographical features visible on the image but rather "statistical" characteristics of image data like individual bands or combination of band values that carry information concerning systematic variation within the scene. Thus in a multispectral data it helps in portraying the necessity elements of the image. It also reduces the number of spectral bands that has to be analyzed. After the feature extraction is complete the analyst can work with the desired channels or bands, but inturn the individual bandwidths are more potent for information. Finally such a pre-processing increases the speed and reduces the cost of analysis.
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Topographic Mapping

One of the most widely used of all maps is the topographic map. The feature that most distinguishes topographic maps from maps of other types is the use of contour lines to portray the shape and elevation of the land. Topographic maps render the three-dimensional ups and downs of the terrain on a two-dimensional surface.

Topographic maps usually portray both natural and manmade features. They show and name works of nature including mountains, valleys, plains, lakes, rivers, and vegetation. They also identify the principal works of man, such as roads, boundaries, transmission lines, and major buildings.The wide range of information provided by topographic maps make them extremely useful to professional and recreational map users alike. Topographic maps are used for engineering, energy exploration, natural resource conservation, environmental management, public works design, commercial and residential planning, and outdoor activities like hiking, camping, and fishing.

Topographic maps are different from other maps because they show the shape and elevation of features of landscape such as mountains and valleys. Here, you will investigate what the elements of a topographic map are, and how they are used.

- Topographic mapping is a vital resource for a wide range of applications including
- emergency and disaster response,
- national defence,
- asset and facilities management,
- demographics analysis,
- environmental monitoring,
- mineral and energy exploration,
- fleet and logistics management,
- graphic presentation of thematic data,
- infrastructure planning,
- other map production,
- market analysis, navigation and positioning,
- route planning,
- risk assessment,
- surveillance, and
- teaching.

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Parcel Mapping

Geographic Information System (GIS) is an accurate map delineating land parcel ownership. Many states have strict requirements for this mapping, as an accurate cadastral map is commonly a primary tool in the assessment of land values for tax purposes. In a digital format and linked to an assessment database, the GIS user can quickly query a variety of features. The quality of this mapping affects the confidence the user has in analysis results. Good decisions are based on good data.

A "parcel map" is a legal mechanism to subdivide real property into smaller parcels. In certain circumstances, there is a limit to the number of parcels that can be created by using the parcel map process. Typically, a maximum of four (4) residential parcels can be created with a parcel map. Consequently, the required improvements to the infrastructure are considerably less than that required of larger projects.

The parcel map process is typically used by landowners who are not "developers," but who happen to have a large piece of property and desire to create smaller parcels. A landowner can only use the parcel map process once, in most circumstances, otherwise future divisions of the same or adjacent property by the same property owner will require a tract map

The cadastral map has four main purposes:
1.) Provides a cartographic record of official and sometimes private land surveys and subdivisions.
2.) Facilitates the administration and transfer of Crown Lands.
3.) Records land ownership.
4. )Assists in the valuation and taxation of land
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Contour Mapping

What are Contours?

Contour lines connect a series of points of equal elevation and are used to illustrate topography, or relief, on a map. They show the height of ground above Mean Sea Level (M.S.L.) in either feet or metres and can be drawn at any desired interval. For example, numerous contour lines that are close together indicate hilly or mountainous terrain; when far apart, they represent a gentler slope

Contour Mapping

Topographic maps use contour lines to indicate the shape and elevation of these landscape features because it is difficult, as we have already discovered, to show three-dimensional objects, like hills and valleys, on a two-dimensional surface, like a map. Contour lines are lines that connect the location of equal measures of elevation.

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Thematic Mapping

Various types of thematic maps can be created. These themes can be assigned meaningful colors and the legend control can be used to see the legend of the themes created. Thematic mapping refers to the creation of maps, which emphasize specific characteristics of a given geographic area. Thematic maps are particularly well suited for presenting complex information in an understandable format. Making complex information understandable is a primary purpose of any map geared toward the general public.

Different types of Themes that can be created are as follows:

1.) Ranges

The ranges theme divides the data on the basis of number of ranges defined. The user can specify the colors to be used with each particular range unit.

This ranging is based on one of the following techniques:

- Equal Ranges: The entire range is divided into equal spaced sections and the theme is created on the basis of it
- Equal Count: The total numbers of units, which are being considered for creating the theme, are divided into equal sized groups and the theme is generated on the basis of that.
- Quantile: The entire data set is divided into quantile groups and the ranging is done on the basis of it.

- Graphs: Thematic maps in the form of bar graph and pie charts can be created.

* Bar Graph
* On specifying the Graph theme type to bar chart the theme generator creates bars corresponding to each specified field of theme creation.

2.) Pie Charts

On specifying the chart theme type to pie chart the theme generator creates a pie with each specified field forming a part of the pie. This kind of theme is generally used when comparing values and observing the amount of share each field has in the entire group.

3.) Individual

The individual theme is used to create themes where each individual value is given a unique color. This kind of thematic maps are used when mapping a large dataset and trying to find out similar values.

4) Graduated

Themes are created on the basis of a single symbol as selected by the user and representing it in various sizes to represent the corresponding value.

5) Dot Density

Themes are created in the form of collection of dots where each dot represents a certain value the numbers of dots gives an idea of the population of the value being represented.

Source :- http://www.dimensionicad.com

AM/FM

We provides a wide range of data conversion services to complement Geospatial Technology Applications for Automated Mapping/Facilities Management (AM/FM) projects and Geographical Information Systems (GIS) which include:

- Raster-to-vector conversion, time taking works like drafting corrections, updates, geocoding etc
- Database designing and modeling
- Spatial Analysis and query
- Building of rule-based feature connectivity models
- Re-mapping of facilities on a land base into different coordinate systems
- Integration of map feature and attribute data from multiple and sometimes conflicting sources and documents
- Development of digital land base maps; inclusive of planimetric, topographic, and cadastral features.
- We have the knowledge base and the expertise to implement AM/FM & GIS systems on a variety of software platforms: Intergraph, ESRI, Smallworld, AutoDesk, and Bentley Systems etc. We are flexible to work on software specified by our clients for specific jobs.

Source :- www.dimensionicad.com

Remote Sensing

Remote Sensing is the science and art of acquiring information (spectral, spatial, temporal) about material objects, area, or phenomenon, without coming into physical contact with the objects, or area, or phenomenon under investigation. Without direct contact, some means of transferring information through space must be utilised. In remote sensing, information transfer is accomplished by use of electromagnetic radiation (EMR). EMR is a form of energy that reveals its presence by the observable effects it produces when it strikes the matter. EMR is considered to span the spectrum of wavelengths from 10-10 mm to cosmic rays up to 1010 mm, the broadcast wavelengths, which extend from 0.30-15 mm.

Types
1) In respect to the type of Energy Resources: Passive Remote Sensing: Makes use of sensors that detect the reflected or emitted electro-magnetic radiation from natural sources.Active remote Sensing: Makes use of sensors that detect reflected responses from objects that are irradiated from artificially-generated energy sources, such as radar.

2) In respect to Wavelength Regions:

Remote Sensing is classified into three types in respect to the wavelength regions
- Visible and Reflective Infrared Remote Sensing.
- Thermal Infrared Remote Sensing.
- Microwave Remote Sensing.

This technique may be the most effective way to collect the information. Aerial Photographs and Imagery carry huge amounts of analogue data. When interpreted, they can provide valuable information. This technique is helpful for environmental data, plan more detailed field investigations, discover certain classes of properties, map sites, locate and confirm the presence of predicted sites.

- PAN Images
- LISS III
- IKONOS

Source :- http://www.dimensionicad.com