Friday, March 30, 2007

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.

Source

Thursday, March 29, 2007

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.

Tuesday, March 27, 2007

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








Monday, March 26, 2007

Surveying, Mapping and GIS: Rwanda#links

Surveying, Mapping and GIS: Rwanda#links

Utility Mapping

Major investments need to be made in society’s utility supply lines; Water mains, sewage systems, telephone lines, power lines, gas mains, etc. Often the geographic location is recorded on inferior quality maps and in some cases it is not documented at all.Certainty of supply, environmental protection and efficiency of operations, however, require good basic data. Excavation damage can be largely avoided when reliable information regarding location and description of pipelines is available. Repair and replacement of pipes can be carried out in the optimal manner when based on an efficient information system.Additional advantages are achieved when the pipelines are captured in digital form, for instance providing:

Systematic data structuring.
- Quick access to information.
- Simple comparison of data for different pipelines and topography
- Flexible access to data retrieval and analysis.
- Efficient updating.
- Possible linkage to alpha-numeric databases e.g. consumer - Information and statistics.

Mapping of transmission lines includes establishment, use and maintenance of an information system consisting of:

- Location data i.e. geographic location of the
utility transmission.
- Attribute data i.e. technical and administrative data regarding transmission lines, e.g. component type, size, age and ownership.

The location should be surveyed and registered in relation to ground control points. It is thus possible to compare and present different types of transmission line data, base map data and other types of data such as information on cadastral ownership.

It has been proven that it is cost-effective to build up a uniform and systematized register of information on public utility transmission lines. Over the years Dimension India has built up considerable expertise in data capture for utility mapping as well as interpreting and digitizing information on many types of transmission lines, e.g.:

- Water mains
- Telephone lines
- Sewers and discharge pipes

One of the advantages to a utility company, when employing a Consultant to carry out
utility mapping, is that the bulk of work in connection with data capture can be carried out within a short period of time without staff increases or extra investments in equipment, thus easing the introduction of digital techniques.

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

GIS Mapping Services


This is probably the most asked question posed to those in the Geographic Information Systems (GIS) field and is probably the hardest to answer in a succinct and clear manner. "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 operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps."

GIS IN BUSINESS

Many businesses are using GIS for target marketing, competitive analysis, demographic analysis, risk management, route planning, and expansion analysis.

HEALTH CARE

The health care industry is successfully using GIS for marketing and promotion, research and planning, facilities management, and finance.

GOVERNMENT

Local, State, and Federal governments use GIS for economic development, legislative reform, voter registration and administration, zoning and land use controls, and emergency route management, just to name a few uses.

LOGISTICS

Organizations with delivery vehicles can use GIS for routing and scheduling, facilities management, vehicle tracking and dispatch, and warehouse operations.

AGRICULTURE

GIS is being used in agricultural business for production analysis, precision farming, runoff and non-point source pollution control, regulatory compliance, and financial modeling.

EDUCATION

Higher education and K-12 have used GIS for administration, school district remapping and student assignment, research, teaching, and community services.

TELECOMMUNICATIONS

Telecommunications companies have implemented GIS for target marketing, wireless engineering, customer support, outside plant engineering, construction management, and communication network routing and operation.

GAS & ELECTRIC

Gas and Electric companies use GIS for marketing, customer service, transmission and distribution system management, power generation and load management, meter reading, billing and collection, finance, operations, and engineering planning and design.

PETROLEUM

GIS is in use by the Petroleum Industry for retail, distribution, facilities management, and exploration.

ENVIRONMENTAL MANAGEMENT

GIS is an integral part of environmental management today. GIS can be used for site remediation, natural resource management, waste management, water quality, groundwater modeling, and vegetation mapping.

PUBLIC SAFETY

GIS forms an integral part of the emergency response mechanisms in place in most large-scale E-911 installations. The GIS is used to assist in real-time emergency response, in addition to being used for planning the response to future man-made or natural disasters.

PIPELINE

Building a pipeline may require GIS for risk management, market analysis, route planning and construction, and operation and maintenance once the pipeline has been put into service.

Forestry

GIS has been emerging as a strong tool for many areas of forestry, from harvesting schedules to urban forestry.

Real Estate and GIS

Resources to finding out about the application of GIS in the real estate industry and market analysis.

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