Wednesday, February 1, 2012

Digital Mapping: New Age Mapping Techniques

The collection of data and compiling it into a virtual image is called digital mapping or cartography. Maps which give accurate representations of some particular areas are produced through this process. It gives major details of roads networks and other interest points. Distance from a certain point to another is calculated through this technology.

Digital Mapping in the Digital Age

A variety of computer applications use this technology e.g. Google Earth. The maps are used in GPS satellite network which is used in the automotive navigation systems.

A terrestrial GPS receiver obtains the coordinates, position and atomic time from at least twenty four GPS satellites that do orbit the earth.  They interact together to provide digital mapping and programming.  The information provided has points of origin and the destination points needed in order to calculate the distance.

A map is later created from the analysis of the information. These maps give the easiest and the most efficient way to pass to reach a certain destination. The GPS coordinates (latitudinal and longitudinal exact points) are provided by the GPS receiver. The outputs of the coordinates approximately range between 10 to 20 meters of the actual location.  The beginning point that is entered via the coordinates and the ending point i.e. coordinates or the address input by the user, are later entered into the digital map. The route is represented by the map output in terms of real-time visual representation. Moving along this path that is provided helps the driver to move to the designated route. In case the driver drifts to the wrong route the navigation system recalculates a route to the destination location by use of the current coordinates.

Digital maps mostly rely on large amount of data that is collected over a certain period of time. These maps are mostly used in GPS navigation systems, scientific applications and also in computer applications.

Monday, January 30, 2012

The Advantages of Digital Orthophotography

You might have already heard of digital orthophotography. Well, its increasing popularity can be rooted from the growth in demand of the Geographic Information System (GIS) technology. Basically, what digital orthophotography has already done is that, it has provided a precise method in constructing a GIS database. Today, many people are seeking for the complete digital orthophotography services. Yet, it is a better idea if the person who wants to order the said service to have a better understanding of orthophotography. One has to ask: “Is digital orthophotography significant?”

Advantages of Digital Orthophotography

There are a lot of advantages in using an orthophotography. One is, when compared to the conventional line mapping, it is a more cost-effective mapping tool. This technique has already proven itself to inexpensively form an excellent base for GIS. It is also good to note that, the speed of the technique is amazingly high, making the map production quick as well. Also, features on the image are correctly measured, making it the favorite technique of many.

When using the technique, you can have options in storing the image created: either in digital or analog form. This, of course, depends on the preference of the person doing the technique.

Another wonderful feature of digital orthophotography is that, it has no image generalization. This means that, it does not contain a generalization of the cartographer which, in the case of the conventional vector map, is usually not complete. With the digital orthophotography, anyone who views the map can able to depict what is on the image clearly.

When it comes to reliability, the orthophotos have it. In fact, they are already used by a lot of people who want to map areas which are not accessible. Thus, these has made assessing any kind of change in a certain area possible.

Again, the digital orthophotography has proven itself to be vital in many ways. With its existence, it has made mapping more exciting, reliable and useful as well.

Tuesday, January 17, 2012

The Uses of High Resolution Aerial Photography

There are already a lot of uses for high resolution aerial photography these days. First of all, in making digital maps and 3d maps, this has been commonly used already. With the help of the process, there is an accurate location of areas, streets and all other establishments that should be placed in the map down to the very details. In the past, trusting how they are viewed from land will not necessarily give an accurate image. It will not also put everything in the right order. However, with high resolution aerial photography, everything can now be viewed at in the right way.

The application of high resolution aerial photography has now gone so extensive. It is used not only for mapping but for different governmental use as well. It has also been used for Science. Taking shots of images from space has also made use of high resolution aerial photography. This allowed them to take clearer images and more accurate photos. It has also been used for construction and engineering. The actual process might be quite costly and could take time. However, the camera being used here works in such a way that it will capture a series of images from where it stands and allows different angles and views to be taken right away. Thus, those who deal with it do not have a hard time.

High Resolution Aerial Photography

The camera used here is also very expensive as it is a product of the latest technology. Yet, with how it works and the accuracy it provides, it nevertheless became very common a technology already. This field might be a bit young and novel for now. However, it continues to improve. Sooner or later, it might expand its applications and it will be appreciated even more. Indeed, photography has gone very far.

Tuesday, January 10, 2012

The Benefits of Using San Diego GIS

It is undeniable that San Diego is one of the leading cities all over the country. It is also one of the most organized cities. However, back then, San Diego was not always what it is like now. There are also a lot of problems being experienced from time to time. This is basically in line with management of different departments of the government. Say for instance there are problems on the street.

One department will respond to it by making the street and in another time, the street will be broken since another department will be there to dig up cables. This would only accumulate more costs for the government and of course, lesser efficiency.

This paved the way for the use of the San Diego GIS to be started. GIS stands for Geographic Information System. This is like a digital map where all information about the streets is placed.

Say for instance there will be people calling for assistance with a broken streetlight. Before the call center employee would actually dispatch a person to fix the problem, the GIS will be checked first. This states the actual location of the streetlight and all other necessary details. When it has been confirmed that there really is a problem, they will then send people to work things out. By then, there will be no miscommunication and problems on people driving their way to the streets just to find out that there is no problem.

The use of GIS in San Diego today has expanded to a large size and even the public has now made use of the system in so many different ways. Indeed, running a huge city might be difficult. However, making use of a system that will make everything fall into place will definitely do wonders. It might not have been taken positively at first, but now it has strongly affected the entire city.

Tuesday, December 27, 2011

An Overview of 3D GIS

3D geographic information systems are systems that are designed with the purpose of capturing, storing, manipulating, managing, analyzing, and presenting 3 dimensional geographic data. Using this technology, people can manage geographic locations easier by viewing and analyzing geographic properties of the land through software or computer applications utilizing 3D GIS.

3D Geographic Information Systems in Detail

In essence, 3D GIS offers a new approach in producing or utilizing maps that are necessary in managing communities or certain industries. 3D GIS creates maps that are rich in information which can be used to aid in complicated geographic planning and strategical analysis. Using the system, planners can view geographic properties of the land they are working on making their jobs easier.

The 3D Geographic information system is a very popular technology utilized by the scientific community, natural resource management groups, environmental study groups, urban planners, hazard study groups, law enforcement, habitat mapping, as well as the military.

Many may not know this but many governments and agencies nowadays that deal with location and geographic management and studies are shifting their attention to using 3D technologies to aid them in their objectives. There are many limitations to the traditional 2D GIS technology and many problems faced by GIS users could only be solved using 3D GIS systems. As such, most GIS software are updating their systems to adopt 3D technologies because 2D GIS systems are now beginning to be considered obsolete.

Benefits of 3D GIS Mapping

What is great about 3D GIS is the ability to share maps. 3D GIS maps used by different organizations can be shared. This does not only save time, money, and effort which could have been spent developing new maps, it also allows the creation of maps with standardized details and information. This allows 3D GIS users to create and use more and more new maps without having to spend so much.

Tuesday, October 18, 2011

Remote Sensing

Acquisition of information about a certain phenomenon or an object without making any physical contact with it is called remote sensing. It generally refers to the use of aerial sensor technologies that do detect and also classify objects in the atmosphere, earth surface and also in the oceans through some propagated signals, for example satellites or electromagnetic radiation that is emitted from an aircraft.

Passive Remote Sensing

When passive sensors are used to detect natural radiation that is reflected or emitted by an object or the surrounding area is called passive remote sensing. Sunlight that is reflected by objects or surrounding areas is the most common source of radiation that is measured by the passive sensors. Infrared, photography, charge-coupled devices and radiometers are examples of passive remote sensors.

Active Remote Sensing

Active remote sensing is where some energy is emitted in order to scan objects and areas. The sensor then detects and also measures the radiation that is back-scattered or reflected from the target.

The LiDAR and the RADAR are examples of active remote sensing where the time delay between emission and the return is measured, the location, height, speed and the direction of the object are also established.

Advantages of Remote Sensing

One of the advantages of remote sensing is that it’s possible to collect data in dangerous and inaccessible areas.
There are various applications of remote sensing that includes monitoring deforestation in areas like the Amazon Basin, depth sounding of coastal  and ocean depths, and glacial features in Antarctic and the Arctic regions.

The military use remote sensing in times of war to collect data in dangerous areas. It also replaces slow and costly data collection on the ground and it ensures that objects or areas are not disturbed in the process. Data collected is used to analyze and compare things like pollution, forestry, erosion, land use and weather among other uses.

Thursday, October 6, 2011

Digital Photogrammetry - A Brief Overview

Digital Photogrammetry
Photogrammetry is the study of overhead images to determine topographical properties.  Digital Photogrammetry is the use of computers to ascertain the measurements of objects in these overhead images.  The images are carried out primarily from airplanes that can take overlapping photographs or videos of a given area to get full coverage of what is required.  Satellites can also be used to produce the images.

What is Digital Photogrammetry?

Digital Photogrammetry is used with photogrammetric software to calculate spatial relationships.  Most commonly used for the creation of topographical maps, it is also used in architecture, plastic surgery, manufacturing, forensic investigation and by the military forces.  The military make great use of digital photogrammetry to plan missions, track fugitives and direct missiles.

Important Variables to Digital Photogrammetry

In digital photogrammetry there are several variables that are of importance.  The first point is the necessity of the photogrammetrist to have a full working knowledge of the camera or video involved.  This is important as the type of camera, the focal length of the lens and/or the distance from the camera to the point of interest is critical.  Often a special type of camera, called a metric camera is used to take these photographs as it is calibrated to be able to take images with very minimal lens distortion.

The second point to note well when working with digital photogrammetry is the desired result that is required of the images.  Two dimensional (2D) measurements such as the height of a mountain or the width of estuary may be all that is required many projects and can be determined from single images.  However, if a three dimensional (3D) measurement is required such as the width, length and height of a building, then the process becomes a lot more detailed as it requires information from a lot more photographs.

Stereophotogrammetry - 3d Modeling

The procedure of creating 3D models is another field again, known as stereophotogrammetry.   Stereophotogrammatetrists are able to analyze several photographs taken of the same object from a variety of angles.  Common points of reference shared by the photographs or where they overlap allow them to create a digital 3D model.  These images can then be mapped together, megapixel by megapixel to create an image of measurable space in each of the three dimensions.

The third critical variable to take into account is the type of photographs used.  These are usually video or still digital camera photographs.  Videos need to be uploaded into computers to allow them to be used in digital photogrammetry.

Types of Photographs Used in Digital Photogrammetry

3d laser modeling
Two main types of photographs used are aerial and close- range photography.  Obviously aerial images are taken from a fixed video or digital camera mounted underneath an airplane.  Topographical mapping is done by using this technique.  The airplane flies over a given area of coordinates on a meandering flight path so as to enable the images to be overlapped.

Close- range or terrestrial digital photogrammetry uses images taken from closer proximity with hand held or tripod mounted cameras.  This is what allows the third dimension to be utilized- giving the means whereby 3D laser modeling of items such as buildings can be used portraying designs in development proposals.  This method is also used on movie sets when creating scenes.

In general, digital photogrammetry is a very important field to determine many factors in varied areas of applications.  Without it, it would be very difficult to create architectural images, create accurate maps, create movie scenes, direct armed warfare and to observe global changes as they occur.