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Geomatics services include:
- Digital Photogrammetry
- GPS Surveys
- GIS
- Remote Sensing
- LiDAR
The use of data for broad public purposes has become a way of life for most of North America and Western Europe. Demographics of a national census can be verified for accuracy by comparison with known housing stock identifiable from aerial imagery. The transportation and utility systems in areas of known volcanic, earthquake, typhoon or hurricane vulnerability can be modeled to predict deficiencies in capacity during catastrophic events. Property ownership information can be integrated with historic utility billing, utility system as-builts and aerially obtained topography to identify areas of low water pressure and model optional solutions. Alternative investment patterns can be used to predict the impact on valuable croplands.
These analysis, planning and basic design tools have enriched the quality of life for only those fortunate few who live in areas which have the means to secure and utilize such tools. The rest of the world watches and waits. EMI's primary reason for being in business is to harness the technology of geomatics for improving quality of life.
Digital Photogrammetry
Overview
The historical advancement of society can be directly correlated with the quality and accessibility of maps available to the general public for everyday applications. Mobility, commerce, the free exchange of ideas, leisure travel, investment, mitigation of hazards, natural resource exploration, record keeping, and social interaction are all facilitated. As maps became more detailed, widely distributed and understood, quality of life improved. Balance of power and quality of life disparities between countries were roughly a function of population size and literacy.
In more recent times the economic disparity between developed and undeveloped countries has widened to the point that many consider it dangerous and potentially detrimental to the long-term good of society as we know it.
The field of photogrammetry is a rapidly changing one with new technologies and protocols being developed constantly. In a relatively short period of time the practice of photogrammetry has gone from the analog world to digital. For over fifty years conventional practice has been to fly aerial photography, manually process the negatives, diapositives, contacts and prints, and laboriously view stereoscopic pairs to capture features and topography. Within the last ten years advances in computer technology, digital cameras, and ever-more high resolution remote sensing satellite images have allowed firms like EMI to develop geomatics technology for optimal utilization by different disciplines.
Unfortunately, the advances and specific applications realized in some of the western world are limited to a comparatively small percentage of the world's population. As an Asian-American owned, US-based firm, one of the chief aims of EMI is to share this technology with the rest of the United States, as well as with the broader international community.
The use of laser scanning allows for conventional aerial photography to be converted to digital format, which is then mathematically adjusted to yield high accuracy rectified images. Until now, this technology has been limited to very few organizations and applications. The vast majority of potential users and beneficiaries is either unaware or cannot use the technology because of high initial set-up and training costs. If used properly, these digital mapping techniques can result in lower costs and more practical products than conventional techniques provide. Color infrared (CIR) images have only been used for a limited number of research projects, but can now be used for many applications, including GIS basemapping.
The biggest hinderances to worldwide implementation of these technologies is a general lack of awareness of their availability and broad applicability; difficulty in transfer of this highly technical knowledge and training of others in the use appropriate methodologies and techniques; and resistance by champions of conventional processes, who have a vested interest in limiting process change. EMI exists to overcome each of these barriers, believing quality of life for all of society can continue to improve by use of high quality, efficiently produced, readily accessible mapping products for everyday applications.
GPS
Overview
The larger political jurisdictions of the world's most affluent countries, including many US counties and cities, have available to them high quality and cost-effective digital mapping products based on ever-improving satellite and computer technologies. However, technology transfer to the majority of the world's countries has been slow, leaving the vast majority of the world dependent on sub-standard and costly conventional surveying techniques. This is particularly true with Global Positioning System (GPS) technology transfer to most of Africa, Asia, South America and Eastern Europe. These areas are effectively left without the means to enjoy most of the benefits of GPS technology.
GPS work involves the reconnaissance, monumentation, observation and adjustment of dispersed points in order to calculate intervening locations and elevations of an object on the surface of the earth. This information can then be combined with features captured from aerial or by remote sensing satellite images to produce necessary scale accurate digital maps or Geographic Information System (GIS) basemaps.
GPS technology can now be used to provide millimeter level positional accuracy. However, the system requires control points of higher accuracy to achieve desired application accuracy. In North America and some European countries a High Accuracy Reference Network of known high order points has been established. These known points allow the collection of intermediate project-specific points to be both accurate and affordable. For a variety of reasons, investment in this type of network has been slow to come to most of the rest of the world. Thus, large populations of potential beneficiaries are unable to take advantage of accurate and affordable end-user GPS applications.
Selection and field location of the appropriate number of Global Positioning System (GPS) ground control points is critical to the successful development and implementation of user-specific applications. These ground control points form the backbone of subsequent mapping, engineering or Geographic Information System (GIS) projects and control the accuracy, geometry, authenticity, and, ultimately, determine the success or failure of these endeavors.
Only through academic research and applied practice does one gain the necessary expertise to optimize GPS applications, whether on a country-wide or project-specific basis. EMI has this experience.
Geographic Infromation Systems (GIS)
Overview
The use of data for broad public purposes has become a way of life for most of North America and Western Europe. Demographics of a national census can be verified for accuracy by comparison with known housing stock identifiable from aerial imagery. The transportation and utility systems in areas of known volcanic, earthquake, typhoon or hurricane vulnerability can be modeled to predict deficiencies in capacity during catastrophic events. Property ownership information can be integrated with historic utility billing, utility system as-builts and aerially obtained topography to identify areas of low water pressure and model optional solutions. Alternative investment patterns can be used to predict the impact on valuable croplands.
These analysis, planning and basic design tools have enriched the quality of life for only those fortunate few who live in areas which have the means to secure and utilize such tools. The rest of the world watches and waits. EMI's primary reason for being in business is to harness the technology of geomatics for improving quality of life.
Remote Sensing
Overview
Remote sensing is the science and art of deriving information about an object from measurements made at a distance, i.e., without actually coming in contact with it. Remote sensing data is captured using different platforms (airborne, satellite) and sensors (camera, MSS, CCD, etc.). Remote sensing data can include the entire spectrum of electromagnetic radiation (visible, infrared, thermal, microwave, radiowave, etc.) as compared to the photogrammetry, which uses only visible portion of the electromagnetic spectrum. In a vague term remote sensing can be recognized as a system that uses satellite platforms. The first remote sensing system was the Landsat program (Landsat 1-2-3-4-5-6-7). Currently, we are on the seventh generation of the Landsat program collecting terrestrial image data. There are many other government remote sensing programs including SPOT and IRS.
In the nineties, private satellite corporations started collecting high-resolution remote sensing data using polar orbiting satellites. Currently, Space Imaging's IKONOS satellites, and Orbimage's Orbview satellites acquire 1-meter (PAN) and 4.0 meter (MS) satellite images. There are a few governmental high-resolution remote sensing programs including the French SPOT and the Indian Remote Sensing (IRS) satellites, which collect data up to 2.5m resolution.
EMI's technical team believes that high-resolution satellite imagery will replace medium and small-scale mapping (e.g. USGS Quad Maps, DOQQs). To tap into this vast market, EMI is teaming up with the Satellite Corporation GeoEye, which will increase EMI's mapping capabilities for any size and scale throughout the world. EMI's team has been involved in processing and analysis of different types of the above-mentioned satellite data for various applications.
LiDAR
Light Detection and Ranging (LiDAR)
Light Detection and Ranging (LiDAR) consists of the following components: scanner, Airborne GPS, Inertial Measurement Unit, ground based GPS stations, known control points, computer to store the data and software to process the data. The biggest challenge with the LiDAR system would be to correlate the data from different sources to the same time stamp ( a difference of 1-nano second will cause 30 cm error in the data, speed of light ~300000000 meter/109 ).
Data processing and quality control procedures for all primary data collection are very stringent at EMI, since without the primary data no project can proceed further. However, to get the best possible quality data, personnel at EMI spend ample time in project planning and research. EMI provides strict guide lines to its sub-consultants and work closely with them until the data capture is completed successfully.
Collection of topographic data has been a very cumbersome and expensive part of mapping. With the advent of digital photogrammetry and LiDAR technology, topographic mapping at 1.0 FT contour intervals can be achieved within a fraction of cost and time. [Topographic data for engineering design and emergency forecasting, hydrologic modeling, storm water modeling are very critical in terms of its accuracy. Earth Mapping International has been using digital photogrammetry in conjunction with LiDAR data to produce 2.0' contour topographic mapping for engineering projects. Some samples of our work is shown on the reverse side]
The topographic data types and formats EMI provides are: 0.5-Foot Contour Mapping for GDOT, 2-Foot Contour Mapping for various engineering projects, 4-Foot Contour mapping for countywide mapping projects.
The data formats: 3_D AutoCAD dwg file, CaiCE 3_D file, Microstation dgn file, ASCII DTM file, ESRI shape file. EMI can provide the DEM/DTM data in any format as per the client request.
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