Abstract
The first human footprints dated more than 1.9 million years ago; the Homo erectus era, “upright man,” marks the beginning of man's socio-economic historical development. It culminated in the Bronze Age, Iron Age, Industrial Revolution, and currently the Information Age. The current era has allowed rapid global communications and networking to shape modern society. Individuals are able to transfer information freely, with instant access to knowledge that would have been difficult or impossible previously. This chapter elaborates upon GIS/remote sensing: the highest echelon in ICT. It compares and contrasts the four globally used GIS systems of GOES, the Geosynchronous Orbiting Environmental Satellite; LANDSAT; SPOT, Satellite Pour l'Observation de la Terre; and the WorldView. Their temporal resolution, spatial resolution, spectral resolution, radiometric resolution, and their DEM characteristics are reviewed. The human side of information reference services in the form of TEK is alluded to.
TopIntroduction
Ever since the first human footprints were made more than 1, 9 million years ago; the Homo erectus Era; ‘upright man’; socio-economic-Historical Development came into being. When humans could walk; it left their other limbs, the hands free to do other things. This Era was followed by the Stone Age; the man used stone tools to defend their territories and to hunt for food. This culminated to the Bronze Age and the Iron Age. These were the human development eras when man could actually work with minerals to make tools. These people could farm and rear domestic animals. The primitive smelting industries grew into the Industrial Revolution; The Industrial Revolution was a period from the 18th to the 19th century. The major changes in agriculture, manufacturing, mining, transport, technologies had a profound effect on the socio-economic and cultural conditions. This was followed by the Information Age; the Era we are in now. It is a shift from traditional industry that the previous era brought through industrialization. It is an economy based on the manipulation of information. The Information Age has allowed rapid global communications and networking to shape modern society. It is a digital world of Information Communication Technology (ICT). It is also commonly known as the Computer Age or Information Era, and it is an idea that the current age will be characterized by the ability of individuals to transfer information freely, and to have instant access to knowledge that would have been difficult or impossible to find previously. The idea is linked to the concept of a Digital Age or Digital Revolution. This chapter elaborates upon Geographical Information Systems (GIS) and Remote Sensing; the highest echelon of the ICT world. It looks at their development in studying our home, the Earth and its systems. In particular it looks at, compares and contrasts the four globally used systems; these are:
The first three has transacted five generation and the last system, the WorldView is the newest and most fast developing satellite system. These Earth Resources Data capture satellite systems are compared in their longevity - temporal resolution and age factor which gives results as:
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LANDSAT1 (ARTS 1) - LANDSAT 8 range July 1972 to February 1913;
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GOES 1 - GOES 15, Range October 1975 to March 2010;
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SPOT1 – SPOT 7 range February 1986 to June 2014 and
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WorldView 1 – WorldView 3, range September 2007 to August 2014.
The comparison criteria were made based on spectral resolution (Figure 5 – WorldView 3); spatial resolution (Figure 6 – WorldView 3) and radiometric resolution (Figure 7 – SPOT). Apart from that; the human side of information reference services in the form of Traditional Ecological Knowledge (TEK) is discussed as it is an essential complementary entity in GIS and remote sensing endeavours. In order to be useful information, the remote sensing data need human input in the form of referencing coordinates system, data interpretation using the visual variables of position, shape, size, texture, tone, orientation, and motion. These can then be analyzed and used for modeling the environment, disaster preparedness and decision making. The 3 Dimensional characteristics of satellite, digital elevation models (DEM) (Figure 7 – SPOT DEM) are also investigated.
The Chapter is also about the essence of data sources specific for geo-spatial science (Bossler, Jensen, McMaster, & Rizos, 2002) information for land cover mapping. The use of geospatial science techniques provides opportunities and challenges in many aspects of life including for land cover, forestry for climatic change measurements and agricultural engineering which is vital for food security (Opara, 2003)
Key Terms in this Chapter
Geographical Information Systems (GIS): Geographical Information Systems (GIS) is defined as a technique which people employ using computers and specific computer software and hardware to locate physical features and describe their characteristics and condition on a raster based or vector co-ordinate based digital map by interrogating attribute data and to engage in spatial analysis, and this is a sound basis for informed decision making (Burrough & McDonnell, 1998 AU43: The in-text citation "Burrough & McDonnell, 1998" is not in the reference list. Please correct the citation, add the reference to the list, or delete the citation. ).
Spectral Resolution: Different classes of features and details in an image can often be distinguished by comparing their responses over distinct electromagnetic wavelength ranges. Spectral resolution describes the ability of a sensor to define fine wavelength intervals.
Reconstruction of Historical Landscape (ROHL): Reconstruction of historical landscapes is defined as a method of building and mapping past landscapes by finding out how communities lived in a given historic period in a particular geographical area. This is achieved by identifying, reading and analysing marks made at the time and left behind from certain period. A historical landscape basically depicts a type of cultural landscape that contains, within a specific geographical area, both natural and human-made features that typify connected human activities, past events or patterns of physical development ( Maphanyane, 2012 ).
Geo Spatial Science (GSS): Geospatial Science is a discipline that focuses on using information technology to understand people, places, and processes of the earth. Spatial analysis of human and physically variables is fundamental to the discipline. Remote Sensing, Geographic Information Systems, and Global Positioning Systems technologies are commonly used as measurement, observation, and analysis tools for this (Radford University, 2014 AU44: The in-text citation "Radford University, 2014" is not in the reference list. Please correct the citation, add the reference to the list, or delete the citation. ).
Sensor: Sensors are devices that functions like a human eye. They detect the reflected or emitted electromagnetic radiation from natural sources (Passive Remote Sensing) or detect responses from objects which are irradiated from artificially generated energy sources such as radar (Active Sensors).
Spatial Resolution: Spatial Resolution, Pixel Size, and Scale. With remote sensing instruments, the distance between the target being imaged and the platform, plays a large role in determining the detail of information obtained and the total area imaged by the sensor.
Remote Sensing: Remote Sensing is the art, science, and technology of obtaining reliable information about physical objects and the environment through the processes of recording, measuring, and interpreting photographic images and patterns of electromagnetic radiant energy and other phenomena ( Lillesand & Kiefer, 2004 ).
Geo-Synchronized and Sun-Synchronous: The platforms are designed to follow a north-south orbit and in conjunction with the Earth’s west-east rotation, they are able to capture the entire Earth’s surface over a certain period of time. These satellite platforms orbits are often sun-synchronous: - They are able to cover each particular area on the Earth’s surface at a constant local time of day. This ensures consistent illumination conditions for images of the same area that have been acquired at different times.
Traditional Ecological Knowledge (TEK): The traditional ecological knowledge as a cumulate body of knowledge and beliefs, handed down through generations by cultural transmission, about the relationship of living beings with one another and with their environment. These are gained through the teaching of family history and cultural values. They have been recorded for thousands of years by storytelling, praise-singing, and songs as oral history, and are passed on to and learned by the descendants through the recitation of the narrative at events and during ceremonies ( Berkes, Colding, & Folke, 2000 ).
Panchromatic: Black and white aerial photograph or satellite images.
Classification: The process of classification identified and assigned each pixel of all channels of the multi-spectral images to a particular class or theme based on the statistical characteristics of the pixel brightness values known as spectral signatures.
Land Cover Change: Land cover change forms a fundamental part of sustainable resource management. It is actually the main indicator of natural resource use.
Archaeology: The importance of archaeology lies in the fact that it seeks to learn about culture from the fragmentary remains of the products of human activity (Deetz, 1992 AU42: The in-text citation "Deetz, 1992" is not in the reference list. Please correct the citation, add the reference to the list, or delete the citation. ).
Temporal Resolution: Temporal resolution: Other than: Spatial, Spectral and radiometric resolution; there is temporal resolution. This is the time it takes to image the exact same area at the same viewing angle a second time: Revisit Time.
Geo-Stationary: Geostationary satellite Platforms are platforms that revolve at speeds which match the rotation of the Earth so they seem stationary, relative to the Earth's surface. This allows the satellites to observe and collect information continuously over specific areas.
Biostratigraphic Markers: Biostratigraphy is a sub-discipline of sedimentary geology that relies on the physical zonation of biota, both in time and space, in order to establish the relative stratigraphic position (i.e. older, younger, same age) of sedimentary rocks between different geographic localities.
Electromagnetic Waves Energy: The electromagnetic (EM) spectrum describes the range of wavelengths of energy that can be recorded using remote sensing and It can be broadly divided (by increasing wavelength) into Gamma rays, X-rays, Ultra-violet light, Visible light, Infrared light, Microwave and Radio waves.
Platform: In order for the sensor to capture and record reflected or emitted energy from a target it must reside on a stable platform which can be on the ground (hand held camera), within the atmosphere (airplanes), and in space (the space shuttle or satellite).
Multi-Spectral: A multispectral image is one that captures image data at specific frequencies across the electromagnetic spectrum, the visible light range, and infrared. Spectral imaging sees beyond what human eye can perceive.
Radiometric Resolution: The radiometric resolution of an imaging system describes its ability to discriminate very slight differences in energy.