The field of earth observation experienced a revolutionary change when the US launched the Earth Resources Technology Satellite (ERTS), later renamed Landsat on 23 July 1972.
Former USSR launched the first artificial satellite, Sputnik-1, on 4 October 1957 and later, the US operated a series of satellites called Corona between 1959 and 1972. However, these were used exclusively for military use. ERTS became the first satellites for civilian use. So far, NASA has placed nine Landsat series satellites into orbit.
Over time, technology has seen tremendous changes like the introduction of powerful instruments, data capture methods and data analysis processes. Soon many other countries lined up to launch their own earth resources satellites, viz; SPOT of France (1986), IRS of India (1988), and now the list includes the US, China, Russia, the UK, Japan, member countries of the European Space Agency, Canada, Germany, Luxemburg, etc.
The launch of the earth resources satellite ie Landsat, is the beginning of the commercialisation of remote sensing technology. Currently, both government and non-government organisations like Ikonos, Quickbird, Orbview and Rapideye are working with satellite technology.
With the development of technology (increase of spatial resolution from 80m to less than a metre, expansion of spectral resolution from four bands to hundreds of bands), easy availability of image data (multi-temporal as well), an increase in data processing and analytical capabilities, globally the utilisation of satellite data expanded remarkably.
It is noteworthy that satellites are used not only for earth observation purposes but also for telecommunication, TV transmission, meteorology etc. However, in this article, the focus is concentrated only on earth resource satellites.
During the early days, satellite images were used for geological and geomorphological mapping, mineral and hydrocarbon explorations, agriculture and forestry, land cover and mapping, soil mapping, water resources, wetland mapping, urban and regional planning, ecology, environmental assessment, natural hazard assessment, etc.
But over time, areas of applications have grown tremendously like climate change analysis (glacial retreat, sea level rise, extreme storm, extreme heat, drought), evaluation of the impact of man-made structures on the environment, measuring surface temperature to map heat risk in the urban areas aiming to predict heat wave conditions, monitoring dying wetland and mangrove forests in hard-to-reach regions, monitoring the detrimental effects of saline water intrusion in the coastal environment due to sea level rise.
It is inspiring to know that from the beginning of the Landsat Programme, scientists and geologists of Bangladesh showed interest and started working. Initially, concentration was towards the coastal area to study the accretion and erosion processes.
However, during the last 50 years, satellite data has expanded to geological mapping, river morphology and river-course changes, agriculture, forestry, fisheries, wetland mapping, geoarchaeology and natural hazards (especially cyclones and floods), etc.
Besides those, disaster management, climate change (heat wave, precipitation, atmospheric anomaly and aerosol etc.), air pollutants, public health (environmental factors in air-borne, vector-borne, soil-borne, and water-borne diseases), ocean study and marine resources, coastal zone management, monitoring of sea level rise, land cover and use monitoring, food security, geo-archaeology and archaeology (landscape, conservation and heritage management), etc could be other potential fields.
Bangladesh is unique in terms of its geographic, geologic and tectonic settings that house a huge population under the threat of climate change. This technology has immense potential to provide a better and safe life for our people with sustainable use of its limited earth resources.
Moreover, we must give importance to education, research, and the creation of a skilled workforce, so that they can cope with this rapidly advancing technology to meet ever-increasing needs for better monitoring, understanding and prediction, leading to decision making.
Dr A K M Khorshed Alam is a Remote Sensing Geologist and Researcher
Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinions and views of The Business Standard.