Blue tab
Green tab
Brown Tab

Earth Observation

 

 

Introduction

Wikipedia Definition of Earth Observation (http://en.wikipedia.org/wiki/Earth_observation)

Earth observation is the gathering of information about planet Earth's physical, chemical and biological systems. It is used to monitor and assess the status of, and changes in, the natural environment and the built environment. In recent years, Earth observation has become technologically more and more sophisticated. It has also become more important due to the dramatic impact that modern human civilization is having on the Earth, the need to minimize the negative impacts, and the opportunities Earth observation provides to improve social and economic well-being.

Earth observations can include:

• a birdwatcher's notes on bird sightings • numerical measurements taken by a thermometer, wind gauge, ocean buoy, altimeter or seismometer • photos and radar or sonar images taken from ground or ocean-based instruments • photos and radar images taken from remote-sensing satellites • decision-support tools based on processed information, such as maps and models

Just as Earth observations consist of a wide variety of possible elements, they can be applied to a wide variety of possible uses. Some of the specific applications of Earth observations include:

• forecasting weather
• tracking biodiversity and wildlife trends • measuring land-use change (such as deforestation) • monitoring and responding to natural disasters, including fires, floods, earthquakes and tsunamis • managing natural resources, such as energy, freshwater and agriculture • addressing emerging diseases and other health risks • predicting, adapting to and mitigating climate change

The quality and quantity of Earth observations continue to mount rapidly. In addition to the ongoing launch of new remote-sensing satellites, increasingly sophisticated in-situ instruments located on the ground, on balloons and airplanes, and in rivers, lakes and oceans, are generating increasingly comprehensive, near-real time observations.

Satellite and airborne EO data have been intensively used in the past for mineral exploration. Major mining companies used Landsat MSS, then TM as well as radar images to help finding mineralization and/or favourable structural models. Airborne and ground geophysics provided information on surface and subsurface data, along with deeper structures. Imaging spectroscopy started to be used in the 1980s.

At that time, little attention was paid to environmental and social concerns.

From late eighties and in the nineties several programmes started to foster the use of Earth Observation applied to environmental concerns. The Superfund programme in USA, led by US EPA and USGS (Superfund is the federal government's program to clean up the nation's uncontrolled hazardous waste sites) demonstrated the capabilities or EO methods, in particular Hyperspectral AVIRIS Imaging sensor in mapping hazardous wastes. Meanwhile, the development of the Hy-Map sensor in Australia and the involvement of CSIRO fostered the use of imaging spectroscopy in this domain.

In Europe, the PECOMINES project, using conventional satellite sensors and the FP5 MINEO project, using HyMap hyperspectral images were cornerstone projects focusing on miningrelated environmental concerns. None of these projects however made an integrated use of all available EO tools and techniques and lacked association of satellite, airborne and in situ monitoring technologies.

The use of remote sensing approach in the investigation of environmental impacts caused by mining to address issues like acid mine drainage (AMD), watershed pollution, subsidence and nowadays also the ecological footprint, replaces different methods used so far, like aerial photography and ground based data takes. Until recently, satellite imagery has lacked the spatial, temporal and radiometric resolution to compete especially at small scale and quantification of target materials. However, new satellite and airborne sensor systems offer new opportunities on the bias of data collected both in the optical part of the electromagnetic spectrum and in the microwave wavelength region. The increasing trend to comparable cheaper instrumentation and, therefore, lower costs per square kilometre encourages a thorough evaluation, the development of suitable models for data analysis, time series analysis and data assimilation techniques as well as the development of quality measures and quality standards.

To facilitate the acceptance of multispectral, hyperspectral and radar imagery, quality measures not only have to be defined. The general principles of current senor technologies and their relevant physical parameters, combined with the basics and principles of in collecting and processing data and corresponding quality aspects of the imagery itself have to be described in detail and the improvement have to be demonstrated and documented.

The defined quality measures, the demonstrated ability to improve data processing chains and the different data products are important aspects for the gained acceptance of remote sensing technologies in near future. Therefore, those documentations are one of the important outcomes of the project.