This report, prepared for the UN Economic Commission for Africa, reviews the status and prospects for remote sensing in Africa.

The authors argue that a real and immediate need exists for real-time remote sensing data to improve early warning, vulnerability assessment, mitigation, response and relief of disasters. This means, they say, supporting African countries to acquire data — including launching their own satellites, as well as improving bandwidth infrastructure and building capacity for analysing and processing geoinformation.

The authors highlight the continent's limited connectivity as a particularly challenging hurdle to overcome, as well as a lack of training and expertise in remote sensing. They briefly outline international donors' efforts to improve the situation and suggest improving collaboration and networking.

This article describes how a network of sensors, linked by software and the Internet, can provide an automatic satellite-based surveillance system for disasters such as volcanoes, wildfires and flooding.

The system, or 'Sensorweb', uses data from low resolution, high frequency sensors to trigger imagery from high resolution instruments. The low-resolution data is collected regularly (twice a day or more) from instruments such as NASA's Moderate Resolution Imaging Spectroradiometer (MODIS).

Anomalies, such as hotspots in the case of fires and volcanoes or surface water for floods, are automatically detected. The SensorWeb then sends a request to a higher resolution satellite such as Hyperion, which is very sensitive in the infrared spectrum, to request data over the area of interest. These data can then provide disaster managers with early warnings of adverse events.

This feature article, written by members of the UN Operational Satellite Applications (UNOSAT) programme, outlines how satellite technology can improve emergency relief after a natural disaster.

UNOSAT uses satellite data to produce maps and damage reports for nongovernment organisations, intergovernmental agencies and disaster managers in emergency situations. The authors describe how the process works — from receiving a relief agency's phone call to collecting and analysing relevant satellite data.

They argue that satellite data, when combined with ancillary data such as road maps or population distribution, can help aid workers navigate affected areas and provide estimates of the number of people likely to be affected by, for example, floods or landslides.

The authors describe the range of satellite sensors used by UNOSAT, explaining the advantages of different types of data depending on the disaster. For example, radar imagery, which is unaffected by cloud, is particularly useful to monitor flooding, whereas high resolution optical data is better for earthquake damage assessment.

Written by former director of India's National Remote Sensing Agency, D. P. Rao, this article reviews the role of space technology in disaster mitigation.

Rao offers examples of how remote sensing can feed into prevention, preparedness and relief strategies for a number of disasters. He identifies the areas where these applications are operational, and those that need more research and development.

For drought, cyclones, floods, fires, earthquakes and other disasters in India, Rao outlines the status of relevant remote sensing projects. He outlines the extent of the problem posed by each disaster, and how Indian government and nongovernment organisations use remote sensing to improve risk assessment and early warning.

This report, written by solid-Earth scientists at NASA's Jet Propulsion Laboratory, sets out the requirements for delivering high-accuracy, high-resolution surface deformation data for earthquake studies.

The authors build on recommendations made by NASA's Solid Earth Science Working Group. They propose a constellation of satellites for interferometric synthetic aperture radar (InSAR) — a technique based on combining two or more radar images in a way that can measure ground motion on a centimetre scale.

A constellation of InSAR satellites could provide earthquake prediction data, suggest the authors. The GESS report defines a 20-year roadmap for earthquake forecasting and outlines the measurement requirements, as defined by scientists and disaster managers.

This article, written by Chris Funk of the US GS, outlines how the Famine Early Warning Systems Network (FEWS NET) uses satellite data and statistical forecasts to provide early warnings of potential droughts in sub-Saharan Africa.

Funk outlines the role of satellite data in FEWS NET at all stages of the crop-growing season — from scenario building before the season to calculating the water balance during it and assessing yields at the end. Focusing on food security outlooks for East Africa in late 2008, Funk describes how data from NASA's Aqua and QuikSCAT satellites can be used to track moisture and wind conditions over the Indian Ocean and Africa, and how these help anticipate hydrologic conditions in the future to predict shortfalls.

Funk emphasises the need to combine such data with socio-economic analyses of, for example, crop prices, grain stores, political conditions and agricultural inputs. This will help maximise the accuracy and effectiveness of early warnings of drought and food shortages.

This report, prepared by the Committee on Earth Observation Satellites (CEOS), presents the main capabilities of satellite systems and their applications to detect, monitor and adapt to climate change, alongside plans for future relevant satellite missions.

The report is divided into three parts. The first discusses the Earth's changing climate, emphasising the role of satellite imagery in monitoring this. The second presents a number of case studies to illustrate how earth observing satellites provide data to improve our understanding of climate change, including charting sea-level rise to better cope with flooding.

The final part summarises satellite capabilities with a description of the different satellite missions and instruments as well as their applications, such as to improve weather forecasting or provide damage assessment associated with natural disasters.

This review article describes how remote sensing data can and are being used to map and monitor disasters such as earthquakes, volcanic eruptions, landslides, flooding and wildfire.

The authors summarise the main satellites and sensors used in disaster monitoring and their characteristics. They also discuss in more detail the data and techniques used for individual types of disaster, outlining the advantages and drawbacks to each. In particular, they describe the methods most commonly used to analyse optical, thermal, radar and LiDAR (Light Detection and Ranging) data.

The authors summarise ongoing initiatives using remote sensing data for disaster management, including Sentinel Asia and the International Charter on Space and Major Disasters. Potentially useful emerging systems such as the Disaster Monitoring Constellation are briefly discussed.