National Forest Monitoring Systems must consistently measure change over large areas at repeated intervals. The only practical solution is to employ remotely-sensed Earth observations.

This page presents resources that will help prospective users get started with Understanding, Accessing and Applying space-based Earth observations.


Role of Satellite Data in NFMS

National priorities and policy decisions will dictate the specifics of the activity data/maps needed for reporting purposes. Remotely-sensed EO data – together with the techniques presented in the GFOI Methods and Guidance Documentation – can be used to produce the following map products:

  • Forest/Non-forest and change maps
  • Forest stratification maps
  • Spatially explicit land-use categories
  • Land use changes between forests and other land uses
  • Maps of change within forest land
  • Near-real time forest change indicators
Relevant Data Types

High-resolution optical imagers provide detailed images of Earth’s surface. In general, these are nadir-viewing instruments with a horizontal spatial resolution in the range 10 m to 100 m and swath widths of order 100 km. High-resolution imagers are, in general, panchromatic (a single waveband) and multi-spectral (multiple waveband) sensors, with spectral bands in the visible and IR range that are simultaneously recorded.

Use of these sensors can be limited by weather conditions, since they are unable to penetrate thick cloud, rain or fog and are typically restricted to fair weather, daytime-only operation.


These instruments transmit at frequencies of around 1 GHz to 10 GHz and measure the backscattered signals to generate microwave images of Earth’s surface at high spatial resolutions (between 10 m and 100 m), with a swath width of 100–500 km. Both synthetic aperture radars and real aperture side-looking imaging radar systems fall into this category.

The images produced have a similar resolution to those from high-resolution optical imagers, but radars have the capability to ‘see’ through clouds, providing data on an all-weather, day/night basis.

SARs also have the ability to penetrate vegetation and to sample surface roughness and surface dielectric properties.

The CEOS Space Data Coordination Group for GFOI has worked with the world’s largest providers of Earth observation data to ensure that all countries have access to the satellite data required for national forest monitoring and reporting of greenhouse gas emissions and forest carbon stocks to the UNFCCC under the provisions of REDD+

Key Forest Monitoring Missions

GFOI’s global baseline data acquisition strategy involves coordination of a number of core data streams that satisfy key criteria consistent with the principles for implementation of the GFOI:

  • Core data streams provide data, at 30m resolution or finer, free-of-charge and openly shareable for GFOI purposes, consistent with being available in support of any country’s information requirements;
  • Core data stream systems have a sustained and long-term capacity in coverage, processing and distribution which is consistent with the large (global) scale data requirements of the GFOI.
Mission (instrument) Type Best Resolution Utility

Landsat-7 (ETM+)L7

Core – Optical 15m Forest/Non-Forest and Change, Forest Stratification (partial), Land-Use and Change between Forests and other Land Uses, Change within Forest Land (partial), Near-Real Time Forest Change Indicators (partial)

Landsat-8 (OLI/TIRS)L8

Core – Optical 15m Forest/Non-Forest and Change, Forest Stratification (partial), Land-Use and Change between Forests and other Land Uses, Change within Forest Land (partial), Near-Real Time Forest Change Indicators (partial)

Sentinel-1A/1B (C-band SAR)


Core – SAR 9m Forest/Non-Forest Change (partial), Land-Use (partial), Near-Real Time Forest Change Indicators

Sentinel-2A/2B (MSI)S2

Core – Optical 10m Forest/Non-Forest and Change, Forest Stratification (partial), Land-Use and Change between Forests and other Land Uses, Change within Forest Land (partial), Near-Real Time Forest Change Indicators


Regional Focus and Gap-filling 5m Forest/Non-Forest and Change, Forest Stratification (partial), Land-Use and Change between Forests and other Land Uses, Change within Forest Land (partial), Near-Real Time Forest Change Indicators (partial)

Core Datasets

Core data streams provide data at 30m resolution or finer, free-of-charge and openly shareable for GFOI purposes; and have sustained long-term capacity in coverage, processing and distribution.

Contributing Datasets

Other Public-Private Partnership (PPP) and commercial missions are also able to contribute to systematic national, regional, and global coverage.

Global Land Cover Maps and Annual Mosaics

Many global land cover maps have been available at various resolutions since the 1990’s, usually from 250 to 1000 metres, from sensors such as Envisat’s MERIS, Aqua/Terra’s MODIS, and NOAA’s AVHRR. While the resolution is too low to accurately map changes in forest area, such maps can serve as baselines and be used to identify areas that need to be monitored more closely.

More recently, agencies such as JAXA have released global annual mosaics at much higher resolutions (25-50 metres), which are sufficient for producing national forest/non-forest and change maps. Access information, including for the JAXA ALOS/PALSAR L-band SAR datasets, is presented below.

Access >>

Interpretation Guide for ALOS PALSAR / ALOS-2 PALSAR-2 Global 25 m Mosaic Data >>

Resources and More Information

Earth Observation Handbook

The CEOS Earth Observation Handbook presents the main capabilities of satellite Earth observations, their applications and a systematic overview of present and planned CEOS agency Earth observation satellite missions and their instruments.eohb_mim

Read >>

CEOS Mission, Instruments and Measurements Database

The CEOS Database is updated annually and is the only official consolidated statement of the programmes and plans of CEOS agencies. The contents cover 301 Earth observing satellite missions and 843 instruments (423 distinct) which are currently operating or planned for launch in the next 15 years – funded and operated by around 30 CEOS space agencies worldwide.

Explore >>


Core Data Portals
Landsat Data Access

Landsat Level 1 Data Products held in the USGS archives can be searched, ordered and downloaded on the following pages:

EarthExplorer: allows geographical searches of data held in the USGS archives.

Global Visualization Viewer (GloVis): a browser-based viewer for USGS Landsat archive datasets.

LandsatLook Viewer: a prototype tool that allows rapid online viewing and access to the USGS Landsat archive.

Sentinels Scientific Data Hub

The Sentinels Scientific Data Hub provides free and open access to a rolling repository of Sentinel-1 and Sentinel-2 user products, starting from the In-Orbit Commissioning Review (IOCR).

Copernicus Australia

Copernicus Australia is a regional hub, providing free and open access to data from Europe’s Sentinel satellite missions for the South-East Asia and South Pacific region.

Global Maps and Annual Mosaics
Global ALOS Mosaics and Forest/Non-forest Maps

The Japan Aerospace Exploration Agency (JAXA) has developed global SAR mosaics and Forest/Non-forest maps at 25-meter resolution using the ALOS-2 satellite, and has released these datasets for free via their website. Four-year, 25m global ALOS PALSAR mosaics (using data collected from 2007 to 2010), a 10m resolution global Forest/Non-forest map, and a low-resolution “FNF100” 100m resolution Forest/Non-Forest map have also been released.

JAXA has released these products for free in order to promote the use of L-band SAR for forest monitoring applications. JAXA plans to provide annual global Forest/Non-forest maps generated using ALOS-2 to help the community better understand forest distribution.

Special Datasets
CNES SPOT World Heritage (SWH) Data

Through the SWH programme, CNES offers access to ortho-rectified SPOT-1 through 5 data that were captured more than 5 years ago (rolling limit) for non-commercial uses. All data available from the SWH archive, operated by CNES, are free of charge.

More Information >>

Data Access >>

French Initiative for the Congo Basin

In December 2009, France committed to making Spot 4, 5, 6 and 7 satellite images available to the countries that make up the Congo basin. These images, acquired between 2010 and 2015, will be accompanied by images from the SPOT archive, dating from around the year 2000.

More Information >>

Data Access >>

ESA Sentinel Toolboxes

ESA is developing free, open source toolboxes for the scientific exploitation of the Sentinel missions. The toolboxes inherit functionality of historical toolboxes developed over the last 10 years and also support a range of third party missions. The toolboxes have been conceived to host new functionalities developed by the scientific community in the future.

More Information >>


The CEOS Visualization Environment (COVE) is a suite of tools for analyzing satellite sensor coverage for more than 100 Earth observing satellites. The COVE suite was developed by the NASA CEOS System Engineering Office (SEO) and all tools in the suite are publicly-available and free to use.

More Information >>


The Space Data Coordination Group (SDCG) for GFOI is charged with planning and coordinating the acquisition strategies required to support the needs of GFOI and its participating countries, and can answer any questions that you might have about space data.


Methods and Guidance Documentation

GFOI has developed a set of methods and guidelines for estimating future carbon stocks to support countries in their effort to build national forest monitoring systems. These methods and guidelines help ensure that forest carbon assessments are credible, comparable and transparent.

The MGD provides recommendations on establishing national measurement, reporting and verification (MRV) systems consistent with IPCC guidance and UNFCCC requirements for REDD+ reporting.

More Information >>

MGD Portal >>

Capacity Building Resources

SilvaCarbon and FAO are the Co-Leads responsible for the Capacity Building component of GFOI.


SilvaCarbon works in collaboration with its partners to deliver country-specific training in the selection, assessment, use and combination of different types of data for forest and carbon accounting. SilvaCarbon also hosts global and regional workshops/training courses on selected issues.

SilvaCarbon Website >>

GFOI & SilvaCarbon >>


FAO assists countries in developing national forest monitoring systems and assessments with the objective of providing reliable forest resource information for national forest policy development, planning and sustainable management.

FAO/UN-REDD Resources >>

GOFC-GOLD / World Bank FCPF Training Materials

The GOFC-GOLD / World Bank FCPF training materials for REDD+ monitoring and reporting have been compiled to respond to the need for technical assistance and guidance for countries to develop capacities and implement REDD+ monitoring and reporting.

This series of independently reviewed lectures and reference materials are based on the GOFC-GOLD Sourcebook and provide a set of modular training materials that can be used in combination with complementary guidance documents.

More Information >>

GOFC-GOLD Sourcebook >>

World Bank FCPF Documents >>