Bi-spectral InfraRed Detection Research Articles

The Capabilities of Dedicated Small Satellite Infrared Missions for the Quantitative Characterization of Wildfires.

The main objective of this paper was to demonstrate the capability of dedicated small satellite infrared sensors with cooled quantum detectors, such as those successfully utilized three times in Germany’s pioneering BIRD and FireBIRD small satellite infrared missions, in the quantitative characterization of high-temperature events such as wildfires. The Bi-spectral Infrared Detection (BIRD) mission was launched in October 2001. The space segment of FireBIRD consists of the small satellites Technologie Erprobungs-Träger (TET-1), launched in July 2012, and Bi-spectral InfraRed Optical System (BIROS), launched in June 2016. These missions also significantly improved the scientific understanding of space-borne fire monitoring with regard to climate change. The selected examples compare the evaluation of quantitative characteristics using data from BIRD or FireBIRD and from the operational polar orbiting IR sensor systems MODIS, SLSTR and VIIRS. Data from the geostationary satellite “Himawari-8” were compared with FireBIRD data, obtained simultaneously. The geostationary Meteosat Third Generation-Imager (MTG-I) is foreseen to be launched at the end of 2022. In its application to fire, the MTG-I’s Flexible Combined Imager (FCI) will provide related spectral bands at ground sampling distances (GSD) of 3.8 µm and 10.5 µm at the sub-satellite point (SSP) of 1 km or 2 km, depending on the used FCI imaging mode. BIRD wildfire data, obtained over Africa and Portugal, were used to simulate the fire detection and monitoring capability of MTG-I/FCI. A new quality of fire monitoring is predicted, if the 1 km resolution wildfire data from MTG-1/FCI are used together with the co-located fire data acquired by the polar orbiting Visible Infrared Imaging Radiometer Suite (VIIRS), and possibly prospective FireBIRD-type compact IR sensors flying on several small satellites in various low Earth orbits (LEOs).

Small Satellite Tools for High-Resolution Infrared Fire Monitoring.

Space-borne infrared remote sensing specifically for the detection and characterization of fires has a long history in the DLR Institute of Optical Sensor Systems. In the year 2001, the first DLR experimental satellite, Bi-spectral Infrared Detection (BIRD), was launched after an intensive test period with cooled IR sensor systems on airborne systems. The main basis for the development of the FireBIRD mission with the two satellites, Technology Erprobungsträger No 1 (TET-1) and Bi-spectral-Infrared Optical System (BIROS), was the already space-proven sensor and satellite technology with successfully tested algorithms for fire detection and quantification in the form of the so-called fire radiation power (FRP). This paper summarizes the development principles for the IR sensor system of FireBIRD and the most critical design elements of the TET-1 and BIROS satellites, especially concerning the attitude control system—all very essential tools for high-resolution infrared fire monitoring. Key innovative tools necessary to increase the agility of small IR satellites are discussed.

Fire detection and monitoring using MSG Spinning Enhanced Visible and Infrared Imager (SEVIRI) data

Detection and parameterization of forest fires is a task traditionally performed by polar‐orbiting sensors, mainly advanced very high resolution radiometer (AVHRR) advanced along track scanning radiometer (AATSR), bispectral infrared detection (BIRD), and Moderate Resolution Imaging Spectroradiometer (MODIS). However, their time resolution is a problem to operate in real time. New geostationary sensors have proven their capacity for Earth observation. GOES, MSG, and MTSAT are already operative with time resolutions below 30 min. The international community feels that a real‐time global observation network may become a reality, which is the aim of the Global Observations of Forest Cover and Land Cover Dynamics (GOFC/GOLD) FIRE Mapping and Monitoring program, focusing internationally on decision‐making concerning research into global change. This paper shows the operation in real time by the MSG SEVIRI sensor over the Iberian Peninsula. For fire detection, a temporal gradient of temperature 3.9 μm is used, which is more efficient at eliminating incoming false alarms from solar reflection. Capacity to detect hot forest fires below 0.3 ha in Mediterranean latitudes has been analyzed along with the conditions in which it is possible to apply the MODIS methodology to establish the fire radiative energy (FRE) by means of experimental relation. We found that in this case, fire size can introduce maximum differences of 40% in FRE for small‐scale fires. The capacity of this sensor is shown in different cases that have greatly impacted Spain and Portugal because of the loss of human life.

Spaceborne detection and characterization of fires during the bi-spectral infrared detection (BIRD) experimental small satellite mission (2001–2004)

Wildfires have a range of significant environmental effects with respect to both Earth's surface and atmosphere. Spaceborne remote sensing of active fires has been undertaken for more than two decades, but the bi-spectral Infrared Detection (BIRD) Experimental Small Satellite (2001–04) is the first mission dedicated to this task. This paper summarizes the experience gained during the BIRD mission, which has focused both on active fire detection and active fire characterization, in terms of quantifying effective fire temperature ( T F), effective fire area ( A F) and fire radiative power (FRP). A detailed error analysis for each parameter is undertaken, and the accuracy of FRP retrieval is shown to be significantly better than that of T F or A F. For key fire-affected forest, bush and savanna environments (Australia, Benin, Borneo, Brazil, Canada-US, Portugal and Siberia) BIRD data allows FRP estimation to within 30% in 75% of fires examined, and for the first time from space BIRD is able to allow estimation of fireline length, effective fireline depth and radiative fireline intensity for the more pronounced fire fronts. Some indication of the predominant combustion regime (smoldering or flaming), which has implications for the relative concentrations of emitted pollutant products, is possible through use of the T F parameter. This experience demonstrates the advantages of the new infrared sensor technologies employed in BIRD, and offers suggestions for future fire monitoring sensors based on similar technologies.

Technology demonstration by the BIRD-mission

Small satellites have to meet a big challenge: to answer high-performance requirements by means of small equipment and especially of small budgets. Out of all aspects the cost aspect is one of the most important driver for small satellite missions. To keep the costs within the low-budget frame (in comparison to big missions) the demonstration of new and not space-qualified technologies for the spacecraft is one key point in fulfilling high-performance mission requirements. Taking this into account the German DLR micro-satellite mission BIRD (Bi-spectral Infra-Red Detection) has to demonstrate a high-performance capability of spacecraft bus by using and testing new technologies basing on a mixed parts and components qualification level. The basic approach for accomplishing high-performance capability for scientific mission objectives under low-budget constraints is characterized by using • state-of-the-art technologies, • a mixed strategy in the definition of the quality level of the EEE parts and components, • a tailored quality management system according to ISO 9000 and ECSS, • a risk management system, • extensive redundancy strategies, • extensive tests especially on system level, • large designs margins (over-design), • robust design principles. The BIRD-mission is dedicated to the remote sensing of hot spot events like vegetation fires, coal seam fires or active volcanoes from space and to the space demonstration of new technologies. For these objectives a lot of new small satellite technologies and a new generation of cooled infrared array sensors suitable for small satellite missions are developed to fulfil the high scientific requirements of the mission. Some basic features of the BIRD spacecraft bus are • compact micro satellite structure with high mechanical stability and stiffness, • envelope qualification for several launchers, • cubic shape in launch configuration with dimensions of about 620 × 620 × 550 mm 3 and variable launcher interface, • mass ratio bus:payload = 62 kg:30 kg, • high peak power of 200 W at 10–20 min, and average power 60 W, • advanced thermal control system with radiators, heat pipes, MLI, temperature sensors and contingency heaters, • new developed high-performance spacecraft bus computer with integrated latch-up protection and error detection and correction system, • three-axis stabilization of the spacecraft by an attitude control system in state space representation, • integrating the payload platform with its structure, thermal and power requirements, • onboard determination of the spacecraft position and velocity by the onboard navigation system basing on receiving and onboard processing of GPS data, • S-band communication with high bit rate (2.2 Mbps) and low bit rate. The total mass of the complete spacecraft is 92 kg. BIRD shall demonstrate the limits and the advantages of using new developed components, methods, algorithms and technologies. The satellite was launched with the Indian PSLV-C3 from Shar on 22nd October 2001 into an Sun-synchronous circular orbit of an altitude of about 568 km. (The paper describes the new developed technologies like onboard navigation system, the high-performance failure tolerant spacecraft computer, the precision reaction wheels, the star sensor, the attitude control system, the onboard classification experiment and the results and flight experience up to now.)

EKOSAT-IR-Ecology-related earth observation and hot spot detection

The initial EKOSAT (ELOP-KARI-OHB-Satellite) mission, planned to be launched as in-orbit demonstrator of the Multi-Spectral Remote-sensing System (MSRS), is enhanced by the space-proven Hot-Spot-Recognition System (HSRS) from DLR. HSRS is currently demonstrating its advanced High-Temperature Event detection and analysis capabilities on the German Bi-spectral InfraRed Detection (BIRD) satellite. MSRS, developed by OHB and ELOP, provides high-resolution super-spectral data (VIS/NIR) for ecological applications. Joint operation of MSRS and HSRS will deliver for the first time simultaneously high-resolution super spectral and hot-spot data of hazard events. A feasibility study based on the existing KOMPSAT-1 flight spare model from KARI as spacecraft bus shows that EKOSAT-IR will facilitate a fast in-orbit deployment of MSRS and HSRS at a comparably low-cost. Based mainly on existing ground infrastructure, EKOSAT-IR will demonstrate and deliver new super-spectral and infrared Earth observation products for Earth Watch and GMES objectives as well as for upcoming commercial markets.

Detection and analysis of high-temperature events in the BIRD mission

The primary mission objective of a new small Bi-spectral InfraRed Detection (BIRD) satellite is detection and quantitative analysis of high-temperature events like fires and volcanoes. An absence of saturation in the BIRD infrared channels makes it possible to improve false alarm rejection as well as to retrieve quantitative characteristics of hot targets, including their effective fire temperature, area and the radiative energy release. Examples are given of detection and analysis of wild and coal seam fires, of volcanic activity as well as of oil fires in Iraq. The smallest fires detected by BIRD, which were verified on ground, had an area of 12 m 2 at daytime and 4 m 2 at night.

Peat fires detected by the BIRD satellite

Tropical peat swamp forests store huge amounts of carbon, which is released to the atmosphere as carbon dioxide during fires. Recurrent peat swamp forest fires are local catastrophic events that can have a serious impact on the global carbon balance. Urgent tasks in this regard are the provision of information on the fire locations and magnitude of the carbon emissions. The experimental Bi-spectral InfraRed Detection (BIRD) satellite enables early detection of peat swamp forest fires and retrieval of their quantitative characteristics, such as the effective fire temperature, area and radiative energy release. The combination of ground truth measurements and data obtained by BIRD can improve the accuracy of estimates of carbon emissions into the atmosphere and related trace gas composition.

Real-Time Natural Disasters Detection and Monitoring from Smart Earth Observation Satellite

Current remote sensing satellites with multispectral sensors capture high-resolution images and produce vast quantities of data. The size and volume of this information has dramatically increased in the last decade as sensor resolution and capabilities have significantly improved, without a similar improvement on the satellite system capacity to accommodate these changes. Remote sensing satellites currently operate on a “store and forward” paradigm, where data is stored on the satellite until the satellite is in view of the ground station. Low Earth orbit satellites may only see a ground station for a 10–15 min window per pass, in which time all the collected information must be telemetered to the ground. This process requires large and expensive onboard storage resources and places tremendous stress on communication channels. Hence, a complete image may not be successfully telemetered in one pass causing a significant delay between capture and analysis and limiting the benefits of these images. Smart satellites are more technologically advanced, require less ground station support and data storage, and are capable of transmitting required information quickly and easily to ground stations. With onboard reconfigurable data processing, these satellites have faster data product turnaround, less communication requirements, and provide more useful information. The high performance computing (HPC-I) payload on board the Australian satellite FedSat, launched in December 2002, is a demonstration device of the feasibility of reconfigurable computing technology in space. This device is small in size, requires low power, and has the processing capacity to handle large data volumes. Using this device in conjunction with a high-resolution imaging sensor, such as the bispectral infrared detection (BIRD) sensor, smart dedicated satellites become a feasible and cost effective solution to remote sensing needs. This paper elaborates on the system level design of a real-time fire observation system in the context of a smart satellite mission for detecting and monitoring natural disasters. The proposed system is built upon flight tested field programmable gate arrays based HPC-I technology, and would be capable of producing useful information about natural disasters directly broadcasted to interested parties within rapid timeframes. The algorithms for onboard real-time detection of direction, intensity, and location of fires are discussed, and reliable algorithms for detecting and verifying these fires using smoke plume detection are presented. Further work is described including fire-front analysis and the tracking of fire movement.

Fire radiative energy for quantitative study of biomass burning: derivation from the BIRD experimental satellite and comparison to MODIS fire products

A major focus in global change research is to quantify the amount of gaseous and particulate pollutants emitted from terrestrial vegetation fires. Determination of the emitted radiant energy released during biomass combustion episodes (the so-called fire radiative energy or FRE) has been suggested as a new tool for determining variations in biomass combustion rates and the rate of production of atmospheric pollutants. We review the physical principals behind the remote determination of FRE and present an alternative method for its derivation via analysis of ‘fire pixel’ radiances in the middle infrared spectral region. We compare our method to the existing FRE retrieval approach used in the EOS Moderate Resolution Imaging Spectro-radiometer (MODIS) fire products, and to retrievals of FRE based on derived fire temperature and area made via the so-called Bi-spectral method. We test each FRE retrieval method using both simulated data and imagery from a new experimental space mission, the Bi-spectral InfraRed Detection (BIRD) small satellite, which has sensors specifically designed for the study of active fires. We analyse near simultaneous MODIS and BIRD data of the fires that burned around Sydney, Australia in January 2002. Despite the markedly different pixel size and spectral coverage of these sensors, where the spatial extent of the fire pixel groups detected by MODIS and BIRD are similar, the derived values of FRE for these fires agree to within ±15 %. However, in certain fires, the lower spatial resolution of MODIS appears to prevent many of the less intensely radiating fire pixels being detected as such, meaning MODIS underestimates FRE for these fires by up to 46% in comparison to BIRD. Though the FRE release of each of these low intensity fire pixels is relatively low, their comparatively large number makes their overall FRE significant. Thus, total FRE release of the Sydney fires on 5 January 2002 is estimated to be 6.5×10 9 J s −1 via BIRD but 4.0×10 9 J s −1 via MODIS. The ability of BIRD to resolve individual fire fronts further allows the first accurate calculation of ‘radiative’ fireline intensity from spaceborne measurements, providing values of 15–75 kJ s −1 m −1 for fire fronts that are up to 9 km in length. Finally, we analyse the effectiveness of the satellite-based FRE retrieval methods in estimating the FRE from the active flaming and smouldering components only (FRE Active, believed to be proportional to the rate of biomass combustion), despite the sensor receiving additional radiance from the ‘cooling ground’. The MIR radiance method appears particularly strong in this regard, allowing FRE Active to be estimated to within ±30% in the range 100–100,000 J s −1 m −2. These results provide further confidence in the ability of spaceborne missions to derive physically meaningful values of FRE that could be used to support biomass burning emissions inventories. Future comparisons between FRE derived via MODIS and those from higher spatial resolution BIRD or airborne imagery may allow the MODIS-derived FRE values to be ‘calibrated’ for any systematic underestimation. We therefore expect FRE to become an important tool for enhancing global studies of terrestrial vegetation fires with infrared remote sensing, particularly as the majority of large fires are now imaged four times per day via the MODIS instruments on the Terra and Aqua spacecraft.

Fire recognition potential of the bi-spectral Infrared Detection (BIRD) satellite

The potential of a new small Bi-spectral Infrared Detection (BIRD) satellite system for the detection and quantitative characterization of high-temperature events on the Earth surface is discussed. BIRD was successfully piggy-back launched by an Indian Polar Satellite Launch Vehicle (PSLV-C3) in a circular Sun-synchronous orbit on 22 October 2001. Images of wildfires in the area of Sydney, Australia, obtained in January 2002, illustrate the fire recognition potential of BIRD.

Airborne forest fire mapping with an adaptive infrared sensor

The international scientific community has called for more detailed data on vegetation fires to improve the understanding of their role in global atmospheric chemistry, and on fire itself as an ecosystem disturbance. The fire science community highlighted the value of information such as fire spatial distribution, timing, extent, energy release, burning efficiency and emissions. In order to obtain reliable information on these parameters, a combination of operational and experimental space-borne sensors with in situ and airborne sensor measurements is required. A small satellite demonstrator mission on Bi-spectral InfraRed Detection (BIRD) was prepared by the Institute of Space Sensor Technology and Planetary Exploration of the German Aerospace Center (DLR). It was successfully launched on 22 October 2001 into a 570 km sun-synchronous orbit. This paper presents new thermal mapping results obtained with the Advanced BIRD Airborne Simulator (ABAS) during a flight campaign over controlled forest fires in the open coal mining region of the Brandenburg country in Germany on 23 August 2001. These data have been successfully used to retrieve the effective area and effective temperature of forest fires by means of the application of the bi-spectral sub-pixel method.

Application of the Dozier retrieval to wildfire characterization: a sensitivity analysis

The demand for improved information on regional and global fire activity in the context of land use/land cover change, ecosystem disturbance, climate modeling, and natural hazards has increased efforts in recent years to improve earth-observing satellite sensors and associated methods for fire information retrieval. While sensor development has made considerable headway for fire monitoring with the recent launch of Terra in late 1999 and upcoming missions such as bispectral infrared detection (BIRD), FOCUS, and the National Polar-Orbiting Operational Environmental Satellite System (NPOESS), the retrieval of fire properties from satellite observations remains problematic. Current methods for determining properties of actively burning fires, for example, continue to be based on a simple two-component model developed by Dozier in 1981 [Remote Sens. Environ. 11 (1981) 221.]. Its limitations in terms of reliable operational fire property retrieval have been known for some time, although not examined in detail to date. With new measurements from recently deployed and evolving satellite systems, which offer key advantages for fire remote sensing, it is appropriate now to more comprehensively examine the heritage methodology for fire property retrieval. The results of a sensitivity analysis indicate that under realistic conditions the random errors in fire temperature and area retrieved using Dozier's method are ±100 K and ±50% at one standard deviation, respectively, for fires occupying a pixel fraction greater than 0.005 (this corresponds to a 5000-m 2 fire within a 1-km pixel). For smaller active fires, larger random and systematic errors are likely to occur.