Current space assets provide very crude spatial and temporal data on the spectral bands which are of interest for the detection of forest fires. In fact, it can be said that no serious attempt has been made till now to investigate the potential benefits of space observation for the suppression of fires in the Mediterranean forest areas, among others.
Within the FUEGO Programme, a group of companies and institutions are taking the initiative to create in the near future a satellite system capable of satisfying most of the information needs identified in the forest fire detection and fighting issues. A combination of actual fire data, environmental conditions, site characteristics and available fighting resources are needed to provide personnel in the field with final and real time recommendation on how to use the resources under their control.
The FUEGO System is intended to be a constellation of new generation small, low cost satellites which integrate two band infrared instruments with a powerful processor to obtain on board the detection of fires with high resolution and the identification of fire line position and intensity in the monitoring mode. The synoptic data are then directly downlinked to the field, where it can be received by a hand held device on the ground or on board of an aircraft.
A basic support of this programme is the direct and continuous relation with potential users as it is highlighted by the two user conferences which are included in the FUEGO schedule. These conferences are intended to provide an agreement on the requirements of the system and on the interest of the results obtained.
Various aspects of fire can be sensed, including the energy released by active fires, smoke, char and scars. The mid-infrared (MIR) radiant flux from active fires is by far the strongest, and MIR sensing has been considered the most likely approach for global fire monitoring. The erratic characteristics of flames and fuels are related to complex chemical and physical processes, making experimental control difficult, but a characterisation of the fire IR signature is possible and will be obtained as a result of bibliographic analysis, laboratory experiments and open air experiments. This forest fire analysis is essential in obtaining the FUEGO System initial requirements, which are:
to detect fires in the high risk zones with an envisaged average detection time of half an hour, and convey the information to the user. A reduce average detection time should be available with a modular increase in the number of satellites;
to monitor fires with resolution on ground 30-50 m, and enough radiometric accuracy to allow fire fighting activities, while providing data every two hours;
to generate statistical data for fire management.
Additionally, it is convenient to investigate ways to provide a rough indication of local wind direction at the time of detection.
Several instruments are currently used on board of available platforms to sense forest fires. They are currently providing global scale fire data which has made satellite remote sensing suitable to final users. However these non-dedicated satellite systems are still unsatisfactory due to some inherent constraints. Since current systems do not produce imagery or data with the special characteristics required by the fire community, the FUEGO Programme intends to establish the basis of a space system devoted to forest fire fighting and will proceed by analysing the removal of each constraint and limitation identified in current systems, such as:
Revisit time limitations
Detector saturation problems
Spatial resolution limitations
Obscuration and uncertainty problems
Regarding the sensor required in the FUEGO mission, infrared sensors have been selected since they have been shown to be the most appropriate in fire studies. Furthermore, to improve resolution (sub-pixel detection) and filter false alarms multiple band sensors will be used.
In order to achieve the global mission, data provided by the detector must be properly processed on board by extracting and forwarding useful data from the raw source. The following scheme represents a block diagram of the data flow. The specific activity of manipulating imagery is carried out in the payload processor, although the Command and Data Handling Subsystem is in charge of controlling global on-board activity.
The system provides three autonomous modes of operation:
Detection of fires within the designated risk areas: The complete system will be able to detect forest fires and convey the facts in a matter of minutes. To do that it is not necessary to downlink an image but the location and intensity of the fire. Usually, at the start of the fire season, fire fighting command centres are located in the field to control operations. These centres are provided with tools such as personal computers to help in the management of fires, and communication equipment to allow continuous contact with forefront forces and with logistic centres and central authorities. The FUEGO system is intended to provide fire onset occurrence alarm, position, and severity to this command post in the shortest period possible, processing the sensed field of view to detect the would-be fires and checking this detection for consistency and false alarms.
Monitoring of designated fires and hot spot detection within the fire perimeter: The system is able to monitor a previously detected forest fire, regardless of the method used. For this purpose, it is necessary to obtain an image in which the interesting areas are shown. The command centre in the field selects the area to be inspected. The sequence of observation is prepared on board by allocating priorities to users and regions. Among other, the satellites then provide data on the position of the fire line and fire temperature, to the field fire chiefs, in the fastest way possible. The processor tasks include maintaining the operation sequence, pointing the mirror to the target, reading data from the detector, filtering data using calibration parameters, processing information, and ordering image downlink.
Risk management functions: Tasks include monitoring the status, the performance of calibration measures, control mode switch, follow external orders and fundamentally to plan the surveillance pattern as a function of the risk areas, determined as a result of NDVI or TS, and the cloud cover.
In order to satisfy user requirements and to overcome the limitations mentioned above, the FUEGO Programme Payload Study is structured in two closely interconnected phases:
Phase 1: System requirement definition and studies
From the user need studies, an operational concept will be developed. Inputs to carry out specific studies on system elements will be provided and a set of technical requirements which define the system will be gathered. An initial user conference will be organised to present the system and consolidate user requirements.
Phase 2: Trades-off, detailed payload definition and system planning
Further iterations will provide a preliminary design of payload elements, ancillary subsystems and interfaces. System specifications will be gathered. The economical analysis of the system will be performed. A final user conference will allow the assessment of the global work and distribute results.
User directions are essential to carry out the FUEGO Programme Payload Study in establishing solid requirements and ensuring the economical viability of the system. Thus future users are an active partner in the programme through the User Committee and the User Group. The first one is a small Committee of User Representatives that actively monitors the progress in the FUEGO System Definition, while the User Group is an open group of future potential users who are continuously provided with relevant information about the FUEGO Programme and who eventually join in the conferences.
At present the programme is starting a feasibility and definition phase, supported by the EC, DGXII, under the E&C programme. INSA is the coordinator and the contractors are Officine Galileo, INTA and SEMA Group. The research institutes INIA and CIF are associated contractors. The User Committee is presently being formed, and the first User Conference will be held in May 1997 in Spain.
It is expected that a service demonstration prototype will be flown in 1999 with the Small Mission Opportunity initiative of the ESA, with full constellation in place by 2001.
From:INSA, S.A. Attn. Mr. Cristóbal Martín-Rico, Director de Ingenieria Address: INSA, S.A. C/ Orense 4 E – 28020 Madrid