1、Designation: F 2327 03Standard Guide forSelection of Airborne Remote Sensing Systems forDetection and Monitoring of Oil on Water1This standard is issued under the fixed designation F 2327; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide provides information and criteria for selec-tion of remote sensing systems for the detec
3、tion and monitor-ing of oil on water.1.2 This guide applies to the remote sensing of oil-on-waterinvolving a variety of sensing devices used alone or incombination. The sensors may be mounted in helicopters,fixed-wing aircraft or lighter-than-air platforms. Excluded aresituations where the aircraft
4、is used solely as a telemetry orvisual observation platform and exo-atmosphere or satellitesystems.1.3 The context of sensor use is addressed to the extent ithas a bearing on their selection and utility for certain missionsor objectives.1.4 This guide is generally applicable for all types of crudeoi
5、ls and most petroleum products, under a variety of marine orfresh water situations.1.5 Many sensors exhibit limitations with respect to dis-criminating the target substances under certain states of weath-ering, lighting, wind and sea, or in certain settings.1.6 This guide gives information for evalu
6、ating the capabil-ity of a remote surveillance technology to locate, determine theareal extent, as well as measure or approximate certain othercharacteristics of oil spilled upon water.1.7 Remote sensing of oil-on-water involves a number ofsafety issues associated with the modification of aircraft a
7、ndtheir operation, particularly at low altitudes. Also, in someinstances, hazardous materials or conditions (for example,certain gases, high voltages, etc.) can be involved. Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility
8、of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory require-ments prior to use.2. Significance and Use2.1 The contributions that an effective remote sensing sys-tem can make are:2.1.1 Provide a strategic picture of the overall
9、 spill,2.1.2 Assist in detection of slicks when they are not observ-able by persons operating at, or near, the waters surface or atnight,2.1.3 Provide location of slicks containing the most oil,2.1.4 Provide input for the operational deployment of equip-ment,2.1.5 Extend the hours of clean-up operat
10、ions to includedarkness and poor visibility,2.1.6 Identify oceanographic and geographic features to-ward which the oil may migrate,2.1.7 Locate unreported oil-on-water,2.1.8 Collect evidence linking oil-on-water to its source,2.1.9 Help reduce the time and effort for long range plan-ning,2.1.10 A lo
11、g, or time history, of the spill can be compiledfrom successive data runs, and2.1.11 A source of initial input for predictive models and for“truthing” or updating them over time.3. Remote Sensing Equipment Capabilities andLimitations3.1 The capability of remote sensing equipment is, in largemeasure,
12、 determined by the physical and chemical propertiesof the atmosphere, the water and the target oil. There may bevariations in the degree of sophistication, sensitivity andspacial resolution of sensors using the same portion of theelectromagnetic spectrum and detector technology. Sensorswithin a give
13、n class tend to have the same general capabilitiesand typically suffer from the same limitations.3.2 Combinations of sensors offer broader spectral coveragewhich, in turn, permit better probability of detection, betterdiscrimination, and effective operation over a broader range ofweather and lightin
14、g conditions. Certain combinations, orsensor suites, are well documented, and their use is particularlysuited to oil spill response missions.1This guide is under the jurisdiction of ASTM Committee F20 on HazardousSubstances and Oil Spill Response and is the direct responsibility of SubcommitteeF20.1
15、6 on Surveillance and Tracking.Current edition approved Nov. 1, 2003. Published December 2003.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.3 The performance of virtually all sensors can be en-hanced by a variety of real-, near r
16、eal-time or post processingtechniques applied to the acquired data or imagery. Further-more, image or data fusion can greatly enhance the utility ofthe remote sensing output or product. Similarly, there exists avariety of technological considerations and organizationalramifications that relate to th
17、e delivery of the remote sensinginformation to the user.3.4 Certain parameters need to be identified and quantifiedto provide an oil spill response decision-maker with all of theinformation needed to best respond to a spill. These are:3.4.1 Locationof the approximate center and edges of thespill,3.4
18、.2 Geometrysource or origin, total area, orientationand lengths of major and minor axes, fragmentation, anddistribution,3.4.3 Physical conditionsoil appearance, entrained debris,3.4.4 Environmental conditionswave height and direc-tion; water temperature; position of oceanic fronts, conver-gence and
19、divergence zones,3.4.5 Proximity of threatened resources, and3.4.6 Location of response equipment.3.5 Remote sensing can contribute to all of the above dataneeds. Depending on the spill situation and the employment ofremote sensing, some of this information may already beavailable, or can be determi
20、ned more cost effectively by othermeans. For example, in a response mode, or tactical employ-ment of remote sensing, it is likely that the source, generallocation and type of oil have been reported well in advance ofthe launch of the remote sensing platform. In a regulatory orpatrol context, this in
21、formation may not be available. The spillsituation influences the priorities among the elements ofinformation and, thereby, influences the selection priorities forsensors.3.6 A responder may require the data on an oil spill, 24hours per day, independent of the prevailing weather.3.7 Information from
22、 remote sensing is required in a timelymanner. Strategic or enforcement information, such as theoverall extent and location of a spill, should be availablepreferably within two to four hours from information gatheringto presentation.3.8 Tactical information, such as steering information forresponse
23、vessels, should be available in as little as five minutesfrom detection to communication. The acceptable data deliverytime is a function of the dynamics of the slick, proximity tocritical areas, and the availability of clean-up resources.3.9 No sensor is currently available to give information onoil
24、 thickness. Relative thickness information of the form, thickor thin, can be derived from an infrared camera.3.10 Table 1 lists sensors based upon their mode of opera-tion. Summary information on their advantages and disadvan-tages is presented.3.11 Table 2 presents a summary of key attributes which
25、generally influence the selection of remote sensing instrumen-tation.3.12 Table 3 addresses the mission specific aspects of sensorselection.4. Summary4.1 The information presented in this guide should beconsidered a starting point for sensor selection. In addition tothe context of use and the attrib
26、utes of the various types ofsensors, the system planner will have to give due considerationto the capabilities of the aircraft and the information needs ofthe users before finalizing the system design. Both sensortechnology, and image and data analysis capabilities areevolving rapidly. Most equipmen
27、t is not commercially-available and requires assembly and in some cases requiresdevelopment. Up to two years lead time may be required forsome equipment.F2327032TABLE 1 Sensor CharacteristicsSensor/ Band Principal of Operation Positive Features LimitationsVisual Operate in, and near, the (human) vis
28、ible spec-trum (400 to 750 nm). Using photographic films,scanners with one or more narrow band detectorsor charge coupled devices (CCD) to capture animage.Equipment is widely available, generallyinexpensive, light and easily accommodatedon most any aerial platform. Imagery is in every-day use and th
29、e layman can easily relate to itscontent. This characteristic makes the imageryan excellent base for recording and presentingother data.Oil is generally perceptible over the entire visiblespectrum, but not uniquely so. As such, instancesof not being able to discriminate the oil from itsbackground, o
30、r differentiate it from othersubstances or phenomena in or on the waterssurface, lead to frequent non-detects and falsepositives.Low level light TV may extend the operationalwindow, but visual technologies are limited byavailable light.Infrared While the infrared (IR) spectrum ranges from 750nm to 1
31、 mm, the bulk of the available remotesensing systems operate in the thermal or mid-IR,3 m (3000 nm) to 30 m (30 000 nm). Withinthis range there are two predominant sub-groupsoperating at 3 to 5 m and 8 to 12 or 14 m.The latter range offers the most useful data foroil spills.Fresh oil shows a somewha
32、t contrast to openwater in the thermal infrared. This characteristicis not unique to hydrocarbons. Slicks thickerthan about 20 to 70 mAcan be seen.Newer IR cameras have excellent thermaldiscrimination, fairly good resolution, are light-weight, have modest power demands, andtypically have both digita
33、l and video outputs.Small patches, thin, or significantly weathered oilmay not be detectible. Other heterogeneities suchas high seaweed or debris content, oil in or on ice,oil on beaches, etc. may render the oilundetectable in the IR.There is no relationship between slick thicknessand the intensity
34、of the IR image.In the daytime thick oil is hotter than water and oilof intermediate thickness is cooler. (The cross overwith water occurs when the oil is about 20 to150 m thick.B) At night this relationship reverses(unless the spill is fresh and the oil is hotter thanthe water when it arrives at th
35、e surface).This results in two periods per day with poordiscrimination.Ultraviolet Oil is highly reflective in the ultraviolet (UV200to 400 nm).Very thin (10 nm) layers of oil can be detectedin the UV.CThus, even sheen, a common regu-latory definition of oil pollution, can be delin-eated.UV cameras
36、have fairly good resolution,are light-weight and have minimal powerdemands.High UV reflectance is not unique to oil. Sun glint,biogenic and other materials and phenomena canyield strong returns in the UV.This technology is limited to available lightsituations, and is best used in combinationwith oth
37、er sensors, typically IR.Radar Oil has a damping effect on high frequency, lowamplitude (1 to 10 cm) capillary waves. Thesewaves, yielding a “rougher” surface, returnconsiderably more radar energy to the receiverthan calm water. As such, under the properconditions, oil can appear as a low return, da
38、rkarea in a larger, bright field of un-oiled waves.Specially tuned Side Looking Airborne Radar(SLAR) and Synthetic Aperture Radar (SAR)are the only two types suited to the oil detectiontask. Search and weather radars can not be usedinthis role.Radar has some unique advantages over otheroil spill sen
39、sors: it can operate day or night; itcan operate in times of reduced visibility; it canoperate at higher, safer and more fuel-efficientaltitudes, and; it is outward, rather than down-wardlooking, making it the only area searchtechno-logy available for oil spills. Typicalranges are 10 to 50 km.Oil is
40、 not the only source of calms. Other, naturallyoccurring substances and phenomena can giverise to smooth water.DIf the prevailing wind is lessthan about 1.5 m/s, there will not be enough“roughness” in un-oiled water to create thenecessary roughness contrast. Likewise, aboveabout 6 m/s the calming ef
41、fect of, at least thin,oil begins to wash out.EThe potential for falsepositives is high.Radar equipment is expensive and it requires fairlyextensive modifications to an aircraft, thus addingto both the acquisition and the operational costs.MicrowaveRadiometerOil is a stronger emitter of microwave ra
42、diationthan water (emissivity factor of 0.8 versus 0.4,respectively).FTherefore it shows up as a brightarea against a darker background.The passive microwave radiometer has beendemonstrated to detect oil on water even underlow visibility conditions.The technology is subject to the same limitationsas
43、 radar.This is an evolving technique requiring additionaldevelopment and demonstration before acommercial unit is marketable.Current units are installed in dedicated aircraft andthis trend is likely to continue in the near term.Fluoro-sensorsOil targeted or illuminated with UV lightwill adsorb this
44、energy and re-emit, or fluoresce,in the visible band. Other materials fluoresce aswell, but there is enough spectral uniquenessto oil to render it readily discernable. In fact it ispossible that various generic types of oil andpetroleum products can be differentiated.The coherent light from a laser
45、permits thedelivery of more energy from greater distancesmaking an airborne fluorosensors feasible.The laser fluorosensor permits the positiveidentification of oil and even permits somediscrimination between types of oil.It appears to be the only sensor available todaythat permits the detection of o
46、il against complexbackgrounds as is the case with oil on beachesand in, or with, the ice.Todays laser fluorosensors are fairly bulky andrequire significant modifications to relatively large,dedicated aircraft.AFingas, M. F. and Brown, C. E., “Review of Oil Spill Remote Sensors,” Proceedings of the S
47、eventh International Conference on Remote Sensing for Marine and CoastalEnvironments, Veridien, Ann Arbor, Michigan, 2002, p. 9.Bibid.CFingas, M. F. and Brown, C. E., “Review of Oil Spill Remote Sensing,” Proceedings of SPILLCON 2000, Australian Marine Safety Authority, Sydney, Australia,.au/spillco
48、n/, 2000.DFrysinger, G. S., Asher, W. E., Korenowski, G. M., Barger, W. R., Klusty, M. A., Frew, N. M., and Nelson, R. K., “Study of Ocean Slicks by Nonlinear Laser Processesin Second Harmonic Generation,” Journal of Geophysical Research, 1992.EWisman, V., Alpers, W., Theis, R., and Hhnerfuss, H., “
49、The Damping of Short Gravity-Capillary Waves by Monomolecular Sea Slicks Measured by AirborneMulti-frequency Radars,” Journal of Geophysical Research, 1993.FUlbay, F. T., Moore, R. K., and Fung, A. K., Microwave Remote Sensing: Active and Passive, ArchtHous, Inc., 1989.F2327033ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringeme
