Remote sensing for resources development and environmental management: Remote sensing for resources development and environmental management

damen, m. c. j.

Bibliographic data

Multivolume work

Persistent identifier:: 856342815

Title:: Remote sensing for resources development and environmental management

Sub title:: proceedings of the 7th international Symposium, Enschede, 25 - 29 August 1986

Year of publication:: 1986

Place of publication:: Rotterdam; Boston

Publisher of the original:: A. A. Balkema

Identifier (digital):: 856342815

Language:: English

Additional Notes:: Volume 1-3 erschienen von 1986-1988

Editor:: Damen, M. C. J.

Document type:: Multivolume work

Volume

Persistent identifier:: 856662364

Title:: Remote sensing for resources development and environmental management

Sub title:: proceedings of the 7th international Symposium, Enschede, 25 - 29 August 1986

Scope:: VI, Seiten 959-1074

Year of publication:: 2016

Place of publication:: Rotterdam; Boston

Publisher of the original:: A. A. Balkema

Identifier (digital):: 856662364

Signature of the source:: ZS 312(26,7,3)

Language:: English

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Editor:: Damen, M. C. J.

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2016

Document type:: Volume

Collection:: Earth sciences

Chapter

Title:: Keynote addresses

Document type:: Multivolume work

Structure type:: Chapter

Chapter

Title:: Remote sensing applications: An outlook for the future. Herman Th. Verstappen

Document type:: Multivolume work

Structure type:: Chapter

While air photography evolved into remote sensing, the field of photo-interpretation widened to become image-interpretation. These developments are clearly mirrored in the subject matter presented at this, the seventh sympo sium of Commission VII. The number of contributions is almost tripled compared to 1962, a fact that is indicative of the growing inportance of remote sen sing for resource assessment. About one-third of these contributions (as compared to 4% in 1962) relate to technical aspects concerning, e.g., the hard and software used for the job. This trend is indicative of the spectacular technological growth in the field of space research and remote sensing in the past 24 years. When looking at the fields of applications, the marked increase of papers related to remote sensing of renewable resources deserves mention. This fact is readily explained by the introduction of multi- spectral remote sensing techniques which allow for reliable and even semi-automatic detection of crops, vegetation types, etc. This field has expanded sub stantially in recent years. The same techniques have also furthered remote sensing of surface water fea tures including water pollution. Contributions on the use of remote sensing for surveying non-renew able resources are distinctly less numerous. Al though this may in part be due to competition with other conferences, it is certainly also related to the fact that these resources normally cannot be directly detected on the basis of their spectral characteristics, although they may (or may not) be reflected in the spectral signatures of their veg etation or soil cover. Advances in this field are thus less distinct and await the inpulses provided by the stereoscopic satellite images that recently have become available and that are essential for earth science application of satellite imagery. While in 1962 emphasis was on detailed surveys many papers of 1986 deal with small-scale and medium-scale resource mapping projects. This is quite logical taking into account the fact that in 1962 aerial photographs were practically the only available tool, whereas the imagery of the first- generation high-resolution resource satellites, with a spatial resolution of about 80 meters, invites reconnaissance studies of large areas: More detailed studies require the additional use of aerial photo graphs in multi-phase approaches. It is of considerable interest in this context that earlier this year the first operational second- generation high-resolution satellite (SPOT) has become operational. The merits of these images, with a spatial resolution of 10 meters panchromatic and 20 meters colour and the potential of the stereo scopy that can be obtained, have been amply discuss ed during this symposium. One may thus say with justification that also this seventh symposium of Commission VII is taking place on the threshold of a new era of satellite remote sensing in much the same way as the first one coincided with an earlier major threshold. Monitoring and updating of maps using recurrent passes of high-resolution sun-synchronous satellites is the subject of several papers and relate to matters such as coastal development, river floods, etc. A number of authors have made use of images/data recorded by (NOAA) weather satellites which charac teristically have a low spatial resolution and a high temporal resolution. These images have lured meteorologists and oceanographers into the use of satellite imagery, thus considerably widening the circle of scientists engaged in remote sensing ap plications. In addition, these images serve a var iety of other purposes, such as the monitoring of vegetation changes, drought and desertification and they are even used in the context of locust control. Although not all these subjects may have received equal weight during this symposium, the applicabili ty of low resolution satellite imagery as a coun terpart of the second generation high-resolution, stereoscopic SPOT satellite data is fully realised by the participants. There has been made no mention of applications of extra-terrestrial remote sensing during this symposium, although this imagery is now available from the moon, a number of planets and planetoids and some of the moons of other planets. Some may consider this a lack of scientific imagin ation from the side of the participants while others may see it as reflecting a (too) low assess ment of extra-terrestrial (e.g., mineral) resour ces. MAIN TRENDS When considering the developments of the last few decades in a more general sense the following main trends emerge: A great diversification of sensors that has freed us from the limitations of the narrow visible spec trum and that now enable recording in all usable parts of the electro-magnetic spectrum from the micro waves, through the thermal infrared zone and the visible spectrum to the ultra-violet. A great diversification of recording altitudes which —leaving for a moment the extra-terrestrial recordings— now range from an altitude of 36,000 km for the geo-stationary (weather) satellites and an altitude of approximately 700-900 km for orbit ing (e.g., sun-synchronous) satellites to 250-300 km for the space shuttle and approximately 18,000- 200 meters for survey aircraft that include super altitude (stratospheric), conventional, low-flying reconnaissance and ultralight planes. Repeated recording at regular relatively short intervals became common practice. The possibilities for sequential interpretation of aerial photographs limited by a recording interval of usually years or decades is surpassed by the orbiting resource satellites giving a temporal resolution of less than one to several weeks (or, if cloud cover in- terfers: months) and by the geo-stationary satel lites that record near-continuously (interval of a few hours or days). There is, of course, a trade off here between spatial resolution and temporal resolution, which makes high and low resolution systems complementary. Rapid introduction of digitalization methods covering digital data recording, telemetering of data to groundstations and the subsequent data processing, and (semi) automatic interpretation techniques. Image enhancement ranks high in this respect and can be subdivided into digital methods for restoration of the images through geometric and radiometric corrections, for contrast improvement through histogram equalisation, density slicing, spatial frequency filtering, etc., and for (feature space) information extraction purposes by way of automatic classification, maximum likelihood ap proaches, intensity mapping and ratioing, principal component transformations, etc. A cascade of topographic and thematic information is being constantly poured down over our heads from satellites and other sources. Since the satellite remote sensing data are mostly digitized and give the precise geographical location of the recordings in X, Y (and Z) coordinates, storing the informa tion in a data base and its subsequent classifica tion and retrieval by way of a geographical (or land) information system (GIS/LIS) has become feas ible. In the context of planned development, there is a great need all over the world for rapid data acquisition and presentation and thus GIS/LIS hold a good promise for the future. The resource surveyors have become part of a lar ger community. As I have already mentioned, several scientific disciplines that never really were using aerial photographs, such as meteorology and oceano graphy, have deve remote sensing, p gery. The field o: resource developm grown substantial even relatively m surveyors share t logy with photoc topographic maps, measuring the she omers exploring < universe. The brs the effect of rap of science! In fac lite systems are planet, very subs quite different, s munications for s that governments amounts of money that the military craft are the re, undeniably exist resource surveyors in this respect: past hardly been resource surveying metrists and photc less greatly bene the military potei ably not even the pushing space res is developing ai fields such as su triggered. We are trial space era w to advanced techno utilization of hum between various ps our cultural heri nowadays are like attached to the s being thrust forwc ogy, we —living i applications that scientific and soc THE CHANGING FACE DEVELOPMENT The rise of aeros source surveying i different types an the same basic met] apply throughout, cated in Fig. 1. based on visible and relief element (usually) invisibli process of obser' verification that tations and conclu perfected data acq trained interprets obtaining optimum refined equipment quired to produce < The density can colours and relat cover, to surface soil or rock. Th stereoscopically, , data can be obtain terns. It is parti of terrain forms. V pretation both den; rather balanced pe satellite remote se strongly emphasise

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