Remote Sensing: Background research (1978 – 1989)


Remote Sensing: background research (1978 – 1989)

Unfortunately, not much has been recorded about the period 1978-1989. Still, it was an important time, as the work that began with NIWARS continued in a systematic manner. For a number of years, radar measurements were taken on agricultural crops, soils, water waves, sea surface (first years on the Noordwijk measuring platform, the old REM island, and later also at other places and from ships), etc. These activities led to a deepening of the insight into the physics behind the observations. In the meantime, modelling and simulation have made much more progress. It led to the insight that more accurate measurements had to be taken. Calibration was necessary and the equipment had to become stable.

The flying radar recorded the observations on wet film. That medium was replaced by magnetic tape recording in the late 1970s. That soon proved to be not enough. Work started on a digital SLAR built with a ship’s radar unit. Advancing digitisation helped to improve quality, for example by using image processing equipment (Comtal), digitisation equipment and the rise of the PC in 1980. 

The Comtal image processing system
The Comtal image processing system

Great results were achieved with the visual material. Crop classification, for example, but also the measurement of wave direction spectra at sea. The insight grew that the equipment had to be improved and that this aim was achievable. A coherent radar that can do phase measurements and accurate amplitude measurements had to be developed. In 1986 this led to the start of a coherent radar study, which resulted in the later development of a Dutch SLAR, the PHARS and PHARUS systems. In August 1986, SLAR images were made of the Flevopolder (3 by 5 km). So a lot of time has passed from these first ideas to the first PHARS image in the 90s.



Prof. Peter Hoogeboom provided additional information on the period 1978-1989.  

  1. J.Ph. Poley: “Note on the resolution of radar systems”; Tijdschrift Nederlands Radiogenootschap, vol.22, 1957, pp. 187 – 194. 
  2. H.M. Oudshoorn: “The use of radar in hydrodynamic surveying”; Procs Seventh Conference on Coastal Engineering, edited by J.W. Johnson (The Hague: Council on Wave Research, The Engineering Foundation), 1960, pp. 59 – 76.
  3. G.P. de Loor, A.A. Jurriëns, W.J.M. Levelt and J.P. van de Geer: “Line-scan imagery interpretation”; Photogrammetric Engineering, vol.34, 1968, pp. 502 – 510.
  4. G.P. de Loor, A.A. Jurriëns and H. Gravesteijn: “The radar backscatter from selected agricultural crops”; IEEE Trans. Geoscience Electronics, vol. GE-12, 1974, pp. 70 – 77.
  5. G.P. de Loor, “Possibilities and uses of radar and thermal infrared systems”, Photogrammetria, vol.24, 1969, 43 – 48.
  6. RWS werkgroep, nota: “Radar en infra-rood luchtopnamen”, door Afd. Havenmonden bij brief nr. 128 dd. 10 jan. 1969 aangeboden aan de HID RWS in de Directie Benedenrivieren.
  7. ITC rapport: “Voorstel tot applikatie onderzoek van moderne lucht-opname technieken”, aangeboden aan de Minister van O en W, 10 jan. 1969.
  8. Interdepartementale Werkgroep Applikatie Onderzoek Moderne Luchtopname Technieken: “Concrete voorstellen voor het applicatie onderzoek van moderne luchtopname technieken”; Nota op 5 dec. 1969 uitgebracht aan de Minister van O en W, mede ten behoeve van zijn ambtgenoten.
  9. Verslag van het Symposium “Luchtwaarneming met niet-conventionele systemen”; De Ingenieur, vol.33, 1970, Afd. TWO nr.6 pp. o71 – o100 (6 artikelen, verslagen van het werk verricht van 1962 tot 1969).
  10. W. Alpers and I. Hennings: “A theory of the imaging mechanism of underwater bottom topography by real and synthetic aperture radar”; J. Geophys. Res., vol.89, 1984, pp. 10529 – 10546.
  11. Maritiem Geodetisch Bureau C. Don: “Proefopnamen met side looking airborne radar”; rapport samengesteld in opdracht van RWS, Directie Benedenrivieren, Afd. Havenmonden, Sectie Noordzee, 1970. Een herdruk verscheen in de RS Nieuwsbrief nr. 89, dec. 1999.
  12. “Verslag van een oriëntatiereis door de USA door een W.A.C.-delegatie in de periode van mei-juni 1971 in opdracht van de Stuurgroep van NIWARS”; ingediend door de voorzitter van de Stuurgroep op 15 nov. 1971.
  13.  N.J.J. Bunnik: “The multispectral reflectance of shortwave radiation by agricultural crops in relation with their morphological and optical properties”; Thesis Wageningen, 18 Jan 1978, also in: Comm. Agricultural university Wageningen, 78-1 (1978).
  14. G.P. de Loor, P. Hoogeboom and E.P.W. Attema: “The Dutch ROVE Program”; Trans. IEEE Geosci. and RS, vol.GE-20, 1982, pp. 3 – 11.
  15. Eindrapport NIWARS, rapport uitgebracht door de Stuurgroep van het beleidsruimte project NIWARS, 1 juni 1977.
  16. R.H.J. Morra: “Het begin van de remote sensing in Nederland”, 1958 – 1986”; publicatie van de Kring voor RS, maart 1990.
  17. L. Krul en G.P. de Loor: “Experiments with microwaves”; Int. J. Remote Sensing, 1992, vol. 13, nos. 6 and 7, 1201-1216.