other areas. Soil. moisture data can be estimated from 
meterological stations in the region of interest. 
The radar cloud model failed to give reasonable results in water 
stress conditions. More testing is required before including this 
type of model in monitoring and yield prediction. The Xu ef al. 
(1996) model was basically tested on sugar beet in the East 
Anglia region only and should also be tested in other areas. 
The ERS-1 and ERS-2 SAR data have been shown to be 
sensitive to leaf area during the whole growing season of sugar 
beet. Thus, ERS SAR data are expected to be a viable 
alternative to existing optical data in an operational sugar beet 
yield forecasting system. Further validation of the model with 
RADARSAT C-band HH polarization, which has high 
temporal resolution, a range of 20? to 50? incidence angle and 
same day/night revisit capacity data, has still to be made. 
10. REFERENCES 
ATTEMA, E.P.W. and ULABY, F.T., 1978, Vegetation modelled 
as a water cloud, Radio Science, 13, 2, pp357-364. 
BIRD, P.J., 1997, Final report for ERS-2 SAR Calibration 
activities. DERA/CIS/CIS2/CR/97069/1.0, 02 June 
1997. 
BOUMAN, B.A.M., 1992, Linking physical remote sensing 
models with crop growth simulation models, applied 
for sugar beet. International Journal of Remote 
Sensing, 13, 2565-2581. 
DOCKTER, K. and KUHBAUCH, W., 1990, Capability of 
multifrequency and multi-polarization SAR-systems 
in remote sensing of crop species and crop yield. 
Proceedings of the 10th Annual IGARSS Symposium, 
University of Maryland, Washington DC, USA, May 
20-24, III, 2197-2200. 
KoHL, H-G., KiNG, C. and DE GROOF, H., 1994, Agricultural 
statistics: Comparison of ERS-1 and SPOT for the 
crop acreage estimation of the MARS project. 
Proceedings of the Second ERS-1 Symposium: Space 
at the Service of our Environment, 11-14 October 
1993, Hamburg, Germany, 1, 87-92, ESA SP-361. 
LAUR, H., BALLY, P., MEADOWS, P., SANCHEZ, J., SCHAETTLER, 
B. and LoPiNTO, E., 1997, Derivation of the 
Backscattering coefficient 6° in ESA ERS SAR PRI 
products. ESA document:ES-TN-RS-PM-HLO09, 2, 3, 
41 pp. 
LEEUWEN, H.J.C. VAN and CLEVERS J.G.P.W., 1994, Synergy 
between optical and microwave remote sensing for 
crop growth monitoring, Proc. Sixth Int. Symp. 
IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India,2002 
Physical Measurements and Signatures in Remote 
Sensing, 17-21 Jan. 1994, Val d’Isere, France, pp 
1175-1182. 
MEADOWS, P.J. and WRIGHT, P.A., 1994, ERS-1 SAR analogue 
to digital convertor saturation. Proceedings of the 
SAR Calibration Workshop, CEOS 
Calibration/Validation Working Group, Ann Arbor, 
Michigan, USA, 28-30 September 1994, 24-37. 
MONSI, M. and SAEKI, T., 1953, Uber den Lichtfaktor in den 
Pflanzengesellschaften undseine Bedeutung fur die 
Stoffproduktion. Japanese Journal of Botany, 14, 22- 
52. ; 
SCOTT, R.K. and JAGGARD, K.W., 1992, Crop growth and 
weather: Can yield forecast be reliable. Proceedings 
of the 55th winter congress 12-13 February 1992 
(Brussels: International Institute for Sugar Beet 
Research), 169-187. 
STEVEN, M.D., BISCOE, P.V., JAGGARD, K.W. and PARUNTU, J., 
1986, Foliage cover and radiation interception. Field 
Crops Research, 13, 75-87. 
WERKER, A.R. and JAGGARD, K.W., 1997, Modelling 
asymmetrical growth curves that rise and then fall: 
Applications to foliage dynamics of sugar beet (Beta 
vulgaris L.), Annuals of Botany, 719, 657-665. 
WOODING, M.G., GRIFFITHS, G.H., EVANS, R., BIRD, P, 
. KENWARD, D. and KEvTE, G.E., 1993, Temporal 
monitoring of soil moisture using ERS-1 SAR data. 
Proceedings of the First ERS-1 Symposium: space at 
the service of our environment, 4-6 November 1992, 
Cannes, France, 641-648. ESA SP-359. 
WOODING, M.G., ZMUDA, A.D., BROWN, R.E. and PEKHOLTZ, 
F., 1997, A Crop Information System Incorporating 
ERS SAR Data: Applications in the UK and 
Paraguay. Proceedings of the 3rd ERS Symposium: 
space at the service of our environment, 17-21 March 
1997, Florence, Italy, ISBN 92 9092 656 2, ESA SP- 
414. 
XU, H., STEVEN, M.D. and JAGGARD, K.W., 1996, Monitoring 
leaf area of sugar beet Using ERS-1 SAR Data. 
International Journal of Remote Sensing, 17, 3401- 
3410. 
Xu, H., STEVEN, M.D. and Vyas, S.P., 1995, Logistics of data 
combination in the crop profile model. Technical 
Note submitted to Logica, UK, SBP-UN-TN-009, 1, 
12 May 1995, 22pp. 
    
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