A HYPERTEXT-BASED TRAINING APPLICATION ON THE ACCURACY 
AND PRECISION OF FIELD SPECTROSCOPY 
E.J. Milton, E.M. Rollin and A.More 
NERC Equipment Pool for Field Spectroscopy 
Department of Geography 
University of Southampton 
Southampton S09 5NH, U.K. 
ABSTRACT 
The paper describes two hypertext-based training applications developed by the UK Natural Environment 
Research Council Equipment Pool for Field Spectroscopy (NERC-EPFS). The first introduces NERC-EPFS and 
explains its role in loaning field spectroradiometers and associated equipment to UK research groups, and the 
training and research activities of the Pool. The second application is a systematic review of the accuracy of 
field spectroscopy and comprises five main sections: Primary standards, Instrument characteristics. Panel 
characteristics, Environmental factors and Measurement methodology . The written paper illustrates the type of 
material contained in the computer-based products by summarising three of the many experiments included. 
The first shows how changes in temperature have a strong influence upon the radiometric sensitivity of a 
Spectron SE590 spectroradiometer, particularly above 700nm.The second shows how in the field situation in 
temperate latitudes skylight moderates the non-lambertian properties of a Spectralon panel. The third 
experiment investigates the relative accuracy of measurements made with the sensor hand-held or held in a 
fixed support. No significant difference in nadir reflectance was measured from grass and asphalt surfaces 
using a Spectron SE590 spectroradiometer operated in the two modes. 
KEY WORDS: field spectroscopy, training, methodology, hypertext, errors 
1. INTRODUCTION 
In January 1988 the UK Natural Environment Research Council established an Equipment Pool for Field 
Spectroscopy (EPFS) located at the University of Southampton and this now comprises five inter-calibrated 
field spectroradiometers and associated instruments. The EPFS is staffed by a Pool Manager and a Research 
Assistant, and its main function is to provide field spectroradiometers to the UK research community, and to 
train prospective users in field spectroscopy. An important subsidiary role of the EPFS is to perform 
fundamental research on the methodology of field spectroscopy. 
Although much of the training undertaken by EPFS is 'hands-on' we have also identified a 
need for interactive computer-based training materials which can be distributed more widely, and have 
developed two hypertext applications using a program called Toolbook from Asymetrix Inc. 
2. HYPERTEXT APPLICATION 1 : THE NERC-EPFS TUTOR 
This application is intended as an introduction to the NERC Equipment Pool and its activities and comprises a 
series of modules linked through a contents page which is shown in figure 1. Introductory sections describe the 
function of EPFS and the various instruments available for loan, and nested modules within these sections 
allow the user to access more detailed information on the subject of field spectroscopy and a comprehensive 
bibliography. Other main sections cover the calibration of EPFS instruments and the system by which their 
calibration is traceable to the UK National Physical Laboratory. Considerable attention is also devoted to the 
different methods by which spectral reflectance may be measured in the field, and advice given on the practical 
aspects of field measurements. Finally, sections cover the procedure by which prospective users may apply for 
use of the instruments, and examples of completed studies are provided, together with a full set of information 
notes and technical data produced by EPFS staff. 
119