The data collection is controlled by a desk top calculator (Hewlett 
Packard 9810) with a cassette memory. This has two obvious advantages: 
1) all spectrometer data are digitized and area codes, time etc. are 
automatically stored and 2) mistakes during the measurement procedure 
can be avoided by means of validity checks. 
  
An X/Y chart recorder can be connected to the instrument and a camera can 
be mounted aligned to the telescope. The equipment set up in a "cherry- 
picker" ready for measurements at a test site is shown in fig l. 
It is not possible to make simultaneous measurements of the incident and 
the reflected light. Consequently, the calculation of bidirectional 
Fig. 1. The tele-spectro-radiometer fit for measurement. 
  
  
  
  
  
lonis