PRINCIPAL PROBLEMS IN USING REMOTE 
SENSING DATA AND RECOMMENDATIONS 
FOR“ THEIR SOLUTTON 
Sens ors 
Many improvements in sensor technology could be made which would 
make remote sensing data more useful to natural resource users. Such 
things as improved resolution, faster availability of LANDSAT imagery 
and CCT's, and a declassification of military sensors and processing 
equipment. 
Standardization of aerial photography 
The exposing and printing of aerial photography has largely been an 
empirical exercise of estimating exposure (with or without an exposure 
meter) and processing the film to an acceptable density (gamma) level. 
While there have been noticeable differences among different batches of 
the same film emulsions, the film manufactures do attempt to keep the 
film and dye sensitivities as comparable as possible. This effort is 
all for naught if exposure and processing are not done carefully. In 
other words, more quantitative methods are needed if we can hope for 
comparable results from one photo mission to the next. Furthermore, if 
we expect to relate spectral differences on film to reflectance energy 
levels for image enhancement or use with microdensitometer scanning for 
automatic interpretation, consistent procedures should be followed. 
LaPado and Ekstrand (1974) report on one method to standardize CIR 
film response by establishing a sensitmetric aim point by which all new 
film batches are compared. By using color compensation filters and 
changes in basic exposure, the new film is exposed to produce imagery 
with the response characteristics of the aim curve. Other users, such 
as the Forest Service Remote Sensing Work Unit and the L. B. Johnson 
Space Center (NASA) are using similar methods (sensitometer gray scale 
wedges) to determine whether film has been properly processed. 
An improvement could be made also in aerial cameras by including on 
the data bank a gray scale formed by sending light through fiber optics 
which touch the back side of the camera lens. Thus, a normal range of 
gray scales would indicate proper exposure and other than normal -- 
either over or underexposure. 
Airborne haze meter 
Aerial imagery is often degraded because of atmospheric gases, smoke 
and water vapor. The amount of such interference is like static in a 
radio receiver; it degrades the quality of the signal.  LANDSAT invest- 
igators and aerial survey companies have been aware of the differences 
in quality of their images due to atmospheric interference. 
Only rough estimates of the amount of interference have been made 
from aircraft. When considerable haziness exists, the aerial photographer 
uses a yellow filter on panchromatic film or a deeper haze filter on color 
film to reduce Rayleigh scattering (where particles are smaller than wave- 
length) and he also increases his exposure to compensate for the filter