Some considerations: 
|. It is advisable to express quality requirements in terms of physical figures rather than in descrip- 
tive wording - as much as is reasonable feasible. 
In this respect, it is regretted that, until today, no useful method is available yet which could measure 
the degree of contrast attenuation of imagery by the aerosol (e.g. haze), which means that the amount 
of permissable haze must be described in wording instead of by means of values (para. 3.3.3.). 
Some descriptive specifications, howver, have been replaced by figures (e.g. in 2.4 camera windows). 
2. Sample checks on the metric quality are suggested, to reduce the chance for the user to get into 
troube at the aerial triangulation stage - i.e., long after the photography has been accepted (paragraphs 
45.1.3., 4.5.3. and 4.6.). 
3. Specifications are needed not only in cases of commercial contracting but in all cases where any 
Aerial Photography Organization, Department or Service produces photography for any user. Thus, we have 
modified the wordings: "contractor", "client" and "contract" into: "producer", "client or user" and 
"project". 
4. To preclude micunderstanding and disagreenent in terminology, it will be useful to commence the 
Specifications by giving Definitions. 
INTERMEDIATE PRODUCT 
The underlying draft "Specifications..." is intended to be one link in the continuous chain of up- 
datings which will be needed to increase and to maintain the usefulness of the document and to get the 
Specifications adopted by the ISP. 
The present Specs are designed for the purpose of line mapping and mosaicing only. 
With the increased use of orthophoto, of colour, false colour and multi-spectral imagery, it will be 
necessary - although more difficult - to cover these aspects as well - by further Specifications. 
Work is under way to extend them for the purpose of orthophoto mapping and is expected to be ready 
before the 1984 ISP Congress. 
Comments for further updating are invited. To make this workable in practice, it is suggested that 
input of comments and suggestions be given via a few entry ports, for instance: 
U.K.: RICS 
Royal Institute of Chartered Surveyors 
12, Great George Street 
Parliament Square 
LONDON SWIP 3AD 
U.K. 
Netherlands: ITC 
International Institute for Aerial Survey and Earth Sciences 
P.0. Box 6 
7500 AA ENSCHEDE 
The Netherlands 
USA and Canada: „....,....0...00.00000002020200% 
195