48 
Ae BEST = sautomatio differential reotifijoation with.a 
simplified program 
  
In addition to the TOPAS program package which calculates 
control data for the differential rectification process 
from digital height models with arbitrary point arrange- 
ment, a simple program has been developed which processes 
the profile data obtained from on-line differential reèti- 
fication with digital control unit. Ths BEST program is 
written in FORTRAN IV and elaborated for minicomputer with 
64 kbyte main storage capacity. 
The BEST minicomputer program allows the utilization of 
the off-line differential rectification (cross-slope cor- 
rection, double model orthophoto production, repetitive 
rectification) in a simplified process, which is based 
on the TCPCCART/ORTHCPHOT system combination with digital 
control and cross slope correction, Input data are used 
which are recorded with the digital control unit in the 
output mode on data carriers in order to calculate control 
data for the off-line rectification process. The control 
data calculated with BEST have the same record format as 
the control records calculated with TOPAS (three-digit 
smoothed model height data: three-digit tangent data in- 
formation on the terrain cross slope). 
IRTHOPHOT D-300 offers the possibility to limit the length 
of each profile individually by a button so as to rectify 
only those parts of the model being of interest, for 
instance, for routes or map revisions. 
Therefore, the BEST program can also handle profiles of 
different lengths. If for one profile point only one or no 
neighbouring point at all is found by this, the calculation 
of the terrain cross slope is performed by simplified for- 
mulas and model smoothing is dispensed with. 
Differential rectifications performed with cross slope cor- 
rector result not only in a better image quality through the 
elimination of systematic errors but have also the essen- 
tial advantage that they can be carried out with at least 
the double slit width as compared to differential rectifi- 
cations without cross slope correction, Às is evident, 
this way Of rectification benefits the economy of ortho= 
photo production quite eonsiderably, Furthermore, control 
data for the same model area and the same model scale can 
be used as often as is desired, so that a special data bank 
with files is generated for the particular map sheets. 
The BEST program belongs io the standard equipment of the 
digital control unit. 
Deferences 
(1 Marekwardt, W.: "Application and accuracy of the TOPOMAT 
automatic restitution system", Presented Paper XIIIth ISP- 
Congress, Helsinki 1976, Commission II and Kompendium 
Photogrammetrie Vol. XIII (4979) p. 424 
Bürger, M.; Illhardt, E.: "Accuracy and reliability of 
the fully automatic TOPOMAT A photogrammetric restitution 
system", Surveying News 1980/1 pp. 21-23 
——J 
Ur 
PO