chosen. Simulated data are available from 5 strips with 10-11
models each, 8 photogrammetric points per model, camera prin-
cipal distance: 150.00mm, photo scale: 1:30000, in order to
ascertain the relationship between signal-to-noise ratio and
compensation of systematic errors, pseudo-random observational
errors with mean square error of 5, 10 and 154m respectively
according to normal distribution have been incorporated to
coordinates of photo points. Two sets of practical data are
selected. One set of data came from block data of Enping Test
Field of Guangdong Province, in the block there are 8 strips
with 16 models each, the Whole block consists of 128 models
with 8 planimetric and height point situated along perimeter
of the block, 88 planimetric and height check points, 37
height control points stabilized by 3 chains, layout of other
19 ones act as discret points is taken. All control points
and check points are with surface marks, camera principal
distance: 152.06mm, photo scale: 1:35000. The other set of
data are given from HORDORF test field of the Federal Re-
public of Germany, the data used are available from 5 strips
with 27-28 models each, the whole block consists of 136
models with 6 planimetric points situated at the upper and
lower strips respectively, 45 planimetric check points,
18 height control points stabilized by 3 chains, i=14b,
111 height check points, camera principal distance: 152.75mm,
photo scale 1:6000.
2. Experimental approach
While experiments are performed by using simulated data,
not only had pseudo-random errors been added, but systematic
errors incorporated artificialy, e.g. the change of theoretical
fiducial value to produce distortion of planimetric system and
that of correction parameter of atmospheric refraction to
produce deformation of height system and to render these two
deformations mixed together, then a comparison between result
of a posteriori compensation and those of non-compensation
are made, So as to investigate effect on compensatione Fi-
nally by applying practical block data, effect of a posteriori
compensation in application to practical materials is provede
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