yrdinates
brations.
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oA
71
|
44
|
305
ratory
tation
L|
ib
|
417
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073
„503
oratory
tion tests in
surized twin
re 2.
s maintained
o. Results of
Dean Merchant
Figure 2 The NOAA Pressurized Cessna Citation Preparing to Fly the Madison Ranges
EAST NORTH UP
in situ lab in situ lab in situ lab
bias -0.150 -0.123 -0.265 -0.051 0.020 0.806
std. dev. | about 0.324 0.648 0.337 1.145 0.119 0.229
mean
std. dev. | about 0.367 0.663 0.455 1.146 0.121 0.958
GPS
Table 3. Coordinate Discrepancies Between GPS and Single-Photo Resections Based on /n Situ and Laboratory
Calibrations for Four Photos at 5800 Meters Above Ground [meters]
4. CONCLUSION
This investigation is intended to assess the influence of the operational environment on spatial coordinates computed
photogrammetrically to those determined by GPS. For this purpose, single photo resected coordinates from in situ
calibrations were compared to laboratory based calibrations. All data was based on imagery collected over controlled
test ranges and under operational circumstances. Both ported and pressurized aircraft were investigated. Bias errors
in elevation of 1.6 meters correspnding to one part in 730 of the flight height were observed.
Itis concluded that calibrations based on data from operational conditions are subject to substantially smaller systematic
error than those based on traditional laboratory methods.
Further investigations are warranted to clearly identify causes of this bias that is primarily in elevation. It is further
concluded that environmental factors play a strong role in the calibration of added airborne sensors and the relative
spatial relationships within any airborne system of sensors.
ACKNOWLEDGMENTS
Many individuals made important contributions during the course of this investigation. At ODOT, of particular note
are James Crowl, Ed Kroman and Milan Kofron for their enthusiasm and continued support. The direct involvement
and interest of Capt. Lewis Lapine and James Lucas [NGS] and Donald Light [USGS], made the high-altitude project
possible and enjoyable.
International Archives of Photogrammetry and Remote Sensing. Vol, XXXIII, Part B3. Amsterdam 2000.
Un
2
Un