The Mathematic Model and Application of Satellite Phototopography
1 .The development of Satellite Phototopography
In twenty first century ,The Topography are developing to a new stage of Satellite
Phototopography and Aerophototopography .
The Global positioning system are used for positioning of the sensor or antenna position on orbit
with required accuracy of topographic control measurement, and the Inertial Measurement unit
and stellar observation are used for determination of the direction of earth observation, So that
adopting Satellite Phototopography, The topographic surveying and mapping including
stereomapping , DEM measurement , orthophotomapping could be conducted with a few control
points measurement on the field.
SPOT-5 are an Typical phototopographic satellite: HRG collected image with 2.5 meter resolution
can be used to orthophoto mapping and detail mapping in scale 1:50000 and 25000; Through
forward and backward vision, HRS can collect the topographic data and DEM data for
stereomapping in range 600 km_by_ 120 km . Besides of spatial resolution increased to 0.7
meter, Planning SPOT Pleiades-HR have the capability to collect stereo and tri-stereo imagery for
large image coverage through lateral vision and forward/backward vision, as well the capability
for surveying and mapping along a river, border and coast line.
The Satellite Phototopography is developing which has the new characteristic as following :
For Satellite Phototopography, The instantaneous satellite position on orbit will be a station
from which the forward intersection are carried on, So, the position of station should be computed
by using satellite geodesy method and with the accuracy topographic control survey required.
With high accuracy time and stable velocity, for a temporal period, Satellite move along the
orbit a step correspondence to spatial resolution.
Either lateral vision or forward/backward vision along orbit the visual direction of sensor are
determined by attitude angle. Therefore the grouped stellar observation / IMU system are
important part of satellite phototopographic system.
Along with the development of spatial and temporal measurement technology, satellite
phototopographic survey could be conducted with only a few control measurements on the
ground.
