Abstract
Users themselves wish to take aerial photographs by means of easy handling and cheap system from several hundred meters high, for environmental study.
Chartered flight for aerial survey used to be expensive, and also very difficult for acquisition at any time and at any frequency. Unmanned system such as radio control aircraft or helicopter needs not only professional skills in operation but also has limitations in confirming the coverage or the looking angle.
The objectives of the study are to develop a kite balloon camera system with 35 millimeter camera of gyro control, which allows to obtain stereo photographs from up to 800 meters, and to establish the methodology for three dimensional measurement and remote sensing.
As the results of the experimental study in Futtsu, Chiba, stereo pairs of aerial photographs with off nadir angle of ±15 degree were successfully taken from 800 meters high under the condition of strong wind velocity.
Analytical stereo photogrammetry can be applied for three dimensional photogrammetry by non-metric camera when the camera is calibrated in advance. The result of the experiment showed that the accuracy of three dimensional measurement was ±8 centimeters in position, ±30 centimeters in height (0.33 permil of flight height) in the case of 800 meters flight height and the focal length of 28 millimeters.
Required volume of helium gas was 7 cubic meters, which costed 18, 900 Japanese Yen. The cost of the kite balloon camera system was 629, 000 Yen in total. A wagon type car to carry 1.37 meters length helium vessel and three operators at minimum are required for this system.
