• Korean Journal of Remote Sensing
• /
• v.24 no.3
• /
• pp.223-233
• /
• 2008

In the mid 90's, the U.S. government released images acquired by the first generation of photo reconnaissance satellite missions between 1960 and 1972. The Declassified Intelligent Satellite Photographs (DISP) from the Corona mission are of high quality with an astounding ground resolution of about 2 m. The KH-4A panoramic camera system employed a scan angle of $70^{\circ}$ that produces film strips with a dimension of $55\;mm\;{\times}\;757\;mm$. Since GPS/INS did not exist at the time of data acquisition, the exterior orientation must be established in the traditional way by using control information and the interior orientation of the camera. Detailed information about the camera is not available, however. For reconstructing points in object space from DISP imagery to an accuracy that is comparable to high resolution (a few meters), a precise camera model is essential. This paper is concerned with the derivation of a rigorous mathematical model for the KH-4A/B panoramic camera. The proposed model is compared with generic sensor models, such as affine transformation and rational functions. The paper concludes with experimental results concerning the precision of reconstructed points in object space. The rigorous mathematical panoramic camera model for the KH-4A camera system is based on extended collinearity equations assuming that the satellite trajectory during one scan is smooth and the attitude remains unchanged. As a result, the collinearity equations express the perspective center as a function of the scan time. With the known satellite velocity this will translate into a shift along-track. Therefore, the exterior orientation contains seven parameters to be estimated. The reconstruction of object points can now be performed with the exterior orientation parameters, either by intersecting bundle rays with a known surface or by using the stereoscopic KH-4A arrangement with fore and aft cameras mounted an angle of $30^{\circ}$.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.51 no.1
• /
• pp.31-38
• /
• 2002

We measured a 3-dimensional images of the light emitted from plasma display panel(PDP) by using newly proposed scanned point detecting system. In the panel without phosphor, as we scan from the rear glass to the front glass, the detected light intensity increases and the light intensity detected in the inside edge of the ITO electrodes shows the stronger intensity than others. The light intensity detected between the barrier ribs shows the largest value of brightness. Also, as the sustain voltage increases, the detected light intensity increases. In the panel with phosphor, the intensity of light detected at barrier rib shows the stronger light intensity than rear plate. Therefore, the phosphor of barrier rib is very important. From these results the 3-dimensional measurement is necessary to understand exactly the discharge phenomenon in the PDP cell.