Principles of Modern Radar - Volume 2 1891121537

8.12 Problems 397[74] Romeiser, R. and Hirsch, O., “Possibilities and Limitations of Current Measurements byAirborne and Spaceborne Along-Track Interferometric SAR,” in Proceedings of the IEEEInternational Geoscience and Remote Sensing Symposium, vol. 1, pp. 575–577, 2001.[75] Wikipedia. “Northrop Grumman E-8 Joint STARS.” Available at http://en.wikipedia.org/wiki/Northrop Grumman E-8 Joint STARS.[76] Gens, R. and Vangenderen, J.L., “SAR Interferometry—Issues, Techniques, Applications,”International Journal of Remote Sensing, vol. 17, no. 10, pp. 1803–1835, 1996.[77] Massonnet, D. and Feigl, K.L., “Radar Interferometry and Its Application to Changes in theEarth’s Surface,” Rev. Geophys., vol. 36, no. 4, pp. 441–500, 1998.[78] Rogers, A.E.E. and Ingalls, R.P., “Venus: Mapping the Surface Reflectivity by Radar Interferometry,”Science, vol. 165, pp. 797–799, 1969.[79] Zisk, S.H., “A New Earth-Based Radar Technique for the Measurement of Lunar Topography,”Moon, vol. 4, pp. 296–300, 1972.[80] Graham, L.C., “Synthetic Interferometric Radar for Topographic Mapping,” Proceedings ofthe IEEE, vol. 62, pp. 763–768, June 1974.[81] Zebker, H.A. and Goldstein, R.M., “Topographic Mapping from Interferometric SAR Observations,”Journal of Geophysics Res., vol. 91, pp. 4993–4999, 1986.[82] Li, F. and Goldstein, R.M., “Studies of Multibaseline Spaceborne Interferometric SyntheticAperture Radars,” IEEE Transactions on Geoscience and Remote Sensing, vol. 28, pp. 88–97,1990.[83] Richman, D., “Three Dimensional, Azimuth-Correcting Mapping Radar,” U.S. patent4,321,601, March 23, 1982.[84] Eineder, M. et al., “Spaceborne Spotlight SAR Interferometry with TerraSAR-X,” IEEE Transactionson Geoscience and Remote Sensing, vol. 47, no. 5, pp. 1524–1535, May 2009.8.12 PROBLEMS1. Compute the approximate number of posts (points at which an elevation measurementis specified) required to cover a region measuring 10 km × 10 km for a DEM at DTEDlevels 0 through 5 and HRE levels 6 through 8.2. Consider the sensor-scatterer geometry shown in Figure 8-4. Assume the center ofthe sensor baseline is at altitude H = 2000 m, the ground range y 1 = 5100 m, and theelevation of scatterer P 1 is h = 73.6 m. Also assume a sensor baseline length B = 3m and a tilt angle β = 90 ◦ (vertically stacked sensors). Compute the depression angleψ 1 from the baseline center to P 1 . Next, compute the ranges R a and R b from eachsensor to P 1 . Then compute R and δR from R a and R b . Finally, use equations (8.5)and (8.2) to estimate ψ 1 and h and the percentage error in the estimate of each.3. For the geometry of problem 2, compute the ground range y 0 at which the scattererP 1 will be imaged.4. Continuing with the geometry of problem 2, the IPD measured at ground range y 0 fora 10 GHz radar (λ = 3 cm) with independent transmitters (p = 2) is φ ab = 444.0425radians. Use InSAR DEM algorithm 1 to estimate the height of the scatterer imaged aty 0 and its actual ground range; that is, estimate y 1 and ĥ (y 1 ). Compute the percentageerror in each.