Proceedings with Extended Abstracts (single PDF file) - Radio ...

Where dx/dt and dy/dt are the velocity projections of the target in the x and y planerespectively. The range of elevations and azimuths for the experiment lies between48 o o o≤ θ ≤ 53 , −15≤ φ ≤ 5 respectively, or in other words cosθ sinφ≤ 0. 18 and0.58≤ cosθcosφ≤ 0.67 . Figure 5 presents the correlation of the estimated range rates from theobservation and that of obtained from the model (4). The result shows very good agreementbetween observation and estimated values with the correlation coefficient near to 0.8.-15 Estimated cor=0.81-25-35-45-55Figure 4. Left plot display range time plot for astriation. Right plot is the counterpart of simplegeometry of quasi-point target’s plane motion at aconstant altitude with a fixed velocity.-65 -55 -45 -35 -25 -15ConclusionWe now summarize the three dimensional behaviors of the QP echoes revealed by theinterferometry observations. The echo patches were localized. These echoes drifting throughthe radar beam around 98 and 100 km altitudes. Although, there were four striations beingobserved by the radar at one time, but three-dimensional structures of the QP echoesdisplayed in different range gate as it is viewed in RTI plot revealed that they resided atapproximately constant altitude, and were shown at different region on the horizontal plane.So, the results suggest that the three dimensional behavior of the QP echoes frominterferometry data prefer to interpret as quasi-point target scatterers. Range rate estimationthrough the model also shows good agreement with observation.References:Farley, D.T., Ierkic, H.M., Fejer, B.G., Radar Interferometry: a new technique for studyingplasma turbulence in the ionosphere, J. Geophys. Res.,86, 1467-1472,1981.Hysell, D.L., and J.D. Burcham, The 30-MHz radar interferometer studies of midlatitude Eregion irregularities, J. Geophys. Res.,105, 12797-12812,2000.Larsen, M.F., A shear instability seeding mechanism for quasiperiodic radar echoes, J.Geophys. Res.,105, 24931-24940,2000.Tsunoda, R.T., S. Fukao, and M. Yamamoto, On the origin of qsasi-periodic radar backscatterfrom midlatitude sporadic E, Radio Sci., 29, 349-365,1994.Tsunoda, R.T., J.J. Buoncore, A. Saito, T. Kishimoto, S. Fukao, and M. Yamamoto, Firstobservations of quasiperiodic radar echoes from Standford, California, Geophys. Res.Lett., 26, 995-998,1999.Wang, C.Y. and Y.H. Chu, Interferometry investigations of blob-like sporadic E plasmairregularity using the Chung-Li VHF radar, J. Atmos. Solar-Terr. Phys.,63,123-133,2001.Woodman, R.T., M. Yamamoto, S. Fukao, Gravity wave modulation of gradient driftinstabilities in mid-latitude sporadic E irregularities, Geophys. Res. Lett., 18, 1197-1200,1991.Yamamoto, M.,S. Fukao, R.F. Woodman, T. Ogawa, T. Tsuda, and S. Kato, Midlatitude Eregion field-aligned irregularities observed with the MU radar, J. Geophys. Res.,96,15943-15949,1991.-65Figure 5. Correlation of the range rates usingobservation and model based estimation for tenstriations.97