http://nopr.niscpr.res.in/handle/123456789/37388 2026-10-10T23:52:44Z http://nopr.niscpr.res.in/handle/123456789/37953 Title: Dependence of Fading Frequency on the Characteristics of Ionospheric Irregularities Authors: Sastri, J. Hanumath; Rao, B. Ramachandra Abstract: A study has been made of the relationship between fading frequency and the parameters that describe the nature and movement of ionospheric it regularities responsible for fading. It is noticed that the fading frequency is directly correlated with true drift speed and random velocity, and inversely with the structure size. Page(s): 88-90 1973-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/37952 Title: Ionospheric Absorption on 2.4 MHz at Waltair Authors: Rao, D. N. Madhusudhana; Ramana, K. V. V. Abstract: Results of a preliminary investigation on the 2.4 MHz radio wave absorption in ionosphere using the Al technique are presented. It has been found that the diurnal variation parameter <i>n </i> (cos <img src='/image/spc_char/lembda.gif' border=0> index) has a wide range of values from 0.3 to 1.5 with a mean of 0.62 ±0.003 (p. e.). The cos <img src='/image/spc_char/lembda.gif' border=0> index <i>n </i> is found to have significant positive correlation with the Zurich sunspot number. The noon-time absorption values show large day-to-day variation and have a positive correlation with sunspot number. The seasonal variation of the monthly mean noon-time absorption indicates an increase in equinoctial months. Page(s): 86-88 1973-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/37951 Title: Attitude Determination of a Small Spinning Satellite Authors: Goel, P. S. Abstract: One magnetometer when placed in a spinning satellite in such a way that its axis makes an angle γ= tan-1<img src='http://www.niscair.res.in/jinfo/root2bar.gif' border=0> with the spin-axis gives successively three mutually independent components of the earth's magnetic field after each 120ᵒ rotation. This technique is utilized in determining the spin rate and the angle between the spin-axis and geomagnetic vector. This angle does not uniquely define the spin-axis in space but three such angles evaluated in successive orbits fix up the spin-axis and hence determine the attitude. By introducing one sun detector, the satellite attitude can be determined instantaneously by noting the magnetometer output at the time of a pulse from the sun detector. Page(s): 81-85 1973-03-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/37950 Title: Design of Back-Scatter Radar System at Thumba Authors: Jain, C. L.; Janardhanan, K. V.; Muralikrishna, P. Abstract: An indigenously developed coherent back-scatter radar operating at 54.95 MHz was installed at rhumba (8° 31' N; 76° 52' E; dip 0° 47' S) for carrying out systematic investigation of the electrojet irregularities of about 3 m vertical scale size. The system is, in principle, similar to that used at Jicamarca, Peru (11° 37' S; 76° 52' W; dip 1° N), which operates at 50 MHz. The correlation between scattered signal and variation in horizontal component of earth's magnetic field is also presented for a quiet day. Page(s): 76-80 1973-03-01T00:00:00Z