Extension of MF radar tidal measurements to E-region heights (95-125 km): Saskatoon (52°N, 107°W), Canada

1994 ◽  
Vol 12 (4) ◽  
pp. 333-341
Author(s):  
S. P. Namboothiri ◽  
A. H. Manson ◽  
C. E. Meek
Keyword(s):  
Radar Observations ◽  
Tidal Propagation ◽  
Radar Echoes ◽  
Tidal Data ◽  
E Region ◽  
Future Work ◽  
Mf Radar

Abstract. Efforts have been made to extend the MF radar tidal profiles to E-region heights. The totally reflected MF radar echoes from E-region heights during daytime are known to be group-retarded and the corresponding wind and tidal data will have associated height discrepancies. The estimation of the E-region real heights (Namboothiri et al., 1993), and the elimination of the data for which the group retardation is significant, are selected as the basic criteria to extend the tidal profiles to 100-125 km. The analysis of the quiet (Ap<19) days of the winter and summer seasons of 1988/89 shows that the tidal propagation continues to higher altitudes with some changes in their pattern, e.g. longer wavelengths, compared to that in the lower altitudes. Comparison with the model profiles shows some resemblance and some disagreements. The reliability of the MF radar tidal measurements of E-region heights and the propagation of tides in this region have been discussed in the light of existing theories and other experimental observations. It is concluded that, based on the initial studies with UHF and MF systems and within the limits of the available theories, the information on tides presented here for the 100-125 km region using the MF radar observations is useful. Suggestions for future work in this direction are also given.

scholarly journals Simultaneous VHF radar backscatter and ionosonde observations of low-latitude E region

2005 ◽  
Vol 23 (3) ◽  
pp. 773-779 ◽  
Author(s):  
A. K. Patra ◽  
S. Sripathi ◽  
P. B. Rao ◽  
K. S. V. Subbarao
Keyword(s):  
Low Latitude ◽  
Vhf Radar ◽  
Radar Echoes ◽  
First Results ◽  
E Region ◽  
Gradient Drift ◽  
Drift Instability ◽  
Relationship Of ◽  
The Relationship ◽  
Field Aligned Irregularities

Abstract. The first results of simultaneous observations made on the low-latitude field-aligned irregularities (FAI) using the MST radar located at Gadanki (13.5° N, 79.2° E, dip 12.5°) and the Es parameters using an ionosonde at a nearby station Sriharikota (13.7° N, 80.1° E, dip 12.6°) are presented. The observations show that while the height of the most intense radar echoes is below the virtual height of Es (h'Es) during daytime, it is found to be either below or above during nighttime. The strength of the FAI is better correlated with the top penetration frequency (ftEs) and the blanketing frequency (fbEs) during the night (r=0.4 in both cases) as compared to the day (r=0.35 and -0.04, respectively). Furthermore, the signal strength of FAI is reasonably correlated with (ftEs-fbEs) during daytime (r=0.59) while very poorly correlated during nighttime (r=0.18). While the radar observations in general appear to have characteristics close to that of mid-latitudes, the relationship of these with the Es parameters are poorer than that of mid-latitudes. The observations reported here, nevertheless, are quite consistent with the expectations based on the gradient drift instability mechanism.

scholarly journals Morphological study of the field-aligned E-layer irregularities observed by the Gadanki VHF radar

2004 ◽  
Vol 22 (11) ◽  
pp. 3799-3804 ◽  
Author(s):  
C. J. Pan ◽  
P. B. Rao
Keyword(s):  
Geomagnetic Latitude ◽  
Spectral Width ◽  
Statistical Characteristics ◽  
Low Latitude ◽  
Vhf Radar ◽  
Lower Altitude ◽  
Radar Echoes ◽  
E Region ◽  
Sporadic E ◽  
Total Observation

Abstract. We report on the field-aligned irregularities observed in the low-latitude sporadic E-layer (Es) with the Gadanki (13.5° N, 79.2° E; geomagnetic latitude 6.3° N) VHF radar. The radar was operated intermittently for 15 days during the summer months in 1998 and 1999, for both daytime and nighttime observation. The total observation periods are 161h for the nighttime and 68h for the daytime. The observations were used to study the percentage of occurrence of the E-region echoes for both daytime and nighttime. The statistical characteristics of the mean radial velocity and spectral width are presented for three cases based on the echo occurrence characteristics and the altitude of observations (from 90 to 140km ranges), namely, the lower E-region daytime (90-110km), the lower E-region nighttime (90-105km) and the upper E-region nighttime (105-140km) echoes. The results are compared with that of Piura, a low-latitude station located at about the same geomagnetic latitude, but to the south of the equator. By comparing the behaviors of the lower E-region radar echoes of the summer months between Gadanki and Piura, we find that the lower altitude echoes below about 100km are rarely reported in Piura but commonly seen in Gadanki. Features of the nighttime echoes observed by these two radars are quite similar but daytime FAI echoes are again seldom detected by Piura.

scholarly journals Radar observations of the moon at 10-cm wavelength

1959 ◽  
Vol 9 ◽  
pp. 13-18 ◽  
Author(s):  
J. S. Hey ◽  
V. A. Hughes
Keyword(s):  
Radio Telescope ◽  
Peak Power ◽  
Pulse Length ◽  
Noise Factor ◽  
The Moon ◽  
Servo Drive ◽  
Radar Observations ◽  
Radar Echoes ◽  
Recurrence Frequency ◽  
Initial Results

This note describes some of the initial results derived from observations of radar echoes from the moon obtained at 10-cm wavelength at the Royal Radar Establishment, Malvern. The radar, which has been described elsewhere [1], has a transmitter of 2 megawatts peak power with a pulse length of 5 microseconds and a pulse recurrence frequency of 260 per second. The receiver is of conventional design and has a bandwidth of 500 kc/s and a noise factor of 7.5. The aerial used is the 45-foot diameter radio telescope shown in Fig. 1. The telescope is controlled from a mechanical computer that converts the lunar coordinates into azimuth and elevation, which are then fed into a servo drive.

Lower E-region MF radar spaced antenna measurements over magnetic equator

2002 ◽  
Vol 64 (12-14) ◽  
pp. 1445-1453 ◽  
Author(s):  
T.K Ramkumar ◽  
S Gurubaran ◽  
R Rajaram
Keyword(s):  
Magnetic Equator ◽  
Antenna Measurements ◽  
E Region ◽  
Mf Radar

Extension of MF radar tidal measurements to E-region heights (95–125 km): Saskatoon (52°N, 107°W), Canada

1994 ◽  
Vol 12 (4) ◽  
pp. 333
Author(s):  
S. P. Namboothiri ◽  
A. H. Manson ◽  
C. E. Meek
Keyword(s):  
E Region ◽  
Mf Radar

scholarly journals MU Radar observations of kilometer-scale waves in the midlatitude lower E-region

2000 ◽  
Vol 27 (22) ◽  
pp. 3667-3670 ◽  
Author(s):  
P. B. Rao ◽  
M. Yamamoto ◽  
A. Uchida ◽  
I. Hassenpflug ◽  
S. Fukao
Keyword(s):  
Radar Observations ◽  
Mu Radar ◽  
E Region

scholarly journals Amplitude enhancements in Antarctic MF radar echoes

2000 ◽  
Vol 105 (D21) ◽  
pp. 26683-26693 ◽  
Author(s):  
D. J. Murphy ◽  
R. A. Vincent
Keyword(s):  
Radar Echoes ◽  
Mf Radar

Evidence of kilometer-scale waves in the lower E region from high resolution VHF radar observations over Gadanki

2002 ◽  
Vol 29 (10) ◽  
pp. 137-1-137-4 ◽  
Author(s):  
A. K. Patra ◽  
S. Sripathi ◽  
V. Siva Kumar ◽  
P. B. Rao
Keyword(s):  
High Resolution ◽  
Vhf Radar ◽  
Radar Observations ◽  
E Region
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