The National Metrology Institute of India and A Premier Research Laboratory in the Field of Physical Sciences
Radio Physics and Applications

Comparison between IRI predictions and digital ionosonde measurements of hmF2 at New Delhi during low and moderate solar activity

The diurnal and seasonal variations of height of the peak electron density of the F2-layer (hmF2) derived from digital ionosonde measurements at a low–middle-latitude station, New Delhi have been derived. Diurnal and seasonal variations of hmF2 are examined and comparisons of the observations are made with the predictions of the International Reference Ionosphere (IRI-2001) model.

Network of Digital Ionosonde System, GPS and Tomographic Receivers

A network as shown in Fig. 6.2 of Digital Ionosonde Systems (Delhi & Bhopal), dual frequency GPS receivers (Delhi, Trivandrum) and NWRA Tomographic Receivers (Delhi and Bhopal) for having extensive measurements of foF2, hmF2, TEC and VHF, UHF & L-band Scintillation for developing Ionospheric models has been established. The GPS receivers are for TEC and L-band Scintillation monitoring, Tomographic Receivers for 150 and 400 MHz scintillation, latitudinal TEC profile for producing Tomographic Images and Digital ionosonde for continuous monitoring of different ionospheric layers etc.

Prediction of maximum amplitude and shape of Sunspot Cycle number 24 for different applications - Revised and updated

The characteristics of the 11-year solar cycle were of mere academic curiosity; but in the present satellite age, the strength of the solar cycle makes a huge difference to satellite operators, who plan their launches many years in advance. Each solar peak heats and expands the outer atmosphere, which in turn increases the drag on satellites, especially those in low-Earth orbits. Hence, satellite planners decide their missions and adjust orbital heights to take advantage of weak solar activity, if possible.