Prasanna Mahavarkar | Indian Institute of Geomagnetism (original) (raw)

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Papers by Prasanna Mahavarkar

Research paper thumbnail of Designing a Sky-Scanning Fabry-Perot Interferometer System with a Large Size Integrating Sphere

Research paper thumbnail of Commissioning of the multiparametric geophysical observatory at Shoal Bay, South Andaman and the preliminary results

Research paper thumbnail of Tri Axial Square Helmholtz Coil system at the Alibag Magnetic Observatory: Upgraded to Magnetic Sensor calibration facility

A Tri Axial Square Helmholtz Coil system for the study of palaeomagnetic studies was successfully... more A Tri Axial Square Helmholtz Coil system for the study of palaeomagnetic studies was successfully commissioned at the Alibag magnetic observatory in the year 1985. This system was used for few years after which the system encountered technical problems with the control unit. Rectification of the same could not be undertaken as the information document related to this system was not available and as a result the said system had been lying in an unused state for a long time until 2015 when the system was re-commissioned and upgraded as a test facility for calibrating the magnetometer sensors. We have upgraded the system with a constant current source and a data logging unit. Both these units have been designed and developed in the institute laboratory. Also re-measurements of the existing system have been made thoroughly. The upgraded system is semi automatic, enabling non-specialists to operate it after a brief period of instruction. This facility is now in broad use for the parent institute and external institutions to calibrate their magnetometers and also serves as a national facility. Here the design of this system with the calibration results for the space borne fluxgate magnetometers is presented.

Research paper thumbnail of Tri-axial square Helmholtz coil system at the Alibag Magnetic Observatory: upgraded to a magnetic sensor calibration facility

Geoscientific Instrumentation, Methods and Data Systems

A tri-axial square Helmholtz coil system for the study of palaeomagnetic studies, manufactured by... more A tri-axial square Helmholtz coil system for the study of palaeomagnetic studies, manufactured by GEO-FYZIKA (former Czechoslovakia), was successfully commissioned at the Alibag Magnetic Observatory (IAGA code: ABG) in the year 1985. This system was used for a few years, after which the system encountered technical problems with the control unit. Rectification of the unit could not be undertaken, as the information document related to this system was not available, and as a result the system had been lying in an unused state for a long time, until 2015, when the system was recommissioned and upgraded to a test facility for calibrating the magnetometer sensors. We have upgraded the system with a constant current source and a data-logging unit. Both of these units have been designed and developed in the institute laboratory. Also, re-measurements of the existing system have been made thoroughly. The upgraded system is semi-automatic, enabling non-specialists to operate it after a brief period of instruction. This facility is now widely used at the parent institute and external institutions to calibrate magnetometers and it also serves as a national facility. Here the design of this system with the calibration results for the space-borne fluxgate magnetometers is presented.

Research paper thumbnail of A high-altitude balloon experiment to probe stratospheric electric fields from low latitudes

Annales Geophysicae, 2017

The Earth's electrical environment hosts a giant electrical circuit, often referred to as the... more The Earth's electrical environment hosts a giant electrical circuit, often referred to as the global electric circuit (GEC), linking the various sources of electrical generators located in the lower atmosphere, the ionosphere and the magnetosphere. The middle atmosphere (stratosphere and mesosphere) has been traditionally believed to be passively transmitting electric fields generated elsewhere. Some observations have reported anomalously large electric fields at these altitudes, and the scientific community has had to revisit the earlier hypothesis time and again. At stratospheric altitudes and especially at low latitudes, horizontal electric fields are believed to be of ionospheric origin. Though measurements of these fields from a balloon platform are challenging because of their small magnitudes (around a few mV m<sup>−1</sup>), a suitably designed long-duration balloon experiment capable of detecting such small fields can provide useful information on the time e...

Research paper thumbnail of Designing a Sky-Scanning Fabry-Perot Interferometer System with a Large Size Integrating Sphere

Research paper thumbnail of Commissioning of the multiparametric geophysical observatory at Shoal Bay, South Andaman and the preliminary results

Research paper thumbnail of Tri Axial Square Helmholtz Coil system at the Alibag Magnetic Observatory: Upgraded to Magnetic Sensor calibration facility

A Tri Axial Square Helmholtz Coil system for the study of palaeomagnetic studies was successfully... more A Tri Axial Square Helmholtz Coil system for the study of palaeomagnetic studies was successfully commissioned at the Alibag magnetic observatory in the year 1985. This system was used for few years after which the system encountered technical problems with the control unit. Rectification of the same could not be undertaken as the information document related to this system was not available and as a result the said system had been lying in an unused state for a long time until 2015 when the system was re-commissioned and upgraded as a test facility for calibrating the magnetometer sensors. We have upgraded the system with a constant current source and a data logging unit. Both these units have been designed and developed in the institute laboratory. Also re-measurements of the existing system have been made thoroughly. The upgraded system is semi automatic, enabling non-specialists to operate it after a brief period of instruction. This facility is now in broad use for the parent institute and external institutions to calibrate their magnetometers and also serves as a national facility. Here the design of this system with the calibration results for the space borne fluxgate magnetometers is presented.

Research paper thumbnail of Tri-axial square Helmholtz coil system at the Alibag Magnetic Observatory: upgraded to a magnetic sensor calibration facility

Geoscientific Instrumentation, Methods and Data Systems

A tri-axial square Helmholtz coil system for the study of palaeomagnetic studies, manufactured by... more A tri-axial square Helmholtz coil system for the study of palaeomagnetic studies, manufactured by GEO-FYZIKA (former Czechoslovakia), was successfully commissioned at the Alibag Magnetic Observatory (IAGA code: ABG) in the year 1985. This system was used for a few years, after which the system encountered technical problems with the control unit. Rectification of the unit could not be undertaken, as the information document related to this system was not available, and as a result the system had been lying in an unused state for a long time, until 2015, when the system was recommissioned and upgraded to a test facility for calibrating the magnetometer sensors. We have upgraded the system with a constant current source and a data-logging unit. Both of these units have been designed and developed in the institute laboratory. Also, re-measurements of the existing system have been made thoroughly. The upgraded system is semi-automatic, enabling non-specialists to operate it after a brief period of instruction. This facility is now widely used at the parent institute and external institutions to calibrate magnetometers and it also serves as a national facility. Here the design of this system with the calibration results for the space-borne fluxgate magnetometers is presented.

Research paper thumbnail of A high-altitude balloon experiment to probe stratospheric electric fields from low latitudes

Annales Geophysicae, 2017

The Earth's electrical environment hosts a giant electrical circuit, often referred to as the... more The Earth's electrical environment hosts a giant electrical circuit, often referred to as the global electric circuit (GEC), linking the various sources of electrical generators located in the lower atmosphere, the ionosphere and the magnetosphere. The middle atmosphere (stratosphere and mesosphere) has been traditionally believed to be passively transmitting electric fields generated elsewhere. Some observations have reported anomalously large electric fields at these altitudes, and the scientific community has had to revisit the earlier hypothesis time and again. At stratospheric altitudes and especially at low latitudes, horizontal electric fields are believed to be of ionospheric origin. Though measurements of these fields from a balloon platform are challenging because of their small magnitudes (around a few mV m<sup>−1</sup>), a suitably designed long-duration balloon experiment capable of detecting such small fields can provide useful information on the time e...

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