An Overview of the Frequency Activities at National Physical Laboratory, New Delhi, India

1981 ◽  
Vol 27 (10) ◽  
pp. 350-354
Author(s):  
B.S. Mathur
Keyword(s):  
National Physical Laboratory ◽  
New Delhi ◽  
Physical Laboratory

Josephson voltage standard at National Physical Laboratory, New Delhi

Pramana ◽  
1987 ◽  
Vol 28 (5) ◽  
pp. 517-527 ◽  
Author(s):  
A K Gupta ◽  
N S Natarajan ◽  
V S Tomar ◽  
N D Kataria ◽  
V K Batra ◽  
...  
Keyword(s):  
National Physical Laboratory ◽  
New Delhi ◽  
Voltage Standard ◽  
Physical Laboratory

scholarly journals Radio refractivity observations over the oceans using airborne microwave refractometer in tropics

MAUSAM ◽  
2021 ◽  
Vol 42 (2) ◽  
pp. 183-186
Author(s):  
S. B. S. S. SARMA
Keyword(s):  
Coastal Waters ◽  
Layer Structure ◽  
National Physical Laboratory ◽  
New Delhi ◽  
Physical Laboratory ◽  
Antisubmarine Warfare ◽  
Time Basis ◽  
Anomalous Propagation ◽  
First Time ◽  
Marine Layer

The coastal waters of Indian sub -continent do not have reliable measurements of fine structure of radio refractivity especially in near real-time basis needed to mitigate the effects of anomalous propagation for the defence communications as well as for antisubmarine warfare. This programme was designed to document the radio refractive layer structure and variations of the marine layer in tropical waters of India. The paper describes the above observations taken using the airborne microwave refractometer developed by the author at National Physical Laboratory, New Delhi. Typical observations taken (for the first time in India) under normal and anomalous propagation conditions are presented and the results are compared with the special shipborne observations made under MONEX operation over the coastal waters of India.

scholarly journals Detection of Kelvin-Helmholtz billows over the National Capital Region of India using SODAR

2021 ◽  
Author(s):  
Nishant Kumar ◽  
Kirti Soni ◽  
Ravinder Agarwal
Keyword(s):  
Boundary Layer ◽  
National Physical Laboratory ◽  
New Delhi ◽  
National Capital Region ◽  
Resolution Limit ◽  
Capital Region ◽  
Physical Laboratory ◽  
Sound Detection ◽  
National Capital ◽  
Remote Sensing Methods

Abstract. Kelvin-Helmholtz billows (KHB) have been investigated in the Atmospheric Boundary layer (ABL) using Mono-static SODAR (Sound Detection And Ranging) designed and developed by CSIR-National Physical Laboratory, New Delhi over the capital region Delhi of India. KH billows are a primary cause of mixing in stably stratified conditions and hence have been studied widely by researchers by using ground-based and remote sensing methods. About ninety cases of KHBs observed in SODAR echograms from March 2019 to November 2019 in the ABL. Trains of K-H billows lasting from thirty minutes to various minutes were frequently detected in the lower portion of the troposphere (ABL), creating in a statically stable ABL. Most recognised billows are round the resolution limit of SODAR. Additionally, several of the cases contain billows with extremely varied amplitudes and shapes. The most significant number of episodes observed in the October months were related with the morning growth of the inversion.

scholarly journals 75th Foundation Day of CSIR-National Physical Laboratory: Celebration of Achievements in Metrology for National Growth

MAPAN ◽  
2021 ◽  
Author(s):  
Sanjay Yadav ◽  
Goutam Mandal ◽  
V. K. Jaiswal ◽  
D. D. Shivagan ◽  
D. K. Aswal
Keyword(s):  
National Physical Laboratory ◽  
Physical Laboratory ◽  
National Growth
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