Implementing and Characterizing Real-time Broadband RFI Excision for the GMRT Wideband Backend

The Giant Metrewave Radio Telescope (GMRT) is being upgraded to increase the receiver sensitivity. This makes the receiver more susceptible to man-made Radio Frequency Interference (RFI). To improve the receiver performance in presence of RFI, real-time RFI excision (filtering) is incorporated in the GMRT wideband backend (GWB). The RFI filtering system is implemented on FPGA and CPU-GPU platforms to detect and remove broadband and narrowband RFI. The RFI is detected using a threshold-based technique where the threshold is computed using Median Absolute Deviation (MAD) estimator. The filtering is carried out by replacing the RFI samples by either noise samples or constant value or threshold. This paper describes the status of the real-time broadband RFI excision system in the wideband receiver chain of the upgraded GMRT (uGMRT). The test methodology for carrying out various tests to demonstrate the performance of broadband RFI excision at the system level and on radio astronomical imaging experiments are also described.Comment: 7 pages, 7 figure

ExoMars Schiaparelli Direct-to-Earth Observation using GMRT

During the ExoMars Schiaparelli separation event on 16 October 2016 and Entry, Descent, and Landing (EDL) events 3 days later, the Giant Metrewave Radio Telescope (GMRT) near Pune, India, was used to directly observe UHF transmissions from the Schiaparelli lander as they arrive at Earth. The Doppler shift of the carrier frequency was measured and used as a diagnostic to identify key events during EDL. This signal detection at GMRT was the only real‐time aliveness indicator to European Space Agency mission operations during the critical EDL stage of the mission

Effect of major nutrients on yield of ginger (Zingiber officinale Rose.) intercropped in coconut garden

The effect of different levels of nitrogen, phosphorus and potassium on the yield of ginger (Zingiber officinale Rosc.) grown as an intercrop in a coconut garden was studied in a field experiment conducted at Coconut Research Station, Balaramapuram, Thiruvanathapuram, Kerala. Significant increases in leaf production, leaf area index and dry matter production, crop growth rate and uptake of nutrients were resulted from higher dose of fertilizers. Fertilizer recommendation for ginger grown under open condition (N:P:K @.75:50:50 kg ha-1) is insufficient for ginger intercropped in coconut gardens. A higher fertilizer dose of N:P:K @ 150:100:100 kg ha-1 is necessary for increasing the yield of ginger grown as an intercrop in coconut garden. &nbsp

Influence of shade regimes on yield and quality of ginger (Zingiber officinale Rosc.)

The effect of different levels of shade on yield and quality of ginger (Zingiber officinale Rosc.) was studied during two seasons at Coconut Research Station, Thiruvananthapuram, Kerala Agricultural University, Kerala. The shade levels 20 and 40 per cent were favourable for obtaining higher dry ginger yield. Volatile oil content showed an increasing trend with increasing levels of shade. Maximum NVEE was recorded in the plants grown under 20 and 40 per cent shade levels. Higher starch content was observed in plants grown under 20 per cent shade level. Crude fibre content gradually reduced as the intensity of shade increased. The results indicate the possibility of utilizing existing shaded situations in coconut gardens and under other perennial crops for the production of ginger. &nbsp

Effect of major nutrients on yield of ginger (Zingiber officinale Rose.) intercropped in coconut garden

The effect of different levels of nitrogen, phosphorus and potassium on the yield of ginger (Zingiber officinale Rosc.) grown as an intercrop in a coconut garden was studied in a field experiment conducted at Coconut Research Station, Balaramapuram, Thiruvanathapuram, Kerala. Significant increases in leaf production, leaf area index and dry matter production, crop growth rate and uptake of nutrients were resulted from higher dose of fertilizers. Fertilizer recommendation for ginger grown under open condition (N:P:K @.75:50:50 kg ha-1) is insufficient for ginger intercropped in coconut gardens. A higher fertilizer dose of N:P:K @ 150:100:100 kg ha-1 is necessary for increasing the yield of ginger grown as an intercrop in coconut garden. &nbsp

CORRELATION AND PATH COEFFICIENT ANALYSIS IN LINSEED (LINUM USITATISSIMUM L.)

The present study was conducted on variability, correlation and path coefficient analysis for yield and yield contributing characters in linseed. The highest genotypic coefficient of variation was observed for 1000 seed weight (29.48) and high heritability coupled with high genetic advance was observed for 1000 seed weight (0.99 and 60.45) and seed yield (0.85 and 35.40). The results of phenotypic and genotypic correlation analysis revealed that number of capsules plant-1 (0.797 and 0.704), was significantly and positively correlated with seed yield and plant height (0.2 and 0.192) and technical plant height (0.204 and 0.198) was positively correlated with seed yield in present material. Path analysis indicated that number of capsules plant-1 (0.7615) exhibited high direct positive effect on seed yield signifying the importance of this trait while selecting for improvement of seed yield of linseed

Influence of shade regimes on yield and quality of ginger (Zingiber officinale Rosc.)

The effect of different levels of shade on yield and quality of ginger (Zingiber officinale Rosc.) was studied during two seasons at Coconut Research Station, Thiruvananthapuram, Kerala Agricultural University, Kerala. The shade levels 20 and 40 per cent were favourable for obtaining higher dry ginger yield. Volatile oil content showed an increasing trend with increasing levels of shade. Maximum NVEE was recorded in the plants grown under 20 and 40 per cent shade levels. Higher starch content was observed in plants grown under 20 per cent shade level. Crude fibre content gradually reduced as the intensity of shade increased. The results indicate the possibility of utilizing existing shaded situations in coconut gardens and under other perennial crops for the production of ginger. &nbsp

Rice area mapping in Palakkad district of Kerala using Sentinel-2 data and Geographic information system technique

Proper calculation of rice cultivation area well before harvest is critical for projecting rice yields and developing policies to assure food security. This research looks at how Remote Sensing (RS) and Geographic Information System (GIS) can be used to map rice fields in Palakkad district of Kerala. The area was delineated using three multi-temporal cloud free Sentinel-2 data with 10 m spatial resolution, matching to crop's reproductive stage during mundakan season (September-October to December-January), 2020-21. To make classification easier, the administrative boundary of district was placed over the mosaicked image. The rice acreage estimation and land use classification of the major rice tract of Palakkad district comprising five blocks was done using Iterative Self-Organisation Data Analysis Technique (ISODATA) unsupervised classification provision in ArcGIS 10.1 software, employing False Colour Composite (FCC) including Blue (B2), Green (B3), Red (B4) and Near-infrared (B8) Bands of Sentinel-2 images. The classification accuracy was determined by locating a total of 60 validation points throughout the district, comprising 30 rice and 30 non-rice points. The total estimated area was 24742.76 ha, with an average accuracy of 88.33% and kappa coefficient 0.766 in five blocks of Palakkad district. The information generated will be helpful in assessing the anticipated production as well as the water demand of the rice fields

Mushroom Cultivation MOOC at Kerala Agricultural University: Garrett Ranking Analysis of Constraints to Enhance Online Agriculture Learning

Participants in this extensive Massive Open Online Course (MOOC) on mushroom cultivation will gain a wealth of knowledge and useful skills necessary for cultivating a wide variety of mushrooms. In this study, the Center for e-learning at Kerala Agriculture University will analyse the barriers to mushroom growing as part of a MOOC. 30 participants in the MOOC course were chosen at random to participate in the study as responses. Using the specified sampling size and data collection methodology, an ex post facto research design was employed for the study. The requirements in the MOOC course were prioritized using the Garrett ranking technique after the data were statistically analysed. Results revealed that 55.06 per cent of the respondents have the economic constraint that is the power/ electricity usage costs more to them, of the technological challenges encountered, interacting with the resource person less frequently comes in the rank first with 60.13 per cent, the biggest personal challenge is developing skill-oriented knowledge, which is difficult and it has been ranked first with 67 per cent, Personal commitments, such as employment, family duties, health concerns etc., ranks first with 62.53 in terms of situational limitations and 66 percent of the respondents rranked first that there is more number of theory classes with minimum hands-on experience in psychological challenge

ExoMars Schiaparelli Direct-to-Earth Observation using GMRT

During the ExoMars Schiaparelli separation event on 16 October 2016 and Entry, Descent, and Landing (EDL) events 3 days later, the Giant Metrewave Radio Telescope (GMRT) near Pune, India, was used to directly observe UHF transmissions from the Schiaparelli lander as they arrive at Earth. The Doppler shift of the carrier frequency was measured and used as a diagnostic to identify key events during EDL. This signal detection at GMRT was the only real‐time aliveness indicator to European Space Agency mission operations during the critical EDL stage of the mission