Informatics Publishing Limited

Deepa Parashar ¹, Ankush Kumar ¹, N.P. Aditya ², Ramachandra Murthy Rayasa ¹

Affiliations
1 I.S.F. College of Pharmacy, Ferozpur, G.T. Road, Moga, Punjab
2 Food Nanotechnology Laboratory, Department of Food science and Technology, Sejong University, Seoul

Abstract

In the present investigation a simple, rapid and accurate method for the simultaneous estimation of artemether (ART) and lumefantrine (LUM) was developed using derivative spectroscopic technique. To avoid the overlapping of ART and LUM in zero order spectra, first order spectrum was developed. ART showed good linearity with regression coefficient (r<SUP>2</SUP>) of 0.9993 over the range of 30-80&#956;g/ml at 260 nm wavelength and LUM showed linearity over the range of 4-12&#181;g/ml at 286.2 nm wave length with correlation coefficient (r<SUP>2</SUP> ) of 0.9999. The analytical method was validated for simultaneous estimation of ART and LUM both as drug solutions, in tablets and in NLCs and validation parameters are reported. Intercept value of the linear lines determined for ART and LUM were nearly zero. ART and LUM showed accuracy of 99.215 and 99.564 in terms of % recovery. The relative standard deviation (RSD at n=6) intra-day: Inter-day precision for ART and LUM were 0.944:1.124 and 0.890:1.009 respectively indicating the method is precise. LOD (&#181;g/ml) and LOQ (μg/ml) values for ART were 0.3606 and 1.0928 and for LUM were 0.1145 and 0.3470 respectively. The developed method was successfully applied in the estimation of ART and LUM in commercial tablet (Arte plus CD) containing both the drugs.

Keywords

Artemether, Lumefantrine, Derivative Spectroscopy, Simultaneous Estimation, Validation

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Kurian Mathew ¹, S. S. Sarkar ¹, A. R. Srinivas ¹, Moumita Dutta ¹, Minal x Minal Rohit ¹, Harish Seth ¹, Rajiv Kumaran ¹, Kshitij Pandya ¹, Ankush Kumar ¹, Jitendra Sharma ¹, Jalshri Desai ¹, Amul Patel ¹, Vishnu Patel ¹, Piyush Shukla ¹, S. Manthira Moorthi ¹, Aravind K. Singh ¹, Ashutosh Gupta ¹, Jaya Rathi ¹, P. Narayana Babu ¹, Saji A. Kuriakose ¹, D. R. M. Samudraiah ¹, A. S. Kiran Kumar ¹

Affiliations
1 Space Applications Centre, Indian Space Research Organisation, Ahmedabad 380 058, IN

Abstract

Methane Sensor for Mars (MSM), on-board Mars Orbiter Mission is a differential radiometer based on Fabry–Perot Etalon (FPE) filters which measures column density of methane in the Martian atmosphere. It is the first FPE sensor ever flown to space. Spectral, spatial and radiometric performances of the sensor were characterized thoroughly during the pre-launch calibration. Geophysical calibration of the sensor was carried out using the data acquired over Sahara desert during Earth Parking Orbit phase. Retrieval algorithm for MSM, which is based on the linearization of radiative transfer equations, gets simultaneous solutions for CH4 and CO2 concentrations in the Martian atmosphere.

Keywords

Differential radiometer, Fabry–Perot Etalon, geophysical calibration, methane sensor, retrieval algorithm.

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Arup Roy Chowdhury ¹, Arup Banerjee ¹, S. R. Joshi ¹, Moumita Dutta ¹, Ankush Kumar ¹, Satadru Bhattacharya ¹, Amitabh ¹, Sami Ur Rehman ¹, Sunil Bhati ¹, J. C. Karelia ¹, Amiya Biswas ¹, Anish R. Saxena ¹, Satish Sharma ¹, Sandip R. Somani ¹, H. V. Bhagat ¹, Jitendra Sharma ¹, D. N. Ghonia ¹, B. B. Bokarwadia ¹, Ajay Parasar ¹

Affiliations
1 Space Applications Centre, Indian Space Research Organisation, Ahmedabad 380 015, IN

Abstract

Imaging Infrared Spectrometer (IIRS) is an imaging hyperspectral instrument for mineralogy of the lunar surface (including the hydroxyl signature). IIRS operates in the 0.8–5 μm spectral range with about 250 contiguous bands. It has 80 m ground sampling distance and 20 km swath at nadir from 100 km orbit altitude. Optical design is based on fore-optics and Offner (convex multi-blazed grating)-type spectrometer. Focal plane array is HgCdTe (mercury–cadmium–telluride)- based actively cooled to 90 K, having 500 × 256 pixels format with 30 μm pixel size. Electronics comprises proximity, logic and control, power supply and cooler drive electronics. Mechanical system is realized to house various subsystems, namely optics, detector, electronics and thermal components meeting the structural, opto-mechanical thermal component and alignment requirements. Thermal system is designed such that the instrument is cooled and maintained at fixed temperature to reduce and control instrument background. Aluminum-based mirror, grating and housing are developed to maintain structural as well as opto-mechanical and thermal requirements. This article presents IIRS realization and spectroradoimetric performance.

Keywords

Hyperspectral Imaging, Infrared Spectrometer, Moon, Orbiter.

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Arup Roy Chowdhury ¹, Manish Saxena ¹, Ankush Kumar ¹, S. R. Joshi ¹, Amitabh ¹, Aditya Dagar ¹, Manish Mittal ¹, Shweta Kirkire ¹, Jalshri Desai ¹, Dhrupesh Shah ¹, J. C. Karelia ¹, Anand Kumar ¹, Kailash Jha ¹, Prasanta Das ¹, H. V. Bhagat ¹, Jitendra Sharma ¹, D. N. Ghonia ¹, Meghal Desai ¹, Gaurav Bansal ¹, Ashutosh Gupta ¹

Affiliations
1 Space Applications Centre, Indian Space Research Organisation, Ahmedabad 380 015, IN

Abstract

Orbiter High Resolution Camera (OHRC) onboard Chandrayaan-2 Orbiter-craft, is a very high spatial resolution camera operating in visible panchromatic band. OHRC’s primary goal is to image the landingsite region prior to landing for characterization and finding hazard-free zones. Post landing operation of the OHRC will be for scientific studies of small-scale features on the lunar surface. OHRC makes use of the time delay integration detector to have good signal-tonoise ratio under low illumination condition and less integration time due to very high spatial resolution. Ground sampling distance (GSD) and swath of OHRC (in nadir view) are 0.25 m and 3 km respectively, from 100 km altitude. GSD is better than 0.32 m in oblique view (25° pitch angle) during landing site imaging from 100 km altitude in two stereo views in consecutive orbits. This article includes the details of the configuration, sub-systems, imaging modes, and optical, spectral and radiometric characterization performance.

Keywords

Ground Sampling Distance, Orbiter High Resolution Camera, Relative Spectral Response, Square Wave Response, Time Delay Integration.

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Arup Roy Chowdhury ¹, Vishnukumar D. Patel ¹, S. R. Joshi ¹, A. S. Arya ¹, Ankush Kumar ¹, Sukamal Paul ¹, Dhrupesh Shah ¹, Pradeep Soni ¹, J. C. Karelia ¹, Minal Sampat ¹, Satish Sharma ¹, Sandip Somani ¹, H. V. Bhagat ¹, Jitendra Sharma ¹, Amitabh ¹, K. Suresh ¹, R. P. Rajasekhar ¹, B. B. Bokarwadia ¹, Mukesh Kumar ¹, D. N. Ghonia ¹

Affiliations
1 Space Applications Centre, Indian Space Research Organisation, Ahmedabad 380 015, IN

Abstract

The paper presents the design and development of Terrain Mapping Camera-2 (TMC-2) for Chandrayaan- 2 including science objectives; system and sub-system configuration along with the realized performance of the camera; payload characterization; aspects related to data products, etc. TMC-2, onboard Chandrayaan-2 orbiter-craft is a follow-on of the Terrain Mapping Camera (TMC) onboard Chandrayaan- 1. It operates in visible panchromatic band. It comprises three identical electro-optical chains aligned for three views (–25, 0 and +25 degree) along track direction for generation of stereo images. It provides data with 5 m horizontal ground sampling distance to generate digital elevation model. TMC-2 based on the new configuration and sub-system designs has reduction in mass and power by more than 40% compared to TMC, without compromising the performance.

Keywords

Digital Elevation Model, Light Transfer Characteristics, Relative Spectral Response, Signal-to-noise Ratio, Stereo Imaging, Square Wave Response, Terrain Mapping Camera-2.

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A. S. Arya ¹, Joyita Thapa ², Abhik Kundu ², Rwiti Basu ², Amitabh ¹, Ankush Kumar ¹, Arup Roychowdhury ¹

Affiliations
1 Space Applications Centre, Jodhpur Tekra, Ambawadi Vistar, Ahmedabad 380 015, India, IN
2 Department of Geology, Asutosh College, 92, S.P. Mukherjee Road, Kolkata 700 026, India, IN

Abstract

The high-resolution panchromatic stereo camera Terrain Mapping Camera-2 (TMC-2) on-board the Indian Chandrayaan-2 mission sends images of the lunar surface at 5m resolution with a low to high sun-angle from an altitude of 100km. These images help identify subtle topographic variations and enable mapping of low-elevation landforms, one of which is a prominent ~220km long wrinkle ridge called the Dorsa Geikie (DG) lying within Mare Fecunditatis. The favourable resolutionof TMC-2 images and the digital elevation models provide opportunities for a detailed structural study of the DG and to reveal crustal shortening, cumulative contractional strain andpalaeostress regime responsible for thrust faulting for the first time.The time of deformation and formation of dorsa is also estimated for a holistic spatio-temporal understanding of deformation. This study presents initial analysis of the data received from TMC-2, and the accuracy of the results are likely to improve as the ingredients get amended and evolved in future

Keywords

Displacement-Length Scaling, Lunar Contraction, Mare Fecunditatis, Stress/Strain Evaluation, Wrinkle Ridges.

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Prakash Chauhan ¹, Mamta Chauhan ¹, Prabhakar A. Verma ¹, Supriya Sharma ¹, Satadru Bhattacharya ², Aditya Kumar Dagar ³, Amitabh ³, Abhishek N. Patil ³, Ajay Kumar Parashar ³, Ankush Kumar ³, Nilesh Desai ³, Ritu Karidhal ⁴, A. S. Kiran Kumar ⁵

Affiliations
1 Indian Institute of Remote Sensing, Indian Space Research Organization, Dehradun 248 001, IN
2 Space Applications Centre, Indian Space Research Organisation (ISRO), Ahmedabad 380 015, IN
3 Space Applications Centre, Indian Space Research Organisation (ISRO), Ahmedabad 380 015, India, IN
4 U.R. Rao Satellite Centre, ISRO, Bengaluru 560 017, India, IN
5 Indian Space Research Organisation Head Quarters, Bengaluru 560 094, India, IN

Abstract

Imaging Infrared Spectrometer (IIRS) on-board Chandrayaan-2 is designed to measure lunar reflected and emitted solar radiation in 0.8–5.0 μmm spectral range. Its high spatial resolution (~80 m) and extended spectral range is most suitable to completely characterize lunar hydration (2.8–3.5 μmm region) attributed to the presence of OH and/or H₂O. Here we present initial results from IIRS reflectance data analysed to unambiguously detect and quantify lunar 3 μmm absorption feature. After pre-processing and data-reduction, a physics based thermal correction analysis of IIRS reflectance spectra has been done using co-located temperature measurements. Hydration absorption was observed at all latitudes and surface types with varying degrees for all pixels in the study area and its absorption depth shows distinct variability associated with mineralogy, surface temperature and latitude.

Keywords

Imaging Infrared Spectrometer, Lunar Hydration, Moon, Reflectance Data, Thermal Correction.

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