Classification of North Africa for Use as an Extended Pseudo Invariant Calibration Sites (Epics) for Radiometric Calibration and Stability Monitoring of Optical Satellite Sensors

An increasing number of Earth-observing satellite sensors are being launched to meet the insatiable demand for timely and accurate data to help the understanding of the Earth’s complex systems and to monitor significant changes to them. The quality of data recorded by these sensors is a primary concern, as it critically depends on accurate radiometric calibration for each sensor. Pseudo Invariant Calibration Sites (PICS) have been extensively used for radiometric calibration and temporal stability monitoring of optical satellite sensors. Due to limited knowledge about the radiometric stability of North Africa, only a limited number of sites in the region are used for this purpose. This work presents an automated approach to classify North Africa for its potential use as an extended PICS (EPICS) covering vast portions of the continent. An unsupervised classification algorithm identified 19 “clusters” representing distinct land surface types; three clusters were identified with spatial uncertainties within approximately 5% in the shorter wavelength bands and 3% in the longer wavelength bands. A key advantage of the cluster approach is that large numbers of pixels are aggregated into contiguous homogeneous regions sufficiently distributed across the continent to allow multiple imaging opportunities per day, as opposed to imaging a typical PICS once during the sensor’s revisit period. In addition, this work proposes a technique to generate a representative hyperspectral profile for these clusters, as the hyperspectral profile of these identified clusters are mandatory in order to utilize them for performing cross-calibration of optical satellite sensors. The technique was used to generate the profile for the cluster containing the largest number of aggregated pixels. The resulting profile was found to have temporal uncertainties within 5% across all the spectral regions. Overall, this technique shows great potential for generation of representative hyperspectral profiles for any North African cluster, which could allow the use of the entire North Africa Saharan region as an extended PICS (EPICS) dataset for sensor cross-calibration. Furthermore, this work investigates the performance of extended pseudo-invariant calibration sites (EPICS) in cross-calibration for one of Shrestha’s clusters, Cluster 13, by comparing its results to those obtained from a traditional PICS-based cross-calibration. The use of EPICS clusters can significantly increase the number of cross-calibration opportunities within a much shorter time period. The cross-calibration gain ratio estimated using a cluster-based approach had a similar accuracy to the cross-calibration gain derived from region of interest (ROI)-based approaches. The cluster-based cross-calibration gain ratio is consistent within approximately 2% of the ROI-based cross-calibration gain ratio for all bands except for the coastal and shortwave-infrared (SWIR) 2 bands. These results show that image data from any region within Cluster 13 can be used for sensor crosscalibration. Eventually, North Africa can be used a continental scale PICS

Bidirectional Distribution Reflection Function of Algodones Dunes

The primary objective of this project was to develop the Algodones Dunes as a pseudo-invariant calibration site (PICS) suitable for absolute calibration of satellite sensors based on a surface reflectance model. Two approaches were taken during this research: a field campaign and laboratory measurements. The first approach, the field campaign, was accomplished with a trip to the Algodones Dunes from the 8th to the 13th of March, 2015. During the field campaign, several test points from spatially different regions of the Algodones Dunes were studied. Reflectance of the sand at each test point was observed from different view angles. The second approach, laboratory testing, involved bringing several sand samples from different regions of the Algodones Dunes back to SDSU for further analysis. The laboratory setup was built in the SDSU optics laboratory and included the use of a light source, digital power supply, and mechanical arm to study the spectral responses of the sand samples from the field. During the laboratory measurements, the reflectance of each of the sand sample, was observed from different view angles to replicate field measurement techniques. Through both approaches it was found that the reflectance of sand samples from the Algodones Dunes changes quadratically with respect to view zenith angle. To correlate field and laboratory measurements, two solar zenith angles were chosen for laboratory simulation, i.e. 45and 54.4. Since the solar zenith angle varies from 20to 60 over a year in the Algodones Dunes, angles within that range were chosen for the solar zenith angles used in the laboratory measurements. The spectral response of different sand samples were only observed under those two chosen solar zenith angles. Since different equipment was used in the laboratory than in the field, there was some degree of uncertainty due to each of the differing instruments which influenced the data. A Linear Mixed Model was therefore developed in order to incorporate the laboratory uncertainties and predict a more accurate model using the raw data acquired in the laboratory. The data modeled by the Linear Mixed Model approach for different BRDF runs of the same sample, and for different sand samples, were compared to determine whether the spectral response of sand samples from the Algodones Dunes is the same or not. Based on the data modeled by the Linear Mixed Model, it was found that the spectral responses of sand samples brought from the Algodones Dunes are the same. A simple BRDF model was then developed for those angles that are perpendicular to the principal plane of the solar illumination

Role of seed priming in improving seed germination and seedling growth of maize (Zea mays L.) under rain fed condition

Seed priming enhances early seed emergence and proper crop stand establishment which enables the crop to capture more soil moisture, nutrients, and solar radiation. An on-farm experiment was conducted in Okhaldhunga, Nepal to study the effect of six different priming treatments (50 millimoles common salt solution, 200 millimoles urea solution, 1 percent MOP solution, 2.5 times diluted urine, water, and control) on germination and growth of two maize varieties, Manakamana-3 and Nutan-IL60. The experiment was set up in factorial randomized complete block design with three replications. Various germination traits: germination percent, seedling vigour, germination index, mean germination time, and seedling growth traits: shoot length, root length, and dry root weight, were studied. Nitrogen-based (Urea and Urine) priming resulted the most desirable change for the studied traits. Nitrogen-based priming also had significant positive effect on stress tolerance related traits like root length and dry root weight

Digital Portable Weather Station Monitoring System Using Arduino Uno

The temperature,humidity,atmospheric pressure and altitude are the most important parameters of the environment.If those parameters are known,it will help to select the best crops for specific location which increases the productivity in agricultural field.This is very useful for countries like Nepal where the most of people in this country depends on agriculture.In this research,an Arduino based device is constructed which measures those parameters and record the data in real time.The DHT22 and BMP180 sensors are used for measurin those parameters whereas RTC and SD Card module is used to record the data in real time. Data can be displayed on LCD and serial monitor of computer or laptop.The data were collected at Tri-Chandra Multiple College,Ghantaghar and at Gaurighat,Chabahil with the help of Arduino based device.In this project, the digital portable weather station monitoring system has been designed and data from this device compared with the data obtained from HTC-2 standard device and error analysis has been done

Air Pollution Monitoring System Using Micro Controller Atmega 32A and MQ135 Gas Sensor at Chandragiri Municipality of Kathmandu City

Air is one of the essential elements of human’s surroundings. The earth’s atmosphere is full of air which contains gases such as Nitrogen, Oxygen, Carbon Monoxide and traces of some rare elements. But quality of the air has been degrading for some decades due to various activities conducted by the human beings that directly or indirectly affect the atmosphere leading to the air pollution. There are different techniques to measure air quality.However, with the evolution of time the expensive and less efficient analog devices have been replaced by more efficient and less expensive electronics device. In this research, MQ135 sensor is used to measure air quality of a particular location. I2C display is used to monitor the data. Indeed, with the increasing in number of vehicles, unplanned urbanization and rapid population growth, air pollution has considerably increased in the last decades in various areas of Kathmandu. Thus, this project ‘Air Pollution Monitoring System’ was focused on collection of the data specific location of Chandragiri municipality of Kathmandu city. In conclusion,analysis of the data is done with the help of origin software which shows that the Arduino device in this device works perfectly for measuring the air pollution. Air quality of the selected area is found to be less than 500 PPM which concludes that the air quality of this area is normal

Designing of the Wireless Digital Portable Temperature and Humidity Monitoring Device and Analyzing Data at Different Part of Kathmandu Valley

The atmosphere of planet plays a great role in numerous weather phenomena which affects our life directly. To understand these phenomena, it requires knowledge about the relation between temperature and humidity.The effects of temperature on humidity influence the potential for precipitation. It also directly influences the human health and well-being. Relative humidity and dew point are the two parameters that are used by the meteorologists for understanding the interaction between temperature and humidity. Therefore there is a necessary of a smart monitoring system which is fully automated, accurate and capable enough to monitor all the parameters with accuracy. Besides, it should be portable and less expensive. For this purpose, the digital portable wireless temperature and humidity monitoring device is designed. This project consists of HC-05 Bluetooth module, DHT-11, Arduino UNO, 16 X 2 LCD, and smartphone. The data are recorded at different part of Kathmandu Valley with this device wirelessly by using smartphone and analyze it with the help of Origin software.

Urban Land Governance: “Action Space”, Legitimacy of and Intervention Strategies for Urban Informal Settlements in Nepal

At the global level, the informal settlements are in a dichotomy of legal and illegal debates. This paper analyzes the issue of informal settlements from the legitimacy perspective. It reveals that, although the settlements are not in legal legitimacy, there is tendency of social legitimacy. The challenges of urban land governance are in how to minimize the gap between legal legitimacy and social legitimacy. Firstly, this paper explores on how the actions of government and non-government organizations contribute towards legitimacy. To achieve this aim, the analytical framework of “action space” is applied. Secondly, it focuses on identifying intervention strategies that narrow the gap between legal legitimacy and social legitimacy. We studied two cases of informal settlements: the rst is to explore the gap and the second is to explain the intervention strategies. The results show, that due to lack of “action space” of government actors towards legal legitimacy, the civil society actors created their own “action space” which ultimately triggered social legitimacy. In addition to civil society, the actions of local authorities are found to contribute towards social legitimacy as well. To narrow the gap, the identi ed intervention strategies are discussed within the scope of land policy, land tenure security and land development

3D Nonwoven Fabrics for Biomedical Applications

Fibrous materials are attractive for biomedical applications owing to their structural superiorities, which include large surface-area-to-volume ratio, high porosity, and pore interconnectivity in a controlled manner. Among the various methods of fiber fabrication, electrospinning has emerged as an attractive nanotechnology to produce ultrafine fibrous materials for myriad applications, including tissue scaffolding. In this technique, processing parameters, such as the solution properties, tip-to-collector distance, applied voltage, etc., can be tailored to obtain the fibers of the desired morphology and physicochemical properties. Ideal scaffolds should meet the basic requirements, such as three-dimensional (3D) architecture, proper mechanical properties and biodegradability, and the sufficient surface characteristics for cell adhesion and proliferation. However, most of the electrospun nanofiber-based scaffolds have densely packed two-dimensional (2D) array which hinders the cell infiltration and growth throughout the scaffolds, thereby limiting their applicability in tissue regeneration. To overcome this problem, several attempts have been made to develop a biomimetic three-dimensional, nanofibrous scaffold. This chapter deals with noble techniques including gas foaming (GF), charge repulsion-assisted fabrication, post-processing, liquid-assisted collection, collector modification, and porogen-assisted methods for the fabrication of 3D nanofibrous scaffold for biomedical applications

Variability for growth and yield traits in single cross hybrids of maize (Zea mays L.)

Saabunud / Received 29.09.2021 ; Aktsepteeritud / Accepted 18.11.2021 ; Avaldatud veebis / Published online 18.11.2021 ; Vastutav autor / Corresponding author: Jiban Shrestha [email protected] single-cross hybrids of maize were evaluated in a randomized complete block design with three replications to investigate genetic variability and correlation among growth and yield traits at Khumaltar, Lalitpur, Nepal from March 13 to September 05, 2021. The hybrids were grouped into four clusters using Euclidean Average Linkage method. The cluster analysis showed the presence of genetic variability in the evaluated hybrids. The maximum distance between cluster centroids (194.28) was found between cluster 2 and cluster 4, indicating genetic dissimilarity. Grain yield had the maximum values of phenotypic coefficient of variation (PCV) (35.02%), followed by ear height (17.82%) and plant height (12.22%). Similarly, grain yield had the maximum values of genotypic coefficient of variation (GCV) (26.24%) followed by the number of kernel rows/cob (8.77%) and days to 50% silking (8.72%). Days to 50% silking and days to 50% tasseling had the highest values of heritability (86%) followed by cob diameter (84%) and no. of kernel rows in cob (68%). The leaf area per plant had the maximum values of genetic advance (GA) (74.87 cm2), followed by plant height (27.80 cm) and days to 50% silking (9.66 days). Similarly, the maximum values of genetic advance as percent of the mean (GAM) was found for grain yield (40.50%) followed by days to 50% silking (16.70%) and days to 50% tasseling (16.17%). The hybrids namely KWM-91 × KWM-93 produced the maximum values of grain yield (9.99 t ha–1) followed by KWM-93 × KWM-91 (9.63 t ha–1) and KWM-92 × KWM-93 (9.40 t ha–1). Grain yield showed positive and significant phenotypic correlation with days to 50% silking (r = 0.41), days to 50% tasseling (r = 0.39), plant height (r = 0.37), cob diameter (r = 0.49) and the number of kernel rows in cob (r = 0.38). Therefore, utilization of present genetic variability along with indirect selection for traits having significant association with grain yield, high heritability and GAM could aid in the improvement of maize productivity

In vitro Cultivation of Newly Reported Wild Edible Mushroom Volvariella bomybycina from Nepal

Wild edible mushrooms are becoming endangered all over the world. Very few wild edible mushrooms are found in natural habitat. Volvariella bombycina is an edible and medicinal mushroom. The mushroom was collected in natural habitat growing on Populus tree. Mycelium of the mushroom was developed in PDA slant tubes by tissue culture method, incubated at 25°C for 1-2 weeks. Spawn was developed in wheat grains after incubation at 25°C for 2-3 weeks. Substrates were formulated for the development of fruiting bodies by combination of paddy straw, saw dust and rice husk. Fruiting bodies of V. bombycina was cultivated in these substrates after incubation at 28 ± 2°C for 2-4 weeks. The work describes the optimized process for in vitro culture of wild edible mushroom Volvariella bomybycina.Nepal Journal of Biotechnology. Dec. 2017 Vol. 5, No. 1: 27-3