Dinesh Sathyamoorthy

Science and Technology Research Institute for Defence | STRIDE

This paper aims to assess the impact of Global Navigation Satellite System (GNSS) spoofing on the performance of a Garmin GPSMAP 66sr dual-frequency GNSS receiver. The evaluation is conducted through field assessments under three conditions: 1) single-frequency GPS L1 coarse acquisition (C/A) only, 2) single-frequency GPS L1 C/A and Galileo E1 open...

This study is aimed at evaluating the vulnerabilities of unmanned aerial vehicles (UAVs) to Global Positioning System (GPS) jamming and spoofing. It is conducted for two commercial UAVs: Osman X28 (UAV A) and CSJ S167 (UAV B). The results obtained demonstrate that UAVs are susceptible to GPS jamming and spoofing even at relatively low power levels...

In this study, Global Positioning System (GPS) simulation is used to evaluate the effectiveness of receiver autonomous integrity monitoring (RAIM) in GPS receivers. The study is conducted on two GPS receivers: 1) A receiver that supports RAIM-a GM1-86UB receiver that uses a u-blox 6 GPS chipset; 2) A receiver that does not support RAIM-a Garmin GPS...

With the growth of the population, the development of industrial, agricultural and so on, the amount of gas demand has been increasing steadily. Supplying the required gas energy often involves the construction of new power plants. The construction of power plants has social, economic, political and environmental consequences. Given the impact of p...

This study is aimed at evaluating Global Navigation Satellite System (GNSS) Space Service Volume (SSV) performance in terms of number of visible GNSS satellites. This study focuses on the two GNSS systems that currently have full operating capability (FOC), namely Global Positioning System (GPS) and Globalnaya Navigatsionnaya Sputnikovaya Sistema (...

The study of landform can be used to predict specific solid rock and moisture conditions that exist in that landform. Landforms are of significance in engineering because they influence the quality and type of grading, pre-determine the drainage requirements, and the soil or rock conditions. They have added significance because there are an infinit...

The study of groundwater resources in relation to topography is important. Clearly, in different topography, depth of the water level is different. Therefore, the aim of this study is the determination of the relationship between landform classes with compound topographic index ( CTI ) and depth of the water for the Maharlou-Bakhtegan watershed, Fa...

In arid and semi-arid regions, distributions of irregular spatial and temporal rainfall cause vegetation to be damaged by droughts, which leads to political problems between different countries. In these areas, one of the ways to prevent land degradation is the use of flooding for artificial recharge of groundwater aquifers. Determination of suitab...

This study is aimed at evaluating adjacent radio frequency band power levels that can be tolerated by the Global Positioning System (GPS) L1 coarse acquisition (C/A) signal and the extent to which such power levels impact GPS performance. The study is conducted using GPS simulation, which allows for the tests to be held with various repeatable cond...

Presents GRSS chapter events from Malaysia.

This study is aimed at evaluating the effect of Global Positioning System (GPS) antenna orientation for three Garmin GPS receivers that use built-in quad helix antennas; GPSmap 60CSx, GPSmap 62Cs and Oregon 550. The study is conducted using GPS simulation, which allows for the tests to be held with various repeatable conditions, as defined by the a...

The selection of competent tenderers in high-value projects and procurements is very critical, as it determines the risks and outcomes of the projects. In some government procurement systems, millions of dollars are at stakes. Unfortunately, a significant number of high-value projects and procurements have failed to achieve the intended goals and s...

In this study, the fuzzy analytic hierarchy process (AHP) is used to study the relationship between drinking water quality based on content of inorganic components and landform classes in the south of Firozabad, west of Fars province, Iran. For determination of drinking water quality based on content of inorganic components, parameters of calcium (...

In this study, fuzzy analytic hierarchy process (AHP) is used to study the relationship between drinking water quality and landform classes in south of Firozabad, east of Fars province, Iran. For determination of drinking water quality, parameters of calcium (Ca), chlorine (Cl), magnesium (Mg), thorium (TH), sodium (Na), electrical conductivity (EC...

The aim of this study is to cluster landforms in the west of the Fars province, Iran using self-organizing maps (SOM). In SOM, according to qualitative data, the clustering tendencies of landforms were investigated using six morphometric parameters, which were slope, profile, plan, elevation, curvature and aspect. First, topographic position index...

Soil genesis is highly dependent on landforms as they control the erosional processes and the soil physical and chemical properties. The relationship between landform classification and electrical conductivity (EC) of soil and water in the northern part of Meharloo watershed, Fars province, Iran, was investigated using a combination of a geographic...

This study aims to investigate the relationship between landform classification and vegetation in the southwest of Fars province, Iran. First, topographic position index (TPI) is used to perform landform classification using a Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) with resolution of 30 m. The classification has ten c...

The aim of this study is to cluster landforms in the west of the Fars province, Iran using selforganizing maps (SOM). According to qualitative data, the clustering tendencies of landforms are investigated using six morphometric parameters, which are slope, profile, plan, elevation, curvature and aspect. First, topographic position index (TPI) is...

In this research, the relationship between classes of landform, and electrical conductivity (EC) of soil and water in the Shiraz Plain, Fars province Iran was investigated using a combination of geographical information system (GIS) and fuzzy model. The results of the fuzzy method for water EC showed that 36.6 % of the land to be moderately land su...

This study is aimed at providing a comparative analysis of multiple linear regression (MLR), and two artificial neural network (ANN) models, multi-layer perceptron (MLP) and radial basis function (RBF), for predicting evapotranspiration using available weather data in the southwest of the Fars province, Iran. Evapotranspiration was calculated using...

The North Fars watershed is one of the major sources of irrigation and drinking water supplies for the Fars province in Iran. The major sources of water for this watershed are rain and snow. Morphometric analysis of the study area, consisting of 14 subwatersheds (W1 to W14), was carried out. It is found that that the entire watershed has uniform li...

In this study, the Mazandran River watershed is selected for detailed morphometric analysis. Morphometric analysis for parameters of stream number (Nu), stream order (U), cumulative length of streams (L), bifurcation ratio (Rb), watershed relief (Bb), drainage density (Dd), stream frequency (Fs), form factor (Rf), circularity ratio (Rc) and elongat...

This study is aimed at evaluating the trade-off between Global Positioning System (GPS) accuracy and power saving from reduction of number of channels. The study is conducted for number of GPS receiver channels of 4 to 12 for two scenarios: (1) normal scenario with full range of available GPS satellites and (2) obstruction scenario with GPS satelli...

In this study, Global Positioning System (GPS) simulation is employed to evaluate the accuracy of GPS speed measurements. The two methods of GPS speed measurement, trackpoints and Doppler shift, are compared for two conditions of tests: 1) Normal scenario with the full range of available GPS satellites; 2) Obstruction scenario with only six GPS sat...

The aim of this paper is to analyze topographic and aspect effects on vegetation indices in the Darab mountain, Iran. Three commonly used vegetation indices, normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) and difference vegetation index (DVI), were computed from Landsat 8 ETM+ vegetation bands. Based on the results o...

The use of unmanned aerial vehicles (UAVs) has increased exponentially over the last decade for a broad range of applications. The recent commercial availability of a new generation of small UAVs has emphasised the growing threat posed by these machines. This paper is aimed at reviewing the security threats posed by UAVs in areas such as terrorist...

This study is aimed at evaluating the trade-off between Global Positioning System (GPS) accuracy and power saving from reduction of number of channels. The study is conducted for number of GPS receiver channels of 4 to 12 for two scenarios: 1) Normal scenario with full range of available GPS satellites; 2) Obstruction scenario with GPS satellite el...

Multi-criteria decision making (MCDM) is an area that is often discussed in operations research (OR). It is able to handle problems involving multiple criteria, and produce meaningful and quality decision making, especially in selecting the best alternative. This paper is aimed at reviewing the applications of MCDM for technical evaluation of tende...

This study is aimed at evaluating the effect of Global Positioning System (GPS) satellite clock error using GPS simulation. Two conditions of tests are used; Case 1: All the GPS satellites have clock errors within the normal range of 0 to 7 ns, corresponding to pseudorange error range of 0 to 2.1 m; Case 2: One GPS satellite suffers from critical f...

This study is aimed at performing landform classification using multiscale analysis, which is implemented on Shuttle Radar Topography Mission (SRTM) digital elevation models (DEMs) with spatial resolution of 90 m using quadratic parameterization and the lifting scheme. Multiscale DEMs with scales of 5 to 55 cells are prepared using the two methods....

Wireless spy devices (WSDs) are surveillance equipment, such as listening bugs or cameras, hidden in objects or covertly placed in rooms. Surveillance using WSDs is one of the main methods of recording conversations for both intelligence gathering as well as criminal charges. However, WSDs have also been abused for nefarious purposes, such as indus...

In this study, we investigate the use of morphometric parameters and fuzzy membership functions to perform landform classification for different case areas of Zagros Mountains from digital elevation models (DEMs). First, multiscale DEMs with scales of 5 to 45 cells are generated using the lifting scheme. The maximum curvature for the scale of five...

The derivation of spatial significance is an important aspect of geospatial analysis and hence, various methods have been proposed to compute the spatial significance of entities based on spatial distances with other entities within the cluster. This paper is aimed at studying the spatial significance of mountain objects extracted from multiscale d...

The aim of this study is to classify alluvial fans formed by high-gradient braided streams and torrents that discharge into the Oshtorankook altitudes in the Lorestan province, Iran. The morphology of the fans and their watershed is quantitatively described through estimated morphometric parameters. For relationships between geomorphological featur...

In this study, Global Positioning System (GPS) simulation is employed to study the effect of five commonly used materials (aluminium, glass, wood, polyvinyl chloride (PVC) and ceramic) on multipath propagation of GPS signals. Based on the results of this study, it is found that multipath signals from panels made of the materials cause increase in p...

There is a steady growth in the entrenchment of Global Navigation Satellite Systems (GNSS) in current and upcoming markets, having penetrated various consumer products, such as cell phones, personal navigation devices (PNDs), cameras and assimilation with radio-frequency identification (RFID) tags, for various applications, including navigation, su...

Morphometry research used geography information system (GIS) to explore alluvial fan morphology for determination of fans location and fast and accurate analysis. The aim of this study is to classify alluvial fans formed by high-gradient braided streams and torrents that discharge into the Oshtorankook altitudes in the Lorestan province, Iran. The...

The derivation of spatial significance is an important aspect of geospatial analysis and hence, various methods have been proposed to compute the spatial significance of entities based on spatial distances with other entities within the cluster. This paper is aimed at studying the spatial significance of mountain objects extracted from multiscale d...

The successful of GPS observations are dependent on several factors between satellite vehicles and GPS receivers, where low GPS power levels have led to the threat of radio frequency interference (RFI) on the GPS signals. This study was conducted to evaluate the effect of RFI on the precision of positions of single and dual frequency receivers thro...

While a number of methods have been proposed to study the effect of scale on intrinsic spatial attributes of terrains, from the aspect of simplicity and performance, local variance LV is more widely used for geospatial analysis. This paper is aimed at providing a comparative analysis of cell- and object-based LV for physiographic features extracted...

This study is aimed at addressing a mistake made in the authors' previous paper on Global Positioning System (GPS) static multipath simulation (Dinesh et al., 2013), whereby it was indicated that GPS performance is repeatable for every GPS satellite orbital pass of approximately 11 h, 58 min. GPS satellites only return to the original positions wit...

This paper is aimed at employing grey level co-occurrence matrix (GLCM) to analyse the surface textures of physiographic features extracted from multiscale digital elevation models (DEMs). Four GLCM parameters, energy, contrast, autocorrelation and entropy, are computed for horizontal (0°), vertical (90°) and diagonal (45 and 135°) cell pair orient...

Global Navigation Satellite Systems (GNSS) are being increasingly used for a variety of marine and aircraft navigation, vehicle theft monitoring, cargo tracking, and critical time synchronisation for utility, telecommunications, banking and computer industries. At present, there are two types of GNSS signals; military GNSS signals (L1 P(Y) and L2 P...

the Malaysian coastal environment. Hence, this research objective is aimed at designing a coastal environment training grounds in Lumut (Perak), Pulau Indah (Selangor) and Port Dickson (Negeri Sembilan) were selected. The captured images of the study areas were the regions of interest for the pattern templates were picked based on the variation of...

The effect of radio frequency interference (RFI) on Global Positioning System (GPS) signals needs to be investigated because of the increasing demand for accuracy and precision in positioning, navigation, and timing (PNT) applications. In order to investigate the effect of RFI on the high precision GPS applications (e.g., surveying works), this stu...

This paper presents the development of a prototype unmanned surface vessel (USV) platform for water quality measurement. Based on several hull concept designs made using Solidworks, the catamaran design was determined as the most suitable for the platform due to its stability and manoeuvrability performance. The platform's design was optimised usin...

In this study, Global Positioning Satellie (GPS) simulation is employed to study the effect of multipath on two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSmap 60CS (reference GPS receiver). Both GPS receivers employ the GPS L1 coarse acquisition (C/A) signal. Based on the results of this study, it is found th...

While a number of camouflage patterns have been designed, none of them are suitable for the Malaysian coastal environment. Hence, this research objective is aimed at designing a camouflage pattern for Royal Malaysian Navy (RMN) coastal patrol boats. Representative coastal environment training grounds in Lumut (Perak), Pulau Indah (Selangor) and Por...

This study is aimed at evaluating Global Positioning System (GPS) performance during simplistic GPS spoofing attacks, whereby spoofing is conducted using a standalone GPS simulator, which at present poses the greatest near-term threat. The study is conducted on two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSm...

In this study, Global positioning system (GPS) simulation is employed to study the effect of radio frequency interference (RFI) on the accuracy of two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSmap 60CS (reference GPS receiver). Both GPS receivers employ the GPS L1 coarse acquisition (C/A) signal. It was foun...

In this study, Global positioning system (GPS) simulation is employed to study the effect of radio frequency interference (RFI) on the accuracy of two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSmap 60CS (reference GPS receiver). Both GPS receivers employ the GPS L1 coarse acquisition (C/A) signal. It was fou...

Given the various incidents of intentional and unintentional jamming of Global Navigation Satellite System (GNSS) signals, the Science & Technology Research Institute for Defence (STRIDE) conducted a series of tests to study the effect of radio frequency interference (RFI) on Global Positioning System (GPS) signals. The initial tests were conducted...

Disruptive patterns are used on military uniforms as camouflage to blend in with the surrounding. Recent camouflage designs are based on small fractal-like patterns emulating natural surroundings. Present evaluations of camouflage patterns mostly rely on human visual assessment, which can be subject to bias. To this end, this paper proposes a photo...

In this paper, a modification of the algorithm proposed by Ahmad Fadzil et al. (2011) for surface roughness computation from digital elevation models (DEMs) via multiscale analysis is presented. The new algorithm takes into account that the three predominant physiographic features of terrains (mountains, basins and piedmont slopes) have distinct cu...

While a number of studies have been conducted on classification on various landforms extracted from multiscale digital elevation models (DEMs), not much attention has been provided on the effect of multiscaling on elevation variances. To this end, in this paper, the statistical analysis of elevation variances of cells of physiographic features extr...

In this study, Global Positioning System (GPS) simulation is used to evaluate the effect of varying GPS signal power levels on the accuracy of two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSmap 60CS (reference GPS receiver). Both receivers employ the GPS L1 coarse acquisition (C/A) signal. With decreasing GPS...

In a previous study, the determination of suitable RF detectors for detection of wireless spy devices was conducted via the measurement of two key parameters; operating bandwidth and power level threshold. However, this study was limited to RF detectors with maximum operating frequency of up to 3 GHz (based on provided speci cations). This paper is...

On 28 June 2011, the Instrumentation & Electronics Technology Division (BTIE) conducted a test to compare the transmitted signals of two mobile phone jammers (MPJs) a portable MPJ (MPJ34) and a high powered MPJ (MPJ2000). Both MPJs are designed to operate in the bandwidths of Code Division Multiple Access (CDMA), Global System for Mobile Communicat...

Recent efforts to control the spread of epidemic infectious diseases, such as the 2003 severe acute respiratory syndrome (SARS) outbreak, the 2006 avian in uenza outbreak and 2009 in uenza A(H1N1) pandemic, have prompted health of cials to develop rapid screening processes to detect febrile patients. The ideal device for fever screening should be s...

Sunspots, which are a natural phenomenon that occurs due to magnetic activity on the sun's surface, can be counted using smoothed sunspot number (SSN). Flares and prominences of SSNs radiate free ions in the ionosphere. This has signi cant effect on the stability of the ionosphere, resulting in the frequencies that can be used for high frequency (H...

In this paper, an algorithm to compute surface roughness of digital elevation model (DEM) terrains via multiscale analysis is proposed. The algorithm employs the lifting scheme to generate multiscale DEMs. At each scale, the areas of pixels that are modified are computed. Granulometric analysis is employed to compute the average area of curvature r...

The study of the geometric properties of simulated droughts and floods of water bodies is important in understanding the dynamic behavior of water bodies.Hence, recent studies have been conducted to characterize key geometric properties of simulated droughts and floods of water bodies, including convexity, influence zones, skeletons and regions of...

In December 2010 to February 2011, the Instrumentation & Electronics Technology Division (BTIE) conducted a series of tests to measure the operating bandwidth and power level threshold of two RF detectors; HomeSafe (model 790) and Ghost (model CT-AS0039). It was determined that the Ghost RF detector's Channel A has the largest operating bandwidth (...

This paper is aimed at conducting a critical assessment of two key defence R&D elds that are important in supporting the development of the national defence industry, in particular in supporting the achievement of the objectives of the Fourth Dimension Malaysian Armed Forces (4D MAF) capability plan in terms of operational awareness and mission cap...

Previous tests conducted by the Instrumentation & Electronics Technology Division (BTIE), Science & Technology Research Institute for Defence (STRIDE), were aimed at evaluating the minimum interference signal power level required to jam the Global Positioning System (GPS) L1 coarse acquisition (C/A) signal. However, the tests were only performed us...

In general, analysis of mountains is often performed at singular scales of measurement. However, analysis of a location at multiple scales allows for a greater amount of information to be extracted from a DEM about the spatial characteristics of a feature. Hence, the variation in the spatial resolution over which mountains are defined has been used...

In order to study the effect of radio frequency interference (RFI) on the global positioning system (GPS) LI coarse acquisition (C/A) signal, the Instrumentation & Electronics Technology Division (BTIE), Science & Technology Research Institute for Defence (STRIDE), conducted a series of tests specifically aimed at evaluating the minimum interferenc...

Abstract Surface roughness is a useful tool for terrain analysis as it reflects numerous geophysical parameters, such as landform characteristics, distribution of crenulations and degree of erosivity. Hence, in the past few decades, the quantitative computation of surface roughness ofterrains for the purposes of numerical surface study has received...

Global Navigation Satellite Systems (GNSS) are being increasingly used for a variety of important applications, including public safety services (police, fire, rescue and ambulance), marine and aircraft navigation, vehicle theft monitoring, cargo tracking, and critical time synchronization for utility, telecommunications, banking and computer indus...

During flooding processes, randomly situated water bodies of varying sizes and shapes in a floodplain tend to self-organize. At high degrees of flooding intensity, water bodies contact together to form influence zones, which indicate the self-organized criticality of the flooding of water bodies. The characterization of water bodies and their influ...

The quantitative computation of surface roughness has received increasing attention due to its importance in numerical surface study. A number of algorithms have been employed to compute surface roughness. These algorithms, which operate at singular scales of measurement, provide scale-dependant roughness parameters. In this paper, the computation...

In this study, a mathematical morphological based algorithm to extract watersheds from Digital Elevation Models (DEMs) is proposed. First, spurious peaks and pits in the DEM are removed by generating a smoothened DEM using morphological smoothening by reconstruction. The pits of the smoothed DEM are extracted by implementing ultimate erosion on the...

The characterization of three important hydrological features, drainage networks, ridge networks and watersheds, is essential in the study of the geomorphological organization of a given terrain. In this study, mathematical thinning based algorithms to extract these three hydrological features from Digital Elevation Models (DEMs) are developed. Fir...

In this study, a procedure to compute the surface roughness of individual mountain objects extracted from Digital Elevation Models (DEMs) is proposed. First, mathematical morphology is employed to extract the mountains of the DEM. The lifting scheme is employed to perform the generation of multiscale DEMs. The mask of pixels modified in each mounta...

Morphometry (also known as geomorphometry) is the science of measuring and depicting parameters or attributes necessary to describe the precise nature and configuration of the earth topography, its geographic relationships to the land mass and the characteristics of geomorphologic processes. In this paper, the computation of the basic morphometric...

In this paper, the effect of smoothing on the extraction of drainage networks from simulated digital elevation models (DEMs) is studied. First, morphological smoothing is implemented on a simulated DEM using square kernels of increasing size to generate smoothed DEMs. The drainage networks extracted from the generated smoothed DEMs are then charact...