Wahyudin Syam - Wasy Research

Brief discussions on uncertainty contributors of GNSS-based positioning (Part 3)

Pseudorange is the distance between a global navigation satellite system (GNSS) satellite and a receiver when the offset of the receiver clock (with respect to GNSS timeline) is not yet corrected.

GNSS

Brief discussions on uncertainty contributors of GNSS-based positioning (Part 2)

In this post, we will start from the highest view of how we can estimate a position from at least four GNSS satellite ranging signals.

GNSS

Brief discussions on uncertainty contributors of GNSS-based positioning (Part 1)

In this blog series, we will discuss about uncertainty contributors on GNSS positioning and open a way to estimate the uncertainty for reliable positioning.

GNSS

TUTORIAL: Interacting with Movella XSense IMU sensor in C++

Inertial measurement unit (IMU) sensor is important for global navigation satellite system (GNSS) based positioning, velocity and timing (PNT) solutions.

GNSS

Real-time decoding of NAV messages of Septentrio receiver in C programming language

Septentrio receiver is one of the most used global navigation satellite systems (GNSS) receivers, including u-blox and Novatel GNSS receivers.

GNSS

Reading raw binary IQ data in C/C++ with malloc() and pointer

Digital signal processing (DSP) of radio frequency (RF) data very often deals with read from and write to a binary file with IQ format.

Research

Classic philosophies that have been forgotten: Important factors for research and development

In this post, we will discuss the forgotten classic philosophies (values) that are instrumental for performing high quality research, development and innovation activities.

Metrology

Productive metrology: Evaluating the cost of part inspections

In this third post, we will discuss how the measurement cost affects the total production cost as well as how to correctly calculate the measurement cost to support a decision making for machine selection so that we can lower the total production cost.

Metrology

Productive metrology: The relation between uncertainty and economic benefit

In this second post about productive metrology, we will discuss how a measurement uncertainty can affect the economic benefit of metrology.

Metrology

Productive metrology: The role of metrology to transform data into know-how or wisdom

Metrology has been commonly seen as “cost-centre”. In this first post in the topic of “productive metrology” that is metrology as “profit-centre”, we will start by discussing the philosophical goal of metrology to gain know-how or wisdom.

GNSS

The importance of GNSS satellite clock-bias and orbit correction

The position of a receiver calculated from global navigation satellite system (GNSS) signals is significantly affected by the accuracy of the satellite clock-bias and orbit transmitted by GNSS satellites.

Applied programming

TUTORIAL: MATLAB software inter-connection and cooperation with PYTHON software using pyenv()

In a complex software application, most of the time, the application is written with several programming languages. These programming languages are inter-connected and cooperate together (compatible) to deliver the overall software functionalities.

Metrology

Error compensation for coordinate measuring instrument: Error separation and self-calibration

Rehearsal method is a method to separate combined or coupled errors into separated individual error elements. By separating the combined errors into individual errors, the error quantification of an instrument can be performed without a calibrated artefact and/or calibration instrument.

Metrology

Error compensation for coordinate measuring instrument: The mathematical model of 3-axis coordinate measuring machine (CMM)

The mathematical model of a measuring instrument is important for building the error compensation system for the instrument.

Metrology

Error compensation for coordinate measuring instrument: Steps and calibration instruments

For the implementation of error compensation on measuring instruments or machine tools, there are steps to follow, that are the reconstruction of an error map (via mathematical modelling via analytical or empirical methods) and the calibration process to quantify and characterise the error map.

Metrology

Error compensation for coordinate measuring instrument: introduction and types

Error compensation is an important process to produce an accurate measuring instrument. Any measuring instruments, although inherently constituted by accurate and precise components, always have some degree of error.

Research

Disruptive innovation to create growth: A research perspective

Economic growth is one of the main targets of a nation to reach prosperity. It is well known that developed nations leverage knowledge-based economic created from advanced research and high-value products or services.

Metrology

X-Ray computerised tomography (X-ray CT) for industrial part measurement: History, working principle, measurement procedure, applications and characteristics

X-Ray computerised tomography (X-ray CT) has the ability to non-destructively measure internal features of a part that is made of different materials including metals and non-metals.

GNSS

Correlator outputs for clean and spoofed GPS L1 C/A signals

The pseudorange and navigation data determination from global navigation satellite system (GNSS) signals are calculated from the correlator outputs at the tracking stage of the GNSS signal processing.

GNSS

Public datasets for spoofing and evil waveform (EWF) signals

Spoofing attacks on GNSS signals become more serious than ever due to the advancement of spoofing algorithms and computational capabilities and processing. These spoofing attacks transmit a counterfeit signal that leads to a wrong positioning, timing and navigation (PNT) solutions.

Research

Reverse step: building research and knowledge from data or observation study

Research is an iterative process and can be performed in either forward or reverse steps. Different fields of research require different research steps that best suit the specific situation of each field.

Metrology

Mathematical geometrical fitting: Direct least-square fitting of circle geometry (with tutorial and code)

Circle is a non-linear geometry that has a non-linear mathematical model. In this post, a closed-form and deterministic method to fit a circle from points (e.g., obtained from a measurement) by using direct least-square (DLS) estimation method is presented.

Metrology

Mathematical geometrical fitting: Automatic measurement algorithm case studies

In this post, practical case studies of algorithm implementations for automatic geometrical perpendicularity and cutting tool measurements are presented.

Metrology

Mathematical geometrical fitting: Data filtering of measurement points

Data filtering is a process to reduce noises or supress certain components or information contained in measurement data by using a specific kernel (filter).

Metrology

Mathematical geometrical fitting: Initial solution problems

Any iterative optimisation algorithms, used to optimise non-linear and multi-modal objective functions, always require an initial solution estimation.