Abstracts of previous student projects

2nd semester

3rd semester, 4th semester

2010 

GPS Snapshot Techniques: An Approach for photo tagging

By: Tudor Iacobescu Ioan, Oriol Badia Sole

Software-defined receivers are becoming a more and more attractive technology in the GPS field. The idea of minimizing hardware components and  hanging over the signal processing load to programmable devices which support modifiable software is very appealing.

The motivation of the present project is to study and develop GPS snapshot techniques. Serving this purpose, we focused on a single application, photograph geo-tagging for digital cameras.

This concept is approached by analyzing, implementing and comparing different acquisition techniques, followed by the implementation and testing of the coarse-time navigation algorithm.

Results verify that the achieved accuracy is good enough for such application.

2009

The Effects of Applying EGNOS

By: Ander Gorocica Zubia, Sandra Mendieta Yaben, Niels Kaare Rasmussen and Luben Lillianov Ivanchev

The ionosphere cause a significant error in accurate position computation. Eliminating its effect can reduce positional error to a metre level. The aim of this paper is to gain a better understanding of what the ionosphere is. This paper also looks at the European SBAS System, EGNOS, and how it is intended to correct ionospheric delay. This paper presents a software program that computes a position using EGNOS corrections and compares it to a position that does not use EGNOS correction. It also compares the two positions to the exact position that is known.

Assisted GPS System Design

By: Andrei Marinescu and Dragos Catalin

This report describes the design of an Assisted GPS system that holds an exchange of information with an assisting server and computes its position after receiving the necessary data. Along the following chapters we present our algorithm for solving the coarse time error and computing the pseudoranges. The report also presents a short description of the equipment used and an explanation fo the way in which the communication works. 

2008

Matlab Tool for Studying the GPS Constellation

By: José Juan Cruz Martínez 

The aim of this project is to analyze the effect of closely-collinear measurements on the accuracy of receiver positions. In the project, processing procedures are described, and main results are provided in terms of standard deviations of position solution cartesian coordinates. Testing model was implemented for one epoch to later on apply the same methodology on measurements collected from a RINEX file over a day period. Approximately three thousand positions were recorded. The results indicate that closely-collinear measurements have a limited influence on position accuracy. 

2007

Wi-Fi For Indoor Positioning - Basic Considerations

By: Justas Gailiūnas, Justinas Greibus

IGPS is an outstanding system, but it has an important limitation — it is unavailable indoors. As one of the best suggested improvements is integrating Wireless LAN indoor positioning solutions into GPS and making really global system. This document analyzes what quality of positioning indoors can be achieved using Wi-Fi technology and some portable universal device like a laptop or a PDA. Our project involves distance evaluating experiments as well as position computation in 8x5m. size room using 4 home-use class Access Points and a HP laptop. In addition some of inconvenient (usually causing errors) scenarios are also disputed. A few improvement ideas

2006

GPS Positioning Setups

By: Isaac Nii Noi Tetteyfio, Volodymyr Petrovskyy, Vyachslav Tretyak and Gediminas Veiverys

In this report we explore and present the efficiency of different GPS positioning methods. Starting with the single point positioning we move on to double differencing, additionally showing results of Doppler shift data processing. Mathematics for these methods as well as Matlab code implementation are shown. Comparison of results obtained using different methods drive our conclusions of best choices for speed or accuracy demanding applications.

2005

EGNOS Augmented GPS and SISNeT Interface

By: Dominykas Barisas, Kazimieras Bagdonas, Christian Have Pedersen

After GPS became available, many different methods for position improvement were developed. However, users required better accuracy and availability of this positioning service, therefore developments were made. One of them is SBAS which is based on regular GPS and geostationary satellites which broadcast correction data. EGNOS provides augmentation data for the European continent and to improve the availability of the augmentation service, SISNeT is being developed. The aim of this project is to analyze EGNOS and SISNeT and apply correction data to GPS measurements based on C/A code. An interface of SISNeT was developed and verified. The interface and correction estimation and application were implemented in Matlab and Java. The accuracy of the observed GPS raw data was improved using different sources of EGNOS messages and compared with each other and the position and data from a commercial EGNOS receiver.

2004

Real time GPS/GIS Mapping

By: Kostas Dragūnas, Stephen Kwabena Kportufe and Vitalijus Linikas,

The project describes how GPS and GIS technologies are used to create a system for real time mapping of local area (Aalborg University). It employs the concept of Differential GPS to accurately observe the positions of geographical objects and collect attribute information. A radio link is used as a communication medium between the roving GPS receiver and the reference station. A map is then created and visualized in real time wilth the help of PDA via internet connection. Computations of object positions are done by the help of Matlab. Same important programming tools used for map visualization in this project include: SVG, PHP, and JavaScript. All data is stored in PostgreSQL database, which also serves as rniddleware between system components.

Performance Analysis and Implementation of Conventional and EGNOS-based DGPS Setups

By: Anders Skeie, Sarfaraz Anwar Khan, Usman Ahmed Zahidi and Xiangfu Meng

The need of accuracy in finding a precise position using GPS, led to the development of several error correction techniques. A differential setup uses at least two receivers; the reference and users' receivers. The coordinate of reference receiver is known while the users calculate their position with respect to the reference. The user applies corrections by differencing with respect to the reference to eliminate the possible ionospheric, tropospheric, clock or other miscellaneous errors. The fact that these erroneous factors are similar when the receivers are closer to each other, differencing ensures removal of errors, hence improving accuracy. The limitation of closer range of receivers for differential corrections led to the development of Satellite-based augmentation systems (SBAS) that have multiple reference stations across a wide area and a master reference station, which broadcasts the corrected observations through the geo-stationary satellites. In this project we implemented the SBAS and local area DGPS for static and kinematics modes. A comparison of accuracy on the basis of different modes and setups is presented in this report.

2003

Analysis and Implementation of Differential GPS Setups

By: Angel C. Alvarez, Darius Plaušinaitis, Frank K. Ocran, Nicolaj Bertelsen, Peter Rinder, and Saulius Pušinskas

The introduction of the global positioning system (GPS) offered a completely new area of wonderful and precise navigation. As more applications for this system appeared, the need for more precise positioning accuracy arose. This project is focused on investigation some of the different DGPS techniques available, implementing them , and running a series of tests. Doing this will show how each technique works, how they perform when implemented, and how they deal with the existing errors that decrease accuracy. The system was implemented both in real time and post processing mode. A comparative scenario between techniques was created by statistical data. A common setup consisting of one reference station and one user receiver was used; the linke between them is by means of radio modem link. This setup allows transmitting differential corrections from the fixed reference station to the user receiver. Test results obtained show how some techniques give better results than others. All techniques were tested under the same conditions. Based on the obtained results, it can be said that some techniques are just not worth implementing in a real system, and that others can be applied according to accuracy needs.

Graphical User Interface for a GPS Receiver

By: Daisy P. Esparza, Ramūnas Dirmeikis, and Jon Johansen Wedel

The obejctive of this project is to develop a user friendly GUI (Graphical User Interface) for viewing processed GPS (Global Positioning System) observables. This will be done for the Ashtech Z-Xtreme GPS receiver using Matlab. Emphasis will be put on how a graphical user interface should be designed when it is going to support two user types (i.e. a basic and an advanced user). The basic user does not know much about GPS while the advanced user knows, uses, and probably develops applications for the GPS. An emphasis will be put on how to make a program which monitors real time GPS data downloaded from a GPS receiver. In order to reach these objectives, the theory of GUI design and single positioning in the GPS is described. The algorithms for the monitor system are created afterwards. The monitor is then developed and the GUI for the monitor is designed and implemented. Finally, the monitor is tested, and changes in the specifications, theory, algorithms, and design are imposed. The result is a GUI with a two window structure supporting each of the two user types. The opening window of the GUI is giving information which the basic user would be interested in, and the advanced user can move from the opening window to an advanced window in order to see advanced information about the observables being processed by the monitor. Furthermore, the GUI is both supporting real time computation of the GPS observables and postprocessing.

GPS Receiver Position from Pseudoranges

By: Marianne Knudsen and Rune Tvilum

This project investigates the problems in computing the position of a GPS receiver by pseudoranges. Based on three different algorithms Iterative Least Squares Solution, Bancroft’s Method, Kleusberg’s Solution)it is determined how to obtain the fastest execution time and most accurate result. It shows that the best solution is obtained by a combination of the methods.

2002

GPS Monitor

By: Stephen Neuman Asamoah and Tue Klaus Kyndal

Real-Time Monitoring of GPS satellites has become an important task for the past decade. This is because the technology is proliferating rapidly worldwide. The removal of Selective Availability further increased the appeal of GPS. This reprot contains discussion of the importance of Real-Time Monitoring of GPS and the procedure used in realising this in practice. Matlab was used mainly to establish communication with Ashtech Z-Xtreme receiver. The same medium was used in handling and processing data. Several fields of GPS were included in the monitor. They are: Orbit of Satellite, Satellite Health, Signal to Noise Strength, Receiver Position, Dilution of Precision, and Prediction of available satellites above the elevation mask for the current day. It can be stated that the system worked according to specification and if modified could be adopted for professional use. Download project.

2001

Combine a Mobile Phone, a GPS Board, and Thermometer

By: Mindaugas Stonys, Mindaugas Paukštė, Jevgenij Gagac and Inga Paulauskaitė

This project is about the design and implementation of a mobile system, which is based on GPS and GSM Technology integration. The purpose of this system is to track moving objects. Such a system makes it easy to gather geographical position data along with additional information about moving object. The system has been designed using PIC microcontroller and implemented in assembly language code for Microchip’s PICmicro microcontroller families. The result is a running system, which is capable to send geographical position data and temperature from moving object to an ordinary GSM mobile phone using SMS messaging service.

2000

Combined GPS Card and Mobile Telephone measuring Temperature

By: Adeniyi Hakeem Iyiade, Darius Popovas and Kristina Radzevičiūtė

Today the satellite navigation technology, with its capability to provide accurate position information, plays a key role for a more efficient management of the available transport resources. Thanks to GPS, the management of various transport kinds (ships, aeroplanes, busses, cars, trucks, trains and trams) can be optimized in order to reduce travelling times and decrease fuel consumption hence lowering operative costs. A GPS receiver, fitted to a vehicle, is able to constantly and accurately determine its location, providing fixes every few seconds. Our project was made in case to show the extensive opportunities of using GPS receivers in the managing of transportation of frozen products. So our investigation was undertaken in advance to implement a System, which gets the actual position of the conveyance with the help of GPS receiver, makes measurements of the temperature and sends the SMS message about the location and condition of refrigerator to the control station. Concerning to the time limit and the large volume of work, which was needed to finish up the project, we’ve gotten the opportunity to reduce the project by building the system with connections only between GPS receiver, Liquid Crystal Display (LCD) and temperature sensor. This document is the first in the development of PIC project, an implementation of a combined GPS receiver and a temperature measurement using a PIC millennium board. The objectives of this project is to use the Motorola’s GT plus Oncore GPS Receiver in an embedded application and to build a user-friendly GPS system, which would display the position of GPS antenna and the temperature on a LCD. The micro controller, we have used for interfacing between GPS and LCD, is the Microship’s PIC16F84. The project was approached first by interfacing the GPS receiver to the LCD via the parallel port, then coding a program to read the temperature via the temperature sensor in the PIC board and display it on the LCD. We have used a micro controller as a transmission point between GPS and LCD (temperature sensor & LCD). By studying the protocols of the GPS and LCD, a program for the micro controller was implemented in assembly language.

GPS and Meteorology

By: Saulius Prizginas and Audronė Kvedarienė

The purpose of this project is to make the acquaintance how GPS radio signals collected by a ground-based geodetic GPS receivers can be used in meteorology for estimating vertically integrated water vapour, or precipitable water and to analyse the data received from GPS using the software package, GAMIT - suite of programs developed at MIT and Scripts for estimating station coordinates, orbital parameters, Earth orientation, and atmospheric parameters from the carrier beat phase recorded by geodetic GPS receivers. The main emphasis will be on atmospheric parameters, for evaluating the atmospheric delay in troposphere due to water vapour.

GPS and Digital Map

By: Dalia Prizginienė and Kofi Owusu Nkansah

Trying to figure out where you are and where you are going is probably man’s oldest problem. Navigation and Positioning are crucial to so many activities and yet the process has always been quite cumbersome. Over the years all kinds of technologies have tried to simplify the task but every one has had some disadvantage. The best way to get to where you are going is to know where you are going. If you are lost in unfamiliar territory, you can pull out a map and try to find out where your destination is relative to you. But the question is, what if you don’t know where you are on the map? Maps have always played a special role in the history of mankind and for most people, the map is the most widely used device for answering most of our navigation problems. But the foregoing scenario had proved that in navigation maps could be completely irrelevant if you don’t know your position on the Earth. This is where Global Positioning System (GPS) comes into play. Whit GPS, ones position on the Earth at any point in time could easily be located. That is why we think the integration of maps with the GPS is a major step forward in our navigation activities and must be hailed by all and sundry. This project dilates on the integration and some of the areas it could be applied.

Useful links:

> Project library

Danish GPS Center, Fredrik Bajers Vej 7C, DK-9220 Aalborg Ř, Denmark, Tel +45 9940 8362, E-mail: gpscenter(at)gps.aau.dk