Research Proposal
UDB301 – Research Methods

Due Date: 30/05/2014
Name: Dylan Black
Student Number: N8304271
Course Code and Major – UD40 – Spatial Science
Email: Dylan.Black@connect.qut.edu.au
Due Date: 30/05/2014
Name: Dylan Black
Student Number: N8304271
Course Code and Major – UD40 – Spatial Science
Email: Dylan.Black@connect.qut.edu.au

The Change Galileo Will Make to RTK Surveying

This study is focused on what will change with the construction and implementation of a new Global Navigation Satellite System called Galileo. The new Galileo system will bring many changes to many different sectors however the change to Real Time Kinematic Surveying and surveyors is the main purpose of this report. Understanding how current systems work and how Real Time Kinematic surveying is undertaken will help in understanding how things will change and what is to be expected with a new system. This study is important as many surveyors and surveying businesses will need to prepare for the influx of new technology as well as assess what they will be able to use the new system for.

Key Words: GNSS, Galileo, RTK, GPS, Surveying

Contents 1.0 Introduction 3 1.1 Image 1 – Galileo Constellation 3 2.0 Literature Review: 4 2.1 History: 4 2.2 Why we launch satellites: 4 2.3 What satellites do? 4 2.4 How do satellites and RTK work: 5 2.41 Diagram 1 – RTK Set Up 6 2.5 Current systems in place: 6 2.6 Problems with current systems: 7 2.7 Why is Europe launching Galileo? 7 2.8 How it will affect RTK surveying: 8 2.81 Combined GNSS Visibility including Galileo 9 3.0 Aims and Objectives: 10 4.0 Significance, Expected Outcomes & Benefits: 10 5.0 Methodology 11 5.1 Research design: 11 5.2 Data Collection Procedure: 11 5.3 Data Analysis: 11 6.0 Project Timeline 12 6.1 Table 1 – Project Timeline – Tasks and Week 12 Bibliography 13

1.0 Introduction

In the last decade the use of Global Navigation Satellites Systems (GNSS) to carry out surveys using Real Time Kinematic (RTK) methods has increased dramatically because of its effectiveness in completing certain surveys in shorter periods of time to a fairly high accuracy. It has allowed single surveyors to complete tasks in one day that originally would have taken many people to do in weeks. There are many applications that use the current GNSS in place such as GLONASS and GPS in all sectors such as transport and aviation.

This increase in demand and use of the systems adds pressure to the infrastructure in place but it also brings out the weaknesses and faults thus giving researchers and government’s reasons to produce newer and better systems one of these being the Galileo system. At this point in time RTK is only accurate to the centimeter in best case scenarios and surveyors constantly desire a higher accuracy. There are still areas where surveyors cannot complete work to an acceptable accuracy such as around and in cities or urban canyons or highly dense forest.

Rizos states that “perhaps the most exciting impact on the future of GNSS is the decision by the European Union to launch its GALILEO project (Rizos, 2007). This new GNSS system will bring many benefits to many different sectors and it will consist of 30 MEO satellites in 3 different orbital planes at 120 degrees at an altitude of around 23,000km with a ground repeat of 10 days at an inclination of 56 degrees. (Moore) Galileo is said to be in full orbit by 2019 and what isn’t known is what benefits or changes it will make to RTK surveying and how it will differ from the existing systems already in place. This study will be focused on determining the change and what surveyors can expect from the implementation of Galileo and if it will be the change they need to fix current issues in RTK surveying.

1.1 Image 1 – Galileo Constellation

Image Source: (Huart, 2002)
2.0 Literature Review:
2.1 History:

The very first satellite ever launched was called Sputnik 1; it was launched in 1957 by The Soviet Union. NASA followed suit with their first satellite being launched in 1958, which was called Explorer 1. The main component of the Explorer 1 was a sensor that measured high-energy particles called cosmic rays. A couple of years later NASA sent another satellite called Explorer 6 which sent back the first satellite pictures of earth. In 1960 TIROS-1 sent back the first TV picture of earth, the pictures weren’t of great detail but they did determine the benefits and the potential this technology had. (Stillman, 2014)

Real time kinematic techniques were implemented for wide use in 1993 once the advancement in technology allowed there to be a link between base and rover GPS receivers. There were still many issues with the systems such as not having the correct initialisation, reliable communications, usability and range. Over RTK’s advancement these issues were knotted out but problems with range continued to be an issue. It was however obvious that this technology was going to be hugely effective and useful for many different things. (Roberts, 2011)
2.2 Why we launch satellites:

Satellites for years have helped people gather and measure information about the earth as well as outer-space. A satellite is a machine that orbits the earth using our gravitational force just as earth orbits the sun. The earth and moon are what we call natural satellites, there are many artificial or man-made satellites orbiting earth. There are many uses for satellites which help the human race ever day. (Stillman, 2014)

2.3 What satellites do?

Satellites do many things depending on the components inside of them and what the intended purpose of any particular satellite is. Satellites do many things such as take pictures of the earth which help meteorologists predict the weather or track hurricanes. They can also measure information about the ocean, land, ice and gases in the ozone. In disaster instances they can monitor things such as wildfires, cyclones and volcanoes as well as helping emergency crews respond to these instances. Others may take pictures of other planets, the sun, black holes in space, dark matter, faraway galaxies or other space objects. It has helped scientist better understand our own solar system as well as more about the universe.

Other satellites are used for communications such as relaying TV signals or phone calls around the world. Before satellites were in orbit TV signals didn’t reach very far and could only travel in straight lines, so they would trail off into space instead of travelling with the earths curve along with mountains and buildings and other features blocking them. This also made phone calls over long distances difficult so with satellites this problem was fixed as well as saving a lot of money having telephone wires run over long distances or underwater. Now signals can be sent straight up to satellites and the satellite can relay it down to different locations on earth. When there is a cluster of more than 20 satellites it’s called a Global Positioning System (GPS) and with a GPS receiver satellites can help people determine their exact location and when more advanced their elevation. The real benefit is the amount of data a satellite can record from its birds-eye view and how quickly it can do it compared to ground instruments.

When looking into space satellites can record better pictures as they are above the earth’s clouds, dust and atmospheric molecules which block our site from the ground.

Other satellites monitor dangerous rays coming from space towards earth, and then there are others that look at asteroids and comets. It is obvious that satellites have many benefits to the human race. (Stillman, 2014)
2.4 How do satellites and RTK work:

Satellites come in many shapes and sizes but most have two parts in common, a antenna and a power source. The antenna is what sends and receives data, mostly to and from earth. The power source is either a battery or solar panels which use the sun to power the satellites components. Other components in satellites include different types of sensors and cameras. Almost all satellites are launched into space on rockets and they orbit the earth when its speed is balanced by the earth’s gravitational field. If there wasn’t a balance then the satellite would either fall back to earth or out into space. Satellites can have different heights, speeds and paths the two main orbits are called geostationary and polar. Geostationary orbit is when a satellite travels from west to east over the equator and moves at the same speed the earth is spinning therefore from earth it seems as the satellite is sitting still. A polar orbit is satellites travelling in a north-south direction and as the earth spins underneath the satellite scans the whole globe strip by strip (Stillman, 2014). The signals that get emitted from satellites are microwaves containing time of transmission and its orbital position. The minimum amount of satellites that one must be connected to, to receive a correction is four. Three of these are used to trilateralise which is the equivalent to triangulation but three dimensional, which determines the user’s longitude, latitude and altitude on the earth. The fourth is to determine the time offset between the satellite clock and the clock in the user’s receiver. (European Space Agency, 2011)

Real time kinematic (RTK) GPS works using carrier phase signals from signals to measure observations of positioning and height. With this method of positioning job time’s area massively reduced to a fairly acceptable level of accuracy. To obtain good accuracy to a standard that’s going to be accepted by consumers at least 5 satellites must be observed simultaneously. Since the advancement of GLONASS and the current GPS system this is not a strenuous task in a lot of cases, however once around urban canyons or other obstructions it can prove difficult.

2.41 Diagram 1 – RTK Set Up

Source: (Mekik & Arslanoglu, 2009)

Above is a diagram of a typical RTK GPS structure which is most widely used throughout RTK surveying. It consists of a reference receiver that is set up on a known point and it sits stationary during the whole survey while the rover receiver moves around recording points. These receivers are duel frequency and use the L1 and L2 signals emitted from satellites. Both receivers must have a radio component, usually on the reference receiver its external which allows for a wider range survey to be done and the rover receiver usually has an internal radio, the radio allows for there to be a link between the reference and rover receiver. The radio link allows for corrections to be send to the rover every 0.5-2 seconds. The correction sent through the radio is unique for each manufacturer in whatever desired format they have chosen to prevent confusion between systems as well as being within the standard set by the Radio Technical Commission for Maritime Services. (Mekik & Arslanoglu, 2009)

2.5 Current systems in place:

2.6 Problems with current systems:

2.7 Why is Europe launching Galileo?

The new GNSS being developed by Europe is the counties answer to providing a high accurate, global positioning service run by civilians instead of the government or military. (Princeton University)

There are many reasons why Europe needs or wants to build this infrastructure, the first being political reasons. Galileo will become critical infrastructure to people and companies around the world that rely on GPS. It will provide jobs as well as giving Europe some competitiveness in this sector. (Moore)

The European Union has realised the benefits of constructing their own GNSS system to support future advances as well as lower their reliance on other systems already in place. They have negotiated with the United States to have their system be able to work in conjuction with the existing GPS system so that both systems broadcast L1 and L5 signals for future GPS/Galileo equipment. Galileo as a GNSS has the potential to leap frog the existing GPS and GLONASS systems whose technology is slowly becoming outdated and unable to provide a 100% uninterrupted service. Galileo will broadcast more singals then any other GNSS meaning that it will be able to support many different applications and be much stronger then existing signals from other systems. The stronger signals will be less susceptable to mulitpathing which is a problem with current signals which causes accuracy and precision to become unacceptable or usable. (Roberts, 2011)

2.8 How it will affect RTK surveying:

The initial impacts for RTK surveying is that current technology will not be able to use the new signals that will be available in the future with modernised GNSS. In 2020 the L1 (C/A) and L2 (P/Y) will be discontinued and everyone will have to upgrade to the new signals meaning new technology will have to be bought to be able to cater for this change. It is likely that once this happens more manufactures will be able to enter the market as patents on the current signal will lose their power which in turn is expected to drive the price of high precision equipment down. Some parts of equipment will have to change such as the antenna to accommodate the new signals being broadcasted but most equipment will end up being more affordable. (Roberts, 2011)

The new signals will be much more powerful and more satellites means a stronger solution will be able to be recorded. Also once Galileo becomes available many more satellites will be in orbit meaning that losing signal when performing surveys will be less likely if not eradicated completely. Australia is well positioned for the future GNNS which is obvious in the image below: (Roberts, 2011)

2.81 Combined GNSS Visibility including Galileo

Image Source: (Roberts, 2011)

The above Image shows how many satellites will be able to be visible all around the world. The different colours represent different amounts of satellites, which show that Australia is in a fairly good position compared to the rest of the world with an average of 37-46 which is a very high amount in comparison to available satellites at present.

Some of the benefits of Galileo have been outlined by Professor Terry Moore from the University of Nottingham. He has said Galileo will improve GPS acquisition, which is the time it takes the equipment to initialize before you can start recording points. Also tracking will be improved meaning moving objects such as cars, aircraft and surveyors walking around with receivers will be less susceptible to signal dropouts. Multipath performance will be improved making urban canyons and high density areas on earth easier to survey especially with improved building penetration. The reason for all these improvements is for several reasons listed below:

* Wider bandwidths * More available frequencies * Improved BOC modulation schemes/High Chip Rate * Improved coding on signals * Pilot tone

Another big improvement will be the dual civil frequencies which permit ionospheric uncertainty and support CP ambiguity resolution. (Moore)

The next generation of GNSS will rely on differential mode of operation where multiple frequencies can be processed by receivers. The impact of this being implemented there are three main areas that will change for surveyors which are stated below.

* Enhanced Accuracy * Improved Availability * Higher Integrity

The reason accuracy is enhanced is because more observations can be taken, greater measurement redundancy is present and lower dilution of precision. Availability is improved because of how many satellites are visible, the availability of dual and triple frequencies and faster ambiguity resolution. Integrity is improved by having a high measurement redundancy, minimised interference vulnerability as well as enhanced algorithms. (Dempster & Rizos, 2009)
3.0 Aims and Objectives:

The aim of this study is to identify the changes in RTK with the introduction of the new Global Network Satellite System Galileo.

Objectives: * Investigate current precision & accuracy of RTK surveying. * Identify weaknesses & gaps in current RTK surveying * Identify benefits & outcomes from the introduction of Galileo on RTK surveying.
4.0 Significance, Expected Outcomes & Benefits:
Since the popularity of RTK surveying has greatly increased over the years with new technology and Global Navigation Satellite Systems (GNSS) there are many people that will need to be readied for the change Galileo will bring to the industry. Since surveyors aren’t particularly concerned with the new signals or how manufactures have to change their technology this study will provide knowledge on what they need to know and expect to come.

This study is important for surveyors so they can prepare for the influx of new technology and processes that Galileo will bring. Galileo is still in the implementation phase so therefore now is the best time to try and understand what will change before it actually happens. This will be most beneficial to older surveyors so they can also start preparing and understanding the differences to come.

It is expected that this study will help surveyors in understanding the future for RTK surveying, not only for them to practice but also for business’s to ready themselves for the new technology and knowledge of where the profession is leading.

5.0 Methodology
5.1 Research design:
This is a cross sectional, descriptive study that is focused on the changes Galileo will make to RTK surveying.

5.2 Data Collection Procedure:
As the satellite is only scheduled to be launched and fully operation in 20129, this will be a comparative review of expected outcomes & benefits of Galileo using secondary data obtained from academic journals and industry websites.

I will be looking at respected websites and journals such as: * The official NASA website * The European Space Agency Website * Journals from Heads of Spatial Science from all Universities as well as from respected professors * The InsideGNSS website which is the biggest GNSS community with active and up to date information. * The European Global Navigation Satellite Systems Agency website also has comparative data and lots of information about Galileo * A website called GPS World which is also another huge and well respected source of information

The information I will be able to gain from these sources will mainly be tests and simulations the Galileo system has gone through and how it compares to existing systems. I will also be able to find what kind of expectations and accuracy can be expected with all Galileo and current systems working congruently. There will also be information on how technology will change for surveyors to accompany the new and improved signals. The main data will be the comparisons between existing systems and Galileo as that’s the most important data that surveyors will be concerned about and also the main indicators on how RTK surveys will change.

5.3 Data Analysis:
Comparing current available data & projected/modeled future data.
Outputs of this data analysis will include: * Difference in precision and accuracy * Future number of available satellites * New signals * Change to RTK
This will be used to increase awareness of how the introduction of Galileo will impact on surveys using RTK techniques.

6.0 Project Timeline

This project will be undertaken in the second semester 2014. The table below shows when each task will be undertaken and how much time will be needed for each task. Once data collection has been completed then the data analysis can begin and then following analysis the write up can begin. Its expected data collection will take a while as it’s a fairly new topic that’s not fully operational yet.

6.1 Table 1 – Project Timeline – Tasks and Week

Task/Week | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | Research Question | | | | | | | | | | | | | | Methodology | | | | | | | | | | | | | | Literature Review | | | | | | | | | | | | | | Data Collection | | | | | | | | | | | | | | Data Analysis | | | | | | | | | | | | | | Write up | | | | | | | | | | | | | | Final Draft | | | | | | | | | | | | | | Submission | | | | | | | | | | | | | |

Bibliography
Bays, K. (2014). Considerations for Testing Glonass. NGS 'Best Practices for RTn Administration' Webinar. Oregon: Oregon Department of Transport.

Dempster, A. G., & Rizos, C. (2009). Implications of a "System of Systems" Reciever. All Pages.

European Space Agency. (2011). Birth of the European Satellite Navigation Constellation. All Pages.

Huart, J. (2002, May 14th). Galileo Constellation. Retrieved May 30th , 2014, from European Space Agency: http://www.esa.int/spaceinimages/Images/2002/05/Galileo_constellation

International Committee on GNSS. (2008, July 14th). COMPASS/BeiDou Navigation Satellite System. Retrieved May 22nd, 2014, from http://www.oosa.unvienna.org/pdf/icg/2008/expert/2-1a.pdf

Mekik, C., & Arslanoglu, M. (2009). Investigation on Accuracies of Real Time Kinematic GPs for GIS Applications. Remote Sensing, 24-25.

Moore, P. T. (n.d.). Nottingham Geospatial Institute. Retrieved May 21st, 2014, from Galileo: http://www.gfg2.eu/sites/gfg2.eu/files/Gfg2_Terry%20Moore_Galileo.pdf

Princeton University. (n.d.). Global Navigation Satellite System. Retrieved May 21st, 2014, from https://www.princeton.edu/~alaink/Orf467F07/GNSS.pdf

Pullen, S. (2007). Worlwide Trends in GNSS Development and their Implicatoins for Civil User Performance and Safety. 2-5.

Rizos, C. (2007). The Future of Global Navigation Satellite Systems. University of New South Wales, School of Surveying & Spatial Information Systems . Sydney: University of New South Wales.

Roberts, C. (2011). How will all the new GNSS signals help RTK surveyors? All pages.

Stillman, D. (2014, February 12). What is a satellite? Retrieved May 15, 2014, from Nasa: http://www.nasa.gov/audience/forstudents/5-8/features/what-is-a-satellite-58.html#.U3Q1QhBfZGA