Report on GNSS Surveying and Data Collection at Flinders University

This report presents an analysis of surveying the Flinders University land area using three methods: smartphone GPS, Survey123, and GNSS (Global Navigation Satellite System). The study details the procedures for data collection using each method, including setting up equipment and recording data. Results from each method are presented, including error calculations. The discussion focuses on the error sources inherent in GNSS technology, such as system errors, signal propagation errors, and clock-related errors, and suggests mitigation strategies. The report concludes that while all methods allow for estimating the position of various points, GNSS is the most accurate due to its use of multiple satellites, enabling precise positioning. The report highlights the diverse applications of GNSS technology in navigation, surveying, and military uses. Desklib provides access to this report along with a wealth of study tools and resources for students.

Geography Report
Flinders University Area
Introduction
GNSS or Global Navigation Satellite System is group of satellites that are providing signals from
space that transmit exact positions and data to GNSS receivers in any location. We thereafter use
the received data to determine locations accurately.
GNSS was commissioned and is operated by the United States department of defense in the
name of NAVSTAR Global Positioning System, Europe’s Galileo, Russia’s GLONASS and
China’s BeiDou Navigation System. This satellites give global coverage. These GNSS satellites
use a constellation of orbiting satellites in space which transmit signals to stations here on earth.
The GNSS use triangulation and setting up of spot heights to locate various points. This involves
complex calculations involving data from various satellites. The whole process starts when each
satellite sends signals which is received by our GNSS receiver. The signal is then interpreted by
the receivers and converted information into position, velocity and time. Using this information
and coordinating of various data from different satellites helps to determine exact position.
In surveying the Flinders University’s land area, we used three methods in recording the data.
These methods were; one, use of smartphone, two, using survey 123 method and lastly use of
GNSS device.
Methods
The data collection was done by setting up the equipment needed for the study. We ensured that
we had the smartphone, DNSS machine and installed application which will be used in collection
of data of Flinders University area. (Berg, 2011)
We used three methods in collecting data of the land area of Flinders University. These methods
were survey 123, use of smart device and the GNSS.
In collecting and recording data using survey 123 we first the survey 123 form using a computer,
downloaded the survey 123 software application and the signed in. we then clicked on the ‘new
survey’ icon and created a new survey. We titled the survey as Flinders University and saved.
We thereafter retrieved the form we initially downloaded from the computer into the software
and the excel files and clicked open input. We then published survey by pressing the publish icon
(Naciones Unidas. División de Estadística, United Nations. Statistical Division, 2005).

In using the phone, we chose a phone with A-GPS installed in the phone. The smartphone’s
antenna had preset control points of locations already surveyed and verified. We set the phone as
a control GPS which was to locate our receiver, we measured and plotted the survey using the
system that we set.
In using the GNSS method, we used a software defined GNSS receiver. The receiver was
connected to a smartphone. We set the GNSS by using a handheld small digital antenna which
was detected on our GNSS receiver. The accuracy of this method ranged from meter level to
centimeters. We the collected data of various spot points within the Flinders University are and
recorded.
After collecting data, we then recorded it by tabulating it three forms; one data collected using
the smartphone, using manual survey and using the GNSS instruments. We also calculated errors
and recorded them.
Results
Phone
The data collected by use of phone was recorded using a table as shown below. Measured error
and elevation error were calibrated as well.
GNSS
Results of the study done by the use of the GNSS equipment were recorded and calculated as
shown below. The various errors such measure error were calculated and recorded as well.

Survey 123
The data collected was recorded in the survey 123 form as shown below. Survey 123 error and
elevation error were calculated and recorded as well.
Discussion
GNSS signals usually have low power levels. And as it can be seen from the above result table,
this method is thus prone to various errors. These are errors include system errors, signal
propagation errors and clock related errors (Tétreault, 2010).
System errors result from the overall nature of the DNSS instrument and the shape of the orbital
planes. Errors such as orbital plane arises when our receiver is calculating the position of the
satellite using information contained in the navigation message called satellite ephemeris. This
type of error can be mitigated by using local network correction systems for the satellite.
Errors related to satellite or receiver clocks is caused by the DNSS receiver using crystal clocks.
This type of clocks has very low accuracy and thus causing errors. It can be mitigated by external

clocks usually made up of Cesium or Rubidium which have higher performance unlike crystal
ones (Aponte, 2009).
Errors caused by signal propagation include sagnac effect error. This error is caused by the
earth’s rotation when the signal is being transferred from the satellite to the DNSS receiver.it can
be corrected by using global or local dual frequency receivers.
Despite the errors seen in all methods used in surveying of the University, GNSS is proved to be
a better method as compared to other methods and is the modern one.
Summary
Using the three methods namely phone, survey123 and GNSS one can be able to estimate
positioning of various points of Flinders University. But we observed that GNSS method is the
most accurate of the three methods. This is because it incorporated many satellites in giving
almost exact position of various spot height within the University.
The services provided by the GNSSS navigation instruments can be used in various uses, both
military and civilian. They include navigation, where both civilian and military can use the
GNSS system to find their way in airplanes and ships. A GNSS equipment can be used by the
visually impaired.
The GNSS is used also in surveying and mapping. In addition, the equipment can be used by
military in precision-guided munitions in guiding munitions such as missiles to their target. Also
this type technology can be applied in mobile satellite communication.

References
Aponte, J. X. M. C. H. T. M. M. B. a. A. D., 2009. Quality Assessment of a network based GPS
System in the UK. Journal of Applied Geodesy, Volume 3, pp. 25-34.
Berg, R. a. T. H., 2011. Precise Point Positioning Accuracy Analysis for. Ontario Professional
Surveyor, 54(2), pp. 32-37.
Naciones Unidas. División de Estadística, United Nations. Statistical Division, 2005. Guide to
Producing Statistics on Time Use: Measuring Paid and Unpaid Work. illustrated ed. New York:
United Nations Publications.
Tétreault, P. a. P. S., 2010. CSRS-PPP: A web tool to facilitate NAD83(CSRS). CSRS-PPP: A
web tool to facilitate NAD83(CSRS), 53(1), pp. 26-30.