Bachelor Thesis
German Title: „Untersuchung eines 'ray tracing' Programms auf seine Eignung für die Kurzwellenfunk-Ausbreitungsprognose“
Structure of Presentation
• Task of the Thesis
• Proceeding
• Summary of relevant results
• Discussion
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Task of the Thesis
In German:
„Detaillierte Untersuchungen des 'ray tracing' Programms 'Proplab-Pro 3.0' auf seine Eignung für die professionelle Kurzwellenfunk- Ausbreitungsprognose“
In English:
“Detailed Examination of the ray tracing Software 'Proplab-Pro 3.0' on its suitability for the professional forecast of HF-radio propagation”
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Proceeding
• Study of ionospheric HF-propagation basics
• Manual calculation of a representative HF-link
• Study of "Ray Tracing" basics
• Comparison of three propagation simulation SW "PropWiz", "RPPUE" and "Proplab-Pro 3.0" w.r.t.
• Features
• "Truth" of results
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Basics
of
Ionospheric HF-Propagation
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Basics of Ionospheric HF-Propagation
HF propagation modes:
• Groundwave
• Skywave
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Basics of Ionospheric HF-Propagation
Skywave propagation paths:
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Basics of Ionospheric HF-Propagation
HF skywave propagation via ionosphere depends on the following factors:
• Time of day
• Season
• Geographic location
• Solar activity
• Frequency
• Antenna elevation radiation angle, corresponding with angle of incidence of the wave into the ionospheric layer
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Basics of Ionospheric HF-Propagation
Ionospheric layers:
•F-layer (subdivided in F2- and F1-layer)
•E-layer
•D-layer
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Manual Calculation of a representative HF-Link
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Manual Calculation of a representative HF-Link
Calculation of the usable frequency range for two exemplary paths:
1st path: Munich – Hamburg
2nd path: Munich – Hong Kong
Both paths were calculated for the points in time
July 2012 and
January 2013
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Manual Calculation of a representative HF-Link
Path Munich – Hamburg:
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Manual Calculation of a representative HF-Link
Path Munich – Hamburg:
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"Ray Tracing" Basics
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"Ray Tracing" Basics
Basically the term "ray tracing" in English language is self explanatory.
Somewhat more in detail it means:
• Emitted electromagnetic waves are described by "ray tracing" using idividual rays
• The course of the rays is simulated obeying physical laws, angle of emission, diffraction and absorption
• In this way the various incident points of the wave at the ionosphere and at ground are found
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"Ray Tracing" Basics
In the "Proplab-Pro 3.0" software the "ray tracing" model
• calculates how the signals penetrate the ionosphere and propagate in it. Penetration and diffraction are the keywords
• traces each ray individually using a dynamic, very complex model of the ionosphere
• allows for the actually existing ionospheric conditions
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"Ray Tracing" Basics Characteristics of the "ray tracing" models in "Proplab-Pro 3.0":
2D-Model 3D-Model
Computing time Fast Suitable for real time analysis
Boring slowly Calc. time: Days to weeks
Accuracy High Very high
Including … Oblique ground reflections - -
Absorptions by the ionosphere
- Oblique ionosphere layers
Magnetic field effects Absorptions by the ionosphere
Graphic result diagram shows ...
Elevation Frequency
-
Elevation Frequency Azimuth
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Comparison of three Propagation Simulation SW
"PropWiz", "RPPUE" and "Proplab-Pro 3.0"
as well as
Manual Calculation
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Overview of "Proplab-Pro 3.0", "PropWiz 1.7" and "RPPUE
4.28" Proplab-Pro PropWiz RPPUE
Full
Name
Proplab-Pro Propagation
Wizard
RPPUE, Program for
calculation of HF
Radio Propagation
Predictions
Supplier Solar Terrestrial
Dispatch
Rohde & Schwarz Dr. Thomas Damboldt
Telecommunications
Version Version 3.0 Version 1.7 Version 4.28
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Features of "Proplab-Pro 3.0"
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Features of "Proplab-Pro 3.0"
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Analysis of Results
Comparisons between:
1. Basic Data
2. MUF resp. FOT
3. SNR
4. Fieldstrength resp. signal strength at Rx site
5. Availability resp. reliability of commline
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Analysis of Results
1. Basic Data e.g.
– Site Coordinates
– Distance
– Azimuth of Tx- resp. Rx- antennas
– Minimum number of required hops
Result:
No relevant differences between examined programs
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Analysis of Results
2. MUF resp. FOT comparisons shown for the 2nd exemplary path Munich - Hong Kong in July 2012
Result: RPPUE results show very good coincidence with manual
calculation PropWiz calculates more pessimistic (i.e. lower) MUF-
values (deviations up to 3.7 MHz) Proplab-Pro 3.0 shows clear differences (deviations 2,5
MHz to 6.9 MHz) → MUF determination by "ray tracing" → more actual and precise resultats
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MUF as calculated by PropWiz
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MUF as calculated by RPPUE
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MUF as calculated by Proplab
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Analysis of Results
3. SNR-comparison shown for the 2nd exemplary path Munich - Hong Kong in July 2012
Result:
SNR available only for PropWiz und RPPUE
Course of SNR over time is identical for both programs
S/N absolute values and associated frequencies, however, exhibit major differences
→ algorithms used resp. databases are different
→ Antenna radiation patterns are evaluated with different precision
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Analysis of Results
4. Comparison of Fieldstrength resp. Signalstrength at Rx site shown for the 2nd exemplary path Munich - Hong Kong in July 2012 Result
Available only with programs RPPUE and Proplab-Pro 3.0 Quick and easy fieldstrength determination with RPPUE Proplab-Pro 3.0: rough determination of areas having high
or low signalstrengths; bad recognition of colors and hence signalstrengths; obvious occurence of quantization errors
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Fieldstrength as calculated by RPPUE
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Proplab-Pro 3.0 – Settings
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Proplab-Pro 3.0 – Broadcast Coverage Map
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Proplab-Pro 3.0 – Zoomed Broadcast Coverage Map
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Analysis of Results
5. Comparison of Availability resp. Reliability shown for the 2nd exemplary path Munich - Hong Kong in July
2012
Results: Available only with PropWiz und RPPUE PropWiz is determining the availabilty on the basis of the SNR RPPUE does this on a more lavish way considering technical
boundary conditions and statistical fluctuations within a month
Further Differences are to be traced back by the utilization of different databases
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Further Analysis Tools contained in "Proplab-Pro 3.0"
„Proplab-Pro 3.0“ comes with three analysis tools :
• Ray Location Map
• Broadcast Coverage Map (already introduced in context with signal strength analysis)
• Oblique Sounder Ionogram
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Ray Location Map
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Ray Location Map
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Oblique Sounder Ionogram – Settings
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Oblique Sounder Ionogram – Elevation Angle Plot-
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Oblique Sounder Ionogram – Elevation Angle Plot-
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Oblique Sounder Ionogram -Propagation Delay Plot-
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Oblique Sounder Ionogram -Propagation Delay Plot-
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Summary of relevant Results
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Summary of relevant Results
I. Anforderungen des Benutzers müssen ersichtlich sein
II. Programm auswählen, welches am besten zu den gestellten Ansprüchen passt
III. Vorgehen bei der Auswahl: Analysepunkte sowie Features der Programme auf ihre Wichtigkeit für den Anwender überprüfen
IV. Programm auswählen, welches die meisten Punkte und Features für den Anwender bereitstellt
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Summary of relevant Results
Manual Calculation: The old fashioned, maybe quite accurate, method is nice for getting started and to acquire a basic understanding. Due to the immense time needed, this method nowadays has to be regarded as "pure academic". PS: In the course of our studies we found out that some old but valuable ITU (CCIR/CCITT) documentation is available only in antiquarian form
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Summary of relevant Results
PropWiz and RPPUE: Both programs deliver quick results an are rather simple to be operated. The training period for RPPUE will be longer as compared to PropWiz but due to a more complex algorithm the results will be more precise - and ... more colorful. PS: The antenna database for both programs is of paramount importance with respect to to the meaningfulness of the results.
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Summary of relevant Results
Proplab-Pro 3.0:
– Substantial training period required
– Many features
– Highest accuracy of all due to complex ionosphere-model and application of ray tracing method
– Quantization errors observed
– 3D-model with PCs available at that time due to extreme calculation time not applicable
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Many Thanks for your Attention!
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Discussion
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Manually
Proplab-Pro
Propwiz
RPPUE