Thursday 9 March 2017
Wednesday 8 March 2017
Week 5
The summary of week 5:
The main objective of this week was to combine group A and B's work together as shown in Figure 1 and test the project as a whole.
In order to test the project we had to go outside to track the moon. The group decided on nearby Sefton park, we would pick a secluded spot that would be subject to minimal light pollution and interference from objects like trees. However, during the initial test of the project we faced many issues beyond our control. Some of the difficulties we faced included:
[1] - Met Office, " Liverpool Forecast" http://www.metoffice.gov.uk/public/weather/observation/gcmzggpxq, accessed 4/3/17 then again on 8/3/17
The main objective of this week was to combine group A and B's work together as shown in Figure 1 and test the project as a whole.
Figure 1: combination of the two projects |
In order to test the project we had to go outside to track the moon. The group decided on nearby Sefton park, we would pick a secluded spot that would be subject to minimal light pollution and interference from objects like trees. However, during the initial test of the project we faced many issues beyond our control. Some of the difficulties we faced included:
- The weather was not as forecast. Strong winds, meant it was difficult for the bracket to be free standing and caused movement of the camera which would of lead to blurring of the photographs had we ran the software.
- Moon visibility was also poor. Cloudiness meant there was no clear view of the moon.
- Moreover, Group B's monitor failed. This meant there was no way of testing the project that night, as the monitor is needed to set resolution, number of photos to be taken and time delay. The monitor had been working earlier in the day and we put the failure down to the adverse weather conditions.
Weather forecast and moon visibility for Monday 5th March taken from Met Office website[1]. |
Monitor display on first testing attempt |
No pictures of the moon on the first try just a great team photo! |
However, Team Moon Tracker would try again!
We decided to try again on Wednesday 8th of March. This time the weather was on our side.
We began testing, luckily we did not face the same issues as last time and everything was working as expected.
Both teams agreed to run the program for around 30 minutes at 640x480 resolution taking a picture around every 20 seconds, then again at 1280x720. Team B overlaid each set of photographs obtained, around 50 images each time.
Wednesday 8th March weather forecast taken from Met Office website [1]. |
We began testing, luckily we did not face the same issues as last time and everything was working as expected.
Junkun and Yukang initiating the code for our position. |
Both teams agreed to run the program for around 30 minutes at 640x480 resolution taking a picture around every 20 seconds, then again at 1280x720. Team B overlaid each set of photographs obtained, around 50 images each time.
The final results are shown in the figures below.
Figure 3: 1280 x 720 resolution |
[1] - Met Office, " Liverpool Forecast" http://www.metoffice.gov.uk/public/weather/observation/gcmzggpxq, accessed 4/3/17 then again on 8/3/17
Friday 24 February 2017
Week 4
Summary of week 4 process:
This week the code finally started to take shape. However, due to overloading the uBlox GPS module with a 5V supply we managed to break it. Therefore, we had to use a new GPS module, this time we checked the data sheet and attached it to the 3.3V Arduino UNO pin and modified the code accordingly. Figures 1 and 2 show the old GPS new GPS modules we have been using.
Figure 1: The broken GPS |
Figure 2: The new GPS |
Figure 3: The overall set up. |
Below is the modified code for the new GPS module.
Figure 4 :New GPS code |
Notes and plan for week 5:
- Combine both Team A and Team B's halves of the project.
- Test the circuit outside
Friday 17 February 2017
Week 3
This is the third lab week for the year 2 project and our progress is quite slow. This week we were mainly focused on the calculations. All members of the group where trying to understand the complex algorithms that needed to be implemented into the code which was easier said than done, as it seemed each equation led to another unknown!
A complete calculation was finally achieved by Dominyka! Her entire working is shown below. This demonstrates how complex the algorithm is as all of this working merely shows the position at one specific time on a certain date.
Calculating
the position of the Moon for 05/03/2017 at 11:32. (first quarter) [1]
1) Conversion
of time and date to Julian days
Julian
day = 864000s
Julian
year = 365.25d
Julian
century = 36525d
JD=365.25*year’+30.6001*(month’+1)-15+1720996.5+day+(hour+minute/60+second/3600)/24
If month<=2, then month’=month+1,
year’=year-1,
if month>2, then month’=month,
year’=year.
Number of Julien centuries: T=(JD-JD0)/36525
JD0 is the Julian day for
01/01/2000 at 12:00UT
JD0=365.25*1999+30.6001*14-15+1720996.5+1+12/24=2451546.151
JD is the Julian day for 05/03/2017
at 11:32UT
JD=365.25*2017+30.60001*4-15+1720996.5+5+(11+32/60)/24=2457818.631
T=6272.479596/36525=0.171731132
2) Astronomical
algorithms
·
Ecliptic latitude B and longitude L of the
Moon [2]
B=-5.171º
L=75.062º
·
Convert B and L to right ascension RA and
declination delta
eps=23+26/60+21.448/3600-(46.8150*T+0.00059*T2-0.001813*T3)/3600
X=cosB*cosL
Y=cos(eps)*cosB*sinL-sin(eps)*sinB
Z=sin(eps)*cosB*sinL+cos(eps)*sinB
R=
delta=180/π*arctg(Z/R) //π=180º
delta=180/π*arctg(Z/R) //π=180º
RA=180/π*arctg(sinL*cos(eps)-(tgB*sin(eps))/cosL)
eps=23+26/60+21.448/3600-(46.8150*0.171731132+0.1717311322*0.00059-0.001813*0.1717311323)/3600=23.43705789º≈23.437º
X=cos(-5.171º)*cos(75.062º)=0.2567
Y=cos(23.437º)*cos(-5.171º)*sin(75.062º)-sin(23.437º)*sin(-5.171º)=0.9187
Z=sin(23.437º)*cos(-5.171º)*sin(75.062º)-sin(23.437º)*sin(-5.171º)=0.3
R=0.953926
delta=1*arctg(0.3/0.953926)=17.4578º
RA=arctg(sin(75.062º)*cos(23.437º)-
(tg(-5.171º)*sin(23.437º))/cos(75.062º))=45.73877694º≈45.74º
·
Sidereal time at Greenwich [3]
theta0=280.46061837+360.98564736629*(JD-JD0)
Local time: theta=theta0+longitude(E+,W-)
Hour angle: tau=theta-RA
theta0=280.46061837+360.98564736629*6272.479596=2264555.568
2264555.568/360=6290.432134
6290.432134-6290=0.4321338119
theta0=0.4321338119*360=155.5681723º
theta=155.5681723º-2.963827º=152.6043453º
tau=152.6043453º-45.74º=406.8643453º
3) Final
results
·
Convert tau and delta to horizon
coordinates h(altitude) and az(azimuth) of the observer (53.406773º,
-2.965723º)
sinh=sin(beta)*sin(delta)+cos(beta)*cos(delta)*cos(tau) //beta-latitude
tg(az)=-sin(tau)/(cos(beta)*tg(delta)-sin(beta)*cos(tau))
h=sin-1(sin(53.406773º)*sin(17.4578º)+
cos(53.406773º)*cos(17.4578º)*cos(106.8643453º))=4.353º
az=arctg(-sin(106.8643453º)/(cos(53.406773º)*tg(17.4578º)-sin(53.406773º)*cos(106.8643453º)))=66.285º
·
Compute the parallax in altitude
horParal=r/a
(rad) //r-radius of the
Earth(6378km)
//a-distance
to the Moon(384400km)
Converting
to degrees: horParal=horParal*57.2957795
altParal=sin-1(cosh*sin(horParal))
Apparent
altitude: H=h-altParal
horParal=0.0165921rad=0.9506568201º
altParal= sin-1(cos(4.353º)*sin(0.9506568201º))=0.9479142571º
H=4.353º-0.9479142571º=3.41º
Notes for week 4:
- Finish implementing the code and begin testing.
- Design the poster and discuss what should be included.
Friday 10 February 2017
Week 2
Week 2 process :
We worked as a team to share useful resources we had found detailing the problem and presented individual findings to each other. Some of the processes during this week:
- Detailed
research of the moon position calculation revealed how many variables must
be calculated to gain position. With 18 variables in total, the
understanding and calculation of each took longer than expected and would
not be completed by the deadline of second week lab session.
- Started work
through the entire calculation.
- Write a problem specification for the Arduino code, detailing the factors that needed to be considered and the sub problems they present, so the problem could be more easily explained on bench inspection day.
- Began
implementation of calculation in code.
Problems have arisen with calculation:
- Couldn't find the way to calculate ecliptic latitude (B) and longitude (L) of the Moon. The current solution to that problem is to take the data from the internet [1].
- Had troubles computing sidereal time at Greenwich.
Supervisor Meeting:
We discussed the difficulty of the calculation with Dr. Marsland
and explained that, this was why we were yet to show any finished project
deliverable's.
Notes and plans for week 3:
- Try to finish the whole Calculation.
- Research GPS and how it will be useful to the code
- Show
some finished project deliverables.
Friday 3 February 2017
Week 1
We researched the Arduino as a team to gain a better understanding of the physical module and its coding language.
- Received components:
- Raspberry pi camera
- Project plan:
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Week 1
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Week 2
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Week 3
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Week 4
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Week 5
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Week 6
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Testing
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Report
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Blog
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Moon Tracker software
specification
Problem
specification Team A:
Write a program to control a pan and tilt bracket,
allowing the following of the moon by a camera, mounted on top of said bracket.
Team B will then use the camera to take multiple pictures,
which will be overlaid via image processing to produce a detailed final image.
Analysis
Inputs:
·
Time of day when bracket is placed in position for
tracking
·
The date on which tracking is taking place
·
The longitude and latitude points of bracket position
Outputs:
·
Pan and tilt movement of the micro server controlled
bracket
Relevant
information for understanding of algorithm and astronomical terms:
Universal
Time - Also known as astronomical time or solar time, refers to
the earth rotation. It is used to compare the pace provided by international
atomic time with the actual length of an Earth day [1] .
Julian Day
number - is the integer number of days that have elapsed since the
initial epoch, which is defined as noon universal time, Monday, January 1, 4713
BC in the Julian calendar [2] .
Used to find celestial coordinate:
Right
Ascension – the representation of an observer points longitude on
earth in space [3] .
Declination
– the representation of an observer points latitude on earth in space [3] .
Used to find horizon coordinate:
Azimuth
Angle – The
azimuth (az) angle is the compass bearing, relative to true (geographic) north,
of a point on the horizon directly beneath an observed object [4] .
Altitude/Elevation - The elevation (el) angle, also called the altitude,
of an observed object is determined by first finding the compass bearing on the
horizon relative to true north, and then measuring the angle between that point
and the object, from the reference frame of the observer [4] .
Ecliptic
longitude and latitude – co-ordinates of the apparent path of the moon on the
celestial sphere.
Sidereal
time - Sidereal time measures the rotation of our planet relative to the
stars. It allows astronomers to keep time without worrying about the
motion of Earth around the sun [5] . Moon moves
around the earth in roughly 27.3 days, also known as 1 sidereal month, with its
average movement about 13.2 degrees per day [6] .
Further
considerations - Must take into consideration the speed of the earth(30 Km
per second), the speed that the moon is moving relative to the earth(3683 Km
per hour), also camera requires 10 seconds minimum between photographs.
[1] U. -. T. w. t. Standard, "timeanddate," [Online].
Available: https://www.timeanddate.com/time/aboututc.html.
[2] J. D. N. Fandom, "Fandom," [Online]. Available: http://calendars.wikia.com/wiki/Julian_day_number.
[3] A. MacRobert, "Sky and telescope," 20 July 2006. [Online]. Available: http://www.skyandtelescope.com/astronomy-resources/what-are-celestial-coordinates/.
[4] T. Target, "Azimuth and Elevation," [Online]. Available: http://whatis.techtarget.com/definition/azimuth-and-elevation.
[5] C. Crockett, "What is Sidereal time?," 10 June 2012. [Online]. Available: http://earthsky.org/astronomy-essentials/what-is-sidereal-time.
[6] M. Motion, "http://cseligman.com/text/sky/moonmotion.htm," [Online].
[2] J. D. N. Fandom, "Fandom," [Online]. Available: http://calendars.wikia.com/wiki/Julian_day_number.
[3] A. MacRobert, "Sky and telescope," 20 July 2006. [Online]. Available: http://www.skyandtelescope.com/astronomy-resources/what-are-celestial-coordinates/.
[4] T. Target, "Azimuth and Elevation," [Online]. Available: http://whatis.techtarget.com/definition/azimuth-and-elevation.
[5] C. Crockett, "What is Sidereal time?," 10 June 2012. [Online]. Available: http://earthsky.org/astronomy-essentials/what-is-sidereal-time.
[6] M. Motion, "http://cseligman.com/text/sky/moonmotion.htm," [Online].
Group Members:
Amy Bannon, Abdulrahman Alanazi, Dominyka Rubeziute,
Junkun Di and Yoka Zhang.
Supervisor:
Dr. John Marsland
Supervisor:
Dr. John Marsland
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