1. 2012 /13 Monmouth Science Imitative Project
11Ghz Small Radio Telescope
Electronics developed during 2012
Commercial satellite TV equipment modified
Measurements made in 2013

2. Post detector amplifier Digitiser Lap top computer
Main component are:
1.2m dish
Low noise receiver
Detector unit
Post detector amplifier
Digitiser
Lap top computer
Detector
Post detector
amplifier
Digitiser
Low Noise
Receiver
1.2m diameter offset
Parabolic dish

3. Students built and tested the post detector electronics
It provides signal offset
Amplification
Filtering

4. Data is generated by driving the antenna in azimuth and recording
the digitised received signal
The dish elevation is raised and the scan repeated
This produces a two dimensional array of numbers
False colour images can be generated from this data
All hot bodies (ie T > 00 K) emit radiation
This extends into microwave region
The ground is ‘hot’ at microwave
frequencies
This can be measured with the
sensitive 11GHz ‘Radiometer’
Signal level from hot bodies is greatest
toward optical frequencies
Plank’s Law
microwaves

5. 11GHz Radio Data Map 13/11/2013 Values represent intensity of
Elevation Angle
Elevation Angle
11GHz Radio
Data Map 13/11/2013
Azimuth Bearing
Azimuth Bearing
Values represent
intensity of
received signal

6. The first step of data reduction is to plot each azimuth scan
This can be done in EXCEL
Shows some large spikes
These are satellites
Also shows ground features
Excel Plot of 11GHz Azimuth Scans for different Elevations –
Monmouth School 13/11/2013
Signal Intensity (Volts)
150E
120E 00
100
Azimuth Bearing
90E
200
Elevation Angle
300
60E
400
30E
500 S
30W

7. Excel Plot of 11GHz Azimuth Scans for different Elevations - Monmouth School 13/11/2013
European
Satellites
Building
Signal Intensity (Volts)
High
Ground
Ground
temperature
Building
Atlantic Satellites 00
100
30W S
30E
60E
90E
120E
150E
200
300
Azimuth Bearing
Elevation Angle
400
500

8. The 2D data map can be converted to a visual image
Used ‘Stanford Chart’ software
Shows ‘cold’ blue sky
‘Hot’ satellites
Ground temperature

9. Radio image of Sky at 11 GHz
11GHz Radio Map of Sky South of Monmouth 13/11/2013
500
‘Cold Sky’
450
400
Atlantic Satellites
350
European Satellites
300
250
Elevation
200
Satellite
Building
Building
100
High Ground
150 50 00
Time 15:35hrs GMT, Dish No 1, Automatic Azimuth Drive, 50 elevation steps,ADC11 Data Logger, Stanford Chart Mapping
150E
140E
130E
120E
110E
100E
90E
80E
70E
60E
50E
40E
30E
20E
10E S
10W
20W
30W
Azimuth Bearing

10. Graphic showing area scanned by antenna
SOUTH
EAST
WEST
Sector Scanned
Satellites(200E)
High Ground (900E)
Map of Test Location showing Key Features of Radio Map
Antenna Site

11. The measurements were repeated with the system sensitivity at maximum
Similar features
More detail in the sky
Can see water vapour
concentration in clouds over
high ground

12. More sky temperature detail can be seen

13. Map with no colour blending – shows maximum effect

14. A second series of measurements was undertaken
Aim was to map the SUN
Equipment moved onto the ‘Green’ for southerly view
Unfortunately the SUN was below the building line
It was obscured and no SUN image was obtained
Experiment to be repeated in summer time

15. Building obscured views in most directions Some gaps between buildings
Location of
Antenna
Hemisphere
scanned
North
Location of Antenna
satellites

16. A composite picture of the buildings was created
This was used to make building outlines
These outlines were applied to the radio image
Able to identify some building features

17. Radio image of sky and buildings
Shows satellites and unidentified signals
Can see some details of buildings
45 0
Satellites
SUN was
behind building
here
Unknown signal
sources
Can see radio emission
from chimneys
Elevation to 450
0 0
0 0
Azimuth
20 0 East of South
South
West
North West

18. The project has shown that it is possible for students to construct
a small 11GHz radio telescope
Use to map the sky and show the ‘ arc’ of geostationary satellites
Discover that the ground, buildings etc emit microwave radiation
Record and analyse large data sets
Make false colour images with software
Understand some of the techniques used in Radio Astronomy