It guides on how to download weather images from NOAA Satellites using SDR and QFH antenna

1. DOWNLOAD NOAA SATELLITE IMAGES WITH SDR
KU Robotics Club
www.ku.edu.np/kurc
Jiten Thapa (9N1JT)
jitenthapa56@gmail.com

2. WHAT IS SDR?
-software defined radio
-a radio is any device that transmits or receives information wirelessly through
the use of electromagnetic waves known as radio waves
-Software-defined radios must be able to change the physical functionality of the
radio through software

3. ADVANTAGES OF SDR
-SDRs is that they could be cheaper than dedicated hardware radios in some respects
-ease of testing and implementation of communication standards

4. SDR RECEIVER
Wide band antenna: to capture large bandwidth
BPF is used to help extract the desired signal by filtering out unwanted frequency bands.
The LNA amplifies the very low power signal captured from the antennae, so that it can be
processed more easily into a digital signal
Mixer takes the high frequency received signal down to a lower, more manageable frequency
through a process called demodulation
This band-pass filter blocks all frequencies outside of the signal’s new intermediate
frequency.
The ADC converts the transmitted analog signal into a digital signal, a process known as
sampling and quantizing.

5. SDR TRANSMITTER

6. SAMPLING AND QUANNTIZING

7. BAND PASS FILTERING

8. SDR HARDWARE- UNIVERSAL SOFTWARE RADIO PERIPHERAL
One of the most popular SDR front-end hardware
modules
versatility, large development community, and high
amount of associated software
consists of an antenna connected to an radio frequency
(RF) front end, analog to digital converter (ADC), digital
to analog converter (DAC), and a field programmable
gate array (FPGA)

9. FLEXRADIO SYSTEMS
one of the most
popular SDR units for amateur,
home, and personal use.

10. FUNCUBE DONGLE
FUNcube Dongle is a low-cost, SDR
receiver primarily
created for educational and
amateur purposes. Consisting of a
very small USB dongle,
the FUNcube allows users access to
a limited frequency band between
150 kHz and 1.9
GHz

11. DOWNLOAD IMAGES FROM NOAA SATELLITE
What do we need?
1. RTL SDR USB dongle
2. Antenna of 137 Mhz
frequency
3. SDRSharp
4. Wxtolmg

12. ANTENNA
QFA Antenna
Constructed by PVC Pipes and coaxial cable.
Low gain
Circularly polarized antenna
Advantages: no need of tracking like a Yagi Uda antenna
Construction: here

13. NOAA SATELLITES
The NOAA satellites only pass overhead at certain times of the day, broadcasting a
signal. These signals appear at around ~137 MHz, and only when a satellite is
passing overhead. Each satellite has a different frequency. Currently only NOAA
satellites 15, 18 and 19 are operational, their frequencies are shown below.
NOAA 15 – 137.6200 MHz
NOAA 18 – 137.9125 MHz
NOAA 19 – 137.1000 MHz

14. GETTING STARTED
Download Wxtoimg : http://www.wxtoimg.com/
Download SDRSharp.
Download VB Audio Virtual

15. WXTOIMG- SET LOCATION
Open WxtoImg
Go to Options- Ground station location
And enter the city and country in this case
Kathmandu and Nepal

16. WXTOIMG- RECORDING OPTIONS
Go to Options- recording options
Select soundcard as VB Audio Virtual. If
you don’t have one you download it.

17. WXTOIMG- UPDATE KEPLERS LOCATION
The path of the satellite can change due to various reasons. So you
need to update Keplers location once in a while.

18. WXTOIMG- PATH LIST
File-> Satellite Path List
This gives prediction when the
NOAA Satelltie passes through the
given place.
Then you need to test the antenna at
the time shown in the pass list.
Be ready about 10 minutes before.

19. SDRSHARP
Open SDRSharp and tune it to frequency of 137Mhz.
Connect the SDR to the USB and connect the antenna to the SDR.
When the satellite passes above you, you can hear a nice sound like the sound
generated by a 555 time with 2 Hz frequency.
Before the satellite comes above you, you need to record the decoding.

20. WXTOIMG- RECORD
File->Record, and click on Auto Record. The
recording and decoding will begin when the
satellite appears on your horizon, and stop
when it goes out of view according to the
times in the satellite pass list.

21. SET UP SDRSHARP
Open SDRSharp.
Chage the frequency to 137 Mhz
In the audio tab, select VB Audio
Vitual C

22. STEPS TO GET NOAA IMAGES
Open WxtoImg.
Update Keplers
Satellite path list
Select the suitable time for you and make everything ready before 10 minutes.
Put the antenna in a open space, if there are clouds good quality of image cant be received.
Set up the antenna, connect to SDR and plug in the SDR in USB.
Open SDRSharp.
Chage the frequency to 137 Mhz
In the audio tab, select VB Audio Vitual C
In WxtoImg, File->Record, and click on Auto Record
Then the software starts to decode the image and show the image on the screen.

23. SOME IMAGES THAT WE RECEIVED

24. THANK YOU