.:.


RADIO


one scientist's noise is another scientist's data


TABLE OF CONTENTS




RECIEVE NOAA WEATHER IMAGES


2019 05 26

pretty happy that this worked, even if it's so fuzzy
it was cloudy and i held the antenna with my hand
--radio tower is on backburner for now
--new photos when life permits
--will take notes next time and give some steps






2020 01 04

picked it back up and not sure what i am forgetting

instead of trees being in the way i am in town, with antenna on the roof
flat topped building, low flat area
there's a usb extenstion cord i didn't use last time either

fail 1 - my computer's mic mute button was on, so all input was disabled


fail 2 - strange patterns? 


fail 3 - still same patterns?


fail 4 - reduced sample rate from 2.4 to 1.0 MSPS , now new strange pattern?


if this is interference why am i only getting the patterns while i have a signal?

2020 01 05


i had set the cable to listen to itself instead of output to the speaker by mistake
now that's gone it's looking better. had a few good passes today
very windy and cloudy and night for all these, not sure how much that changes things

same equipment as before and antenna still on apartment roof







2020 01 20


i had 20 minutes till noaa 18 flew over and rushed a hunk of metal onto the roof 
to see if grounding the tram 1185 would clean things up.

also was snowing, and made me cut corners. could have been closer to the center of roof

this time i used the record function built into SDR# and imported the audio to NOAA-APT

this program is a lot simpler and faster than wxtoimg, but does not seem to have the live processing

i am not sure what else to do with this program but i am impressed with how simple it is.

i might still need wxtoimg to try and get the land outline overlaid and include false colour/

anyway, was a test, will probably continue using wxtoimg for auto downloads until i understand more



this is a with "no sync" selected. 
i believe the shape of this file can tell me a bunch that the synced version can't. 
but i can't read static yet ha



rough outline of WXTOIMG procedure

HARDWARE:
ANTENNA TRAM 1185
ANTENNA CABLES
ADAPTOR ANT. TO MCX MALE
RTLSDR DONGLE PICK ONE OF THESE
USB EXTENSION COR
WINDOWS LAPTOP

STEPS:

DOWNLOAD AND INSTALL:

A. SDR program - SDR#

B. weather satellite image processing software - WXTOIMG

C. virtual audio cable - VB VIRTUAL AUDIO CABLE

RUN A - OUTPUT TO C

TUNE A TO SATELITTE FREQ

RUN B - INPUT FROM C

SET B TO AUTOPROCESS/RECORD AND CREATE IMAGES

OTHER SOURCES:
https://www.planetary.org/blogs/jason-davis/2015/20150921-how-to-download-weather.html

https://www.rtl-sdr.com/receiving-noaa-weather-satellite-images/

rough outline of NOAA-APT procedure

HARDWARE:
ANTENNA TRAM 1185
ANTENNA CABLES
ADAPTOR ANT. TO MCX MALE
RTLSDR DONGLE PICK ONE OF THESE
USB EXTENSION COR
WINDOWS LAPTOP

STEPS:

DOWNLOAD AND INSTALL:

A. SDR program - SDR#

B. weather satellite image processing software - NOAA-APT

RUN A - TUNE TO SATELITTE FREQ (WHEN SATELLITE OVERHEAD)

RECORD WAV AUDIO OF SIGNAL USING SDR#

RUN B - PROCESS WAV FILE

OTHER SOURCES:
https://noaa-apt.mbernardi.com.ar/










RESOURCES



















SATELLITES


NOAA

NOAA 15 
NOAA 17 RETIRED
NOAA 18 APT 137.9125MHZ
NOAA 19 APT 137.1000MHZ / 1698.000S

rtl-sdr noaa tutorial
antenna > RTL-SDR > RPI/laptop > SDR#/other? > WXtoIMG

LIGHTSAIL

LIGHTSAIL 1 OFFLINE

LIGHTSAIL 2 / PROX WM9XPA 437.025MHz AX.25 FSK 9600bps

mission control @ planetary.org


TRANSMITTERS


FM - TETSUO MICRO


tetsuo kogawa's simplest microtranmitter

tetsuo kogawa radio art
https://www.youtube.com/embed/gn8B-L2CMso
https://www.youtube.com/embed/2MZEUKQxANI


SDR



SDR - software defined radio

sdr takes advantage of computers by using software
to do the tasks of signal processing usually done by hardware
(which are expensive or hard to build)

an antenna is connected to an SDR device that
converts the analog rf signal into a digital signal
where the computer takes over

    Y
    |
    |[antenna]
    |
    |
    I_________[sdr]____[computer] > [software]


RTL-SDR


rtl-sdr.com

RTL-SDR refers to the RTL2832U chip found inside of a cheap
DVB-T USB dongle (digital video broadcasting - terrestrial)
originally meant to carry TV signals, RTLSDR drivers
can be modified to be a general purpose SDR device

it's a cheap sdr device


RTL-SDR DRIVERS FOR WINDOWS



like most USB devices
you just plug the rtl-sdr into your windows computer
and it figures itself out and it just works.
but we aren't using the rtl-sdr as it was intended

a little program called zadig will replace
the packaged driver with a modified version

zadzig website
rtlsdr.com zadzig tutorial


STREAM RTL-SDR FROM R.PI



note i got this to work but it crashes due to power, so a powered hub is key
from: photobyte.org
Using the Raspberry Pi as an RTL-SDR dongle Server
Written by: Mike Richards G4WNC
3-4 minutes

Installing RTL SDR Software

NB: UPDATED 20 July 2018
Added copy command
1. for udev rules
2. Amended required packages to include git and libusb-1.0.0-dev


Manual Installation

The first step is to install a few packages
that are required by the RTL-SDR server.
You may already have some of these so don’t worry if 
you see a message that you already have the latest version.

To install these packages, 
type the following at the LXTerminal command line.

sudo apt-get install -y git cmake pkg-config libusb-1.0-0-dev
Now you can download the RTL-SDR code from osmocom by typing the following at the commandline:
git clone git://git.osmocom.org/rtl-sdr.git
The next step is to build RTL-SDR using the following commands. NB: Some of these may take a while so it’s probably time for a beer!
1. cd rtl-sdr 2. mkdir build 3. cd build 4. cmake ../ -DINSTALL_UDEV_RULES=ON 5. make 6. sudo make install 7. sudo cp ../rtl-sdr.rules /etc/udev/rules.d/ 8. sudo ldconfig
Blacklist the DVB-T Drivers The later versions of Raspbian include standard drivers so that the Dongles can operate in their original role as a USB Radio/TV device Unfortunately, these drivers prevent access to the dongle by the rtl-sdr software. The solution is to create a dedicated blacklist file to prevent the unwanted drivers from loading. Here’s the process: From the command line enter the following:
sudo nano /etc/modprobe.d/blacklist-rtl.conf
This creates a new file so enter the following lines:
blacklist dvb_usb_rtl28xxu blacklist rtl2832 blacklist rtl2830
Press control-X followed by Y to exit and save the modified file. Now reboot the Pi:
sudo reboot
That completes the build and you can run a quick test by making sure your dongle is connected and typing:
rtl_test -t
To start the server you need to access the Pi command line and type: rtl_tcp -a ‘your Pi’s IP address’. As a practical example, the start command for my setup is:
rtl_tcp -a 192.168.1.100
Auto Boot It is very easy to configure the Pi to automatically run the SDR server when it powers-up. This is done by modifying the rc.local file that automatically runs on boot. We need to include two new lines in the file. The first delays execution for 10 seconds whilst the network starts and the second runs the command to start the server. The delay is necessary because the new Jessie release runs rc.local before the network is up so we won’t have the vital IP address. To open the rc.local file for editing type:
sudo nano /etc/rc.local
update the content of rc.local as follows:
sleep 10 _IP=$(hostname -I) || true if [“$_IP”]; then printf”My IP address is %s\n” “$_IP” /usr/local/bin/rtl_tcp -a $_IP & fi exit 0
Type control X followed by Y and Enter to save the changes. That’s it – you should have an RTL-Server that auto-boots. I don’t recommend using a Wi-Fi dongle but if you do you will need to increase the sleep time as the network setup will take longer. Good Luck, Mike – G4WNC