AutoLRPT

AutoLRPT is a small Bash script that allows you to receive LRPT images from Meteor M2-3 and Meteor M2-4 automatically by using mlrpt. The script only runs on Linux and can e. g. be used on a Raspberry Pi.

Dependencies

• mlrpt
  • Download mlrpt from 5B4AZ.com
  • Downlaod mlrpt from GitHub.com
• predict

Presupposed setup

You can follow the following instructions in case you are using a Raspberry Pi with Raspberry Pi OS. For other distros the setup should work similar but the names of the required packages might differ.

mlrpt

On the mentioned OS you first have to install a bunch of packages that are needed by mlrpt:

sudo apt install cmake make automake autoconf libtool rtl-sdr librtlsdr-dev

1. Download the latest package of mlrpt from 5b4az.org. The name of the package should be something like mlrpt-1.7.1.tar.bz2. You can do that from the commandline by running

wget http://5b4az.org/pkg/lrpt/mlrpt-1.7.1.tar.bz2

2. Unzip the package:

tar -jxvf mlrpt-1.7.1.tar.bz2

3. Now enter the folder of mlrpt and execute the following commands after another:

cd mlrpt-1.7.1

./autogen.sh
./configure
make
sudo make install

4. Enter the folder mlrpt, move the folder images and the config file default.cfg into previous directory and return to the previous directory:

cd mlrpt
mv images default.cfg ..
cd ..

5. Create two copies of default.cfg named M2-3.cfg and M2-4.cfg:

   scp default.cfg M2-3.cfg
   scp default.cfg M2-4.cfg
   

Open the two config files with your favourite editor and change the following settings:

Meteor M2-3

• Satellite Transmitter Frequency in kHz: 137100 to 137900
• Modulation Mode: 1 = QPSK 2 = DOQPSK 3 = IDOQPSK: 1 to 2

Meteor M2-4

• Satellite Transmitter Frequency in kHz: 137100
• Modulation Mode: 1 = QPSK 2 = DOQPSK 3 = IDOQPSK: 1 to 2

Unfortunately, mlrpt sometimes replaces the config file with one from /usr/share/mlrpt/examples/config. To avoid that you can delete the config files in /usr/share/mlrpt/examples/config and copy the config file ~/mlrpt/default.cfg to /usr/share/mlrpt/examples/config:

sudo rm /usr/local/share/mlrpt/examples/*.cfg
sudo scp /home/user/mlrpt/default.cfg /usr/local/share/mlrpt/examples/config

predict

For most distributions, predict is available in the official respositories. In case you can not find it there, you can also download it from here
On Raspberry Pi OS and other Debian/Ubuntu-based distros you can install it with the following command:

sudo apt install predict

Setup of AutoLRPT

Clone AutoLRPT into your home directory:

cd
git clone https://github.com/BaumGuard/AutoLRPT

Enter the folder of AutoLRPT:

cd AutoLRPT

Make the scripts executable:

chmod +x AutoLRPT_Meteor_M2-3 AutoLRPT_Meteor_M2-4 set_location TLE_Meteor_M2-3 TLE_Meteor_M2-4

Execute the script set_location and enter your name/callsign, latitude, longitude and altitude:

./set_location

Updating the TLE data

The so called TLE data is needed to calculate the position of a satellite at a given time and therefore also the pass times.

Meteor M2-3

The script TLE_Meteor_M2-3 downloads the current TLE data from CelesTrak.

You can choose whether the TLE should be updated automatically in regular intervals of 24 hours or if you want to update the TLE data manually. To update the TLE data in regular intervals, open the script and set the variable autoupd to 1.
Then execute the script:

./TLE_Meteor_M2-3 &

Meteor M2-4

The script TLE_Meteor_M2-4 downloads the current TLE data from CelesTrak.

You can choose whether the TLE should be updated automatically in regular intervals of 24 hours or if you want to update the TLE data manually. To update the TLE data in regular intervals, open the script and set the variable autoupd to 1.
Then execute the script:

./TLE_Meteor_M2-4 &

Paste the two lines you have copied below the satellite's name

Usage

Start AutoLRPT from inside its directory:

Meteor M2-3

./AutoLRPT_Meteor_M2-3 &

Meteor M2-4

./AutoLRPT_Meteor_M2-4 &

The & will execute the script in the background.

Now mlrpt should start automatially when Meteor M2 3 or Meteor M2-4 passes over. You don't need to start AutoLRPT again manually afer the pass, since AutoLRPT will automatically schedule the next pass.

Be sure to exit the console on which you have started AutoLRPT by running

exit

Otherways AutoLRPT will be stopped!

If you want to stop AutoLRPT

Meteor M2-3

killall AutoLRPT_Meteor_M2-3

Meteor M2-4

killall AutoLRPT_Meteor_M2-4

Additional options

You can change the following settings in AutoLRPT.cfg according to your needs:

• Minimum elevation
  Only record passes that have at least the given elevation.

  • Variable: min_elev
  • Possible values: 0 - 90

• Recording in the evening (Meteor M2-3)
  Due to a worse solar illumation by the sun, the images recorded in the evenings usually are rather dark and don't show that many details. You can choose whether you want AutoLRPT to record passes in the evenings or not

  • Variable: evening_rec
  • Possible values:
    • 0: Evening recording disabled
    • 1: Evening recording enabled

• Recording in the night (Meteor M2-4)
  Due to a worse solar illumation by the sun, the images recorded in the night usually are rather dark and don't show that many details. You can choose whether you want AutoLRPT to record passes in the evenings or not

  • Variable: night_rec
  • Possible values:
    • 0: Evening recording disabled
    • 1: Evening recording enabled

• Autoflip
  Because Meteor M2 3 and all the other LEO satellites will pass over from South to North in the evenings, the images will be upside down by default, but mlrpt can flip them. You can choose whether you want mlrpt to flip the images of evening passes automatically

  • Variable: autoflip
  • Possible values:
    • 0: Autoflip disabled
    • 1: Autoflip enabled

• Automatically update color channels
  Throughout the year Meteor M2 3 can change its color channels a few times. AutoLRPT can retrieve the currently active color channels from this webpage and adjust the color channels in mlrpt's default.cfg automatically. This will happen before every pass. You can choose whether you want AutoLRPT to update the color channels automatically or not

  • Variable: upd_channels
  • Possible values:
    • 0: Automatical update of color channels disabled
    • 1: Automatical update of color channels enabled

• Logging
  AutoLRPT can log information about the passes and the recording status in the file AutoLRPT.log
  
  The logs will have the folloing format:
  PassDate PassTime SatelliteName MaxElevation Azimuth Status
  Please note that the date and time are in UTC

  The Status gives some information about the success of the reception:

  • IMAGE_RECORDED: If an image was received and saved (successful execution of mlrpt)
  • NO_IMAGE_RECORDED: If no image was received (successful execution of mlrpt)
  • NO_RECORDING: If the user disabled the recording under certain circumstances (min_elev, evening_rec) - No exection of mlrpt
  • NO_SDR_CONNECTED: If mlrpt stops because no SDR was connected (unsuccessful execution of mlrpt)
  • ERROR: Any other errors

  You can choose whether you want AutoLRPT to log the passes or not:

  • Variable: logging
  • Possible values:
    • 0: Logging disabled
    • 1: Logging enabled