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
• 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

The repository of AutoLRPT contains a modified version of mlrpt. It adds an option in the config files to set the pattern of the file name, so that AutoLRPT-Slideshow can handle the image files better.

1. Move mlrpt.tar.gz to the home folder

   mv mlrpt.tar.gz ..
   cd

2. Unzip the package:

   tar -xzf mlrpt.tar.gz

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

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

Unfortunately, mlrpt sometimes replaces the config file with one from /usr/share/examples/mlrpt/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 -r /usr/local/share/examples/mlrpt
sudo scp /home/user/mlrpt/default.cfg /usr/local/share/examples/mlrpt/config

predict

For most distributions, predict is available in the official repositories. 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

If you can't install predict from the repositories you can also download it from here

wget https://www.qsl.net/kd2bd/predict-2.3.1.tar.gz

Unpack the tar.gz file

cd
tar -xzf predict-2.3.1.tar.gz
cd predict-2.3.1

Run the script configure

./configure

The script first checks for the existence of some libraries. If you haven't installed them already you can do so

sudo apt-get install libncurses5-dev libncursesw5-dev libasound2-dev

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_M2-3 AutoLRPT_M2-4 set_location tle_update

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.

The script tle_update downloads the current TLE data for Meteor-M2 3 and Meteor-M2 4 from CelesTrak and writes it to the file ~/.predict/predict.tle.

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_update

Usage

Start AutoLRPT from inside its directory:

Meteor M2-3

./AutoLRPT_M2-3 &

Meteor M2-4

./AutoLRPT_M2-4 &

The & will execute the script in the background.

Now mlrpt should start automatically when Meteor M2 3 or Meteor M2-4 passes over. You don't need to start AutoLRPT again manually after 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

Otherwise AutoLRPT will be stopped!

If you want to stop AutoLRPT

Meteor M2-3

killall AutoLRPT_M2-3

Meteor M2-4

killall AutoLRPT_M2-4

Start on boot

If you want to start AutoLRPT automatically after booting the Raspberry Pi, you can add a cronjob for both AutoLRPT scripts

Open the file /etc/crontab with your favorite text editor (in my case vim)

sudo vim /etc/crontab

Append these two lines on the bottom of the file

@reboot		<username>		<path-to-autolrpt>/AutoLRPT/AutoLRPT_M2-3
@reboot		<username>		<path-to-autolrpt>/AutoLRPT/AutoLRPT_M2-4

Using the command [sudo] crontab -e won't work!

Replace <username> with your user name and <path-to-autolrpt> with the path to the directory of AutoLRPT. This should be an absolute path!

Now both AutoLRPT scripts should start automatically after every boot.

Additional options

You can change the following settings in M2-3.conf and M2-4.conf 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 illumination by the sun, the images recorded in the evenings are usually 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 illumination 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

• Logging

  AutoLRPT can log information about the passes and the recording status in the file AutoLRPT.log

  The logs will have the following 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 execution 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