New features:

• The calculation of the orbital parameters is now faster because the perifocal velocity is not calculated.

Bug fixes:

• Fixed the memory leak caused when plotting the satellites' coverage by updating Cartopy.
• Dropped support for Cartopy 0.17.0.
• Fixed a bug in which the background image was not updated when the time moved backward.

New features:

• Added interactive buttons into the status bar for some already implemented functions like adding or removing satellites, adding or removing the satellite's coverage, deployment simulation, among others.
• Changed some button's text into icons.
• Added a navigation toolbar from matplotlib. Now it is polsible to zoom to a rectangle and pan the image.
• Thanks to the navigation toolbar, the cursor's coordinates in latitude and longitude are displayed in the status bar.
• Removed some buttons for changing the time manually since the QDateTimeEdit widget has that functionality.
• Added buttons to forward, backward, pause, and resume time.
• Replaced the segmented line for the trajectory with a continuous one.
• Added a setup.py and a .desktop file to improve Pypredict's installation procedure. Now it can be installed using pip. The dependencies are much more clear and it is easier to use.
• Added more documentation.

Bug fixes:

• Fixed a bug in which the day and night pictures were continuously being opened and closed. Now they are only opened once, which translated into a huge performance boost.
• Fixed a memory leak problem related to the beforementioned bug.
• Fixed a bug introduced in the last release in which the satellites' names were interchanged after a deployment simulation.

New features:

• The program is now using QT instead of TK.
• The world map and the table are now displayed in two different tabs. Each table is only updated when the user is watching it, improving performance.
• The user can change the date or the time with the mouse wheel on a QDateTimeEdit widget.
• The table can be sorted by any column (latitude, longitude, altitude, etc.).
• All the satellites use the SGP4 orbit propagator.
• Now the user can add his own txt. file with TLE data into this program.
• The user can save the TLEs of the current satellites into a txt. file.
• It is now possible to save a picture of the map without white borders.
• Improved general responsiveness of Pypredic.
• Now the satellite's positions, the background image, and the table data are updated more frequently without sacrificing performance.
• Added zoom in and zoom out capabilities with the mouse wheel.
• Added the South Atlantic Anomaly (SAA).
• Some basic data can be sent into a Pymongo database.
• When the user updates the TLE data from the internet, a QDialog is opened which shows the files that are being downloaded and a progress bar.

Bug fixes:

• Fixed a bug in which the coverage of a satellite filled the whole image because a portion of fewer than three points prevented from creating a polygon.
• Fixed a bug in which the background image was updated every time the QDateTimeEdit widget was updated.
• Fixed a bug that created a time lag in the program's data because of a signal that was triggered when the QDateTimeEdit widget was updated.

New features and bug fixes:

• The background composite image (day/night) is now updated every 4 minutes.
• The background image now does not have white pixels between the day and the night side of the map.
• The animation restarts every 4 minutes, so now if it get stuck, it will fix itself.
• Added a help menu which displays the program's version and contact information.
• Removed some unused functions.
• Fixed error in TDOA (but it still needs further improvement).
• More minor changes.

The deployment popup now allows the user to input the deployed satellite's name, category, mass, the deployer's mass and the velocity of deployment in the 3 axis wit respect to the deployer's orbital frame. The background image of the deployment and localization button has change to match the Pypredict's theme.

All the satellite's now update their orbital parameters considering the drag effect of the atmospheric density.

Added the images for the simulation buttons.

This new version has the feature of using a composed image of the Earth at night and at day from NASA instead of just plotting a semi-transparent day/night terminator. It is still possible to use the old day/night plot, because the background does not have the ability to update after certain amount of time yet.

It is also possible to simulate a satellite deployment from a CubeSat using the "Simulate deployment" button. Now the table below displays the satellites' speed and their category type.

I recommend using Matplotlib's version 2.1.1, because I had issues with the latest version. If you still want to use Matplotlib 3.x.x, then I suggest to install libtcmalloc-minimal4 to avoid an error. To do this, you have to do the following:

sudo apt-get install libtcmalloc-minimal4
export LD_PRELOAD="/usr/lib/x86_64-linux-gnu/libtcmalloc_minimal.so.4.3.0"