The research project is investigating the impact of different scheduling algorithms on CubeSat ground station performance.
There are three python programs we used to create a workflow that simulated ground station scheduling:
reservation_generation.py: Generates random ground station reservations simulating a CubeSat in polar orbit.scheduler.py: Takes the ground station reservations, uses a scheduling algorithm to resolve the conflicts, and writes a master schedule.analysis.py: Performs statistical analysis on the generated schedule to evaluate algorithm effectiveness. Ex: Ground station time per mission, percent mission won in a conflict, and so on.
The reservation_generation.py file generates a json file that shows when each satellite would like to be scheduled at a given ground station, without respect to conflicts. This is approximated by two back to back passes, then a twelve hour delay to the next set of back to back passes.
Parameters:
- Missions: Satellites to generate a schedule for, followed by the offset to their first pass.
CP7:50,CP12:90includes two satellite in the reservations, one which is offset 50 minutes and one which is offset 90 minutes. - Ground Stations: The Ground Stations used to operate these missions and their offset from 0.
hertz:0,purdue:180includes two stations, one of which is offset 180 minutes. - Length: Amount of time in minutes to run simulation for.
Example Run: python3 reservation_generator.py -m CP7:50,CP12:90 -g hertz:0,purdue:180 -l 18000 reservation.json
The scheduler.py file generates a master schedule for all the satellites at each ground station taking into account conflicts. The master schedule is generated in the form of a json file. Each school will have its own master schedule.
Parameters:
- Ground Stations: A list of ground stations that a given school has.
- Length: How many minutes long to generate a schedule for.
- Algorithm: The algorithm that is going to be used to resolve conflicts.
- Priority List: (optional) The priority list of satellites, required for some algorithms.
- Reservations: The reservation file to be used to make a schedule.
- Schedules: The resulting json file that contains the master schedule.
Example Run: python3 scheduler.py -g hertz -l 30 -a plist -pl CP7,CP12 testreservations.json schedules.json
The analysis.py file is used to create an html file that has a graph containing statistics on how much each satellite is used at a given ground station and how conflicts are settled.
Parameters:
- Schedule: The json file that contains the master schedule generated from scheduler.py
- Chart: The name of the chart file that will be generated.
Example Run: python3 analysis.py scheduler.json chart.html