GCOD – GMSPAZIO Constellation Optimization and Design

Thanks to the reduction of launch costs, the amount of satellites on orbit is growing quickly. New companies arise and develop new ways of using the space asset. This is mostly due to the design of new cheaper rocket launchers and to the satellites mass production. Therefore, the budget required for a launch is decreasing, allowing the space industries to invest more in the satellite itself. It is not a case if a lot of companies are deploying different kinds of mega-constellations. Moreover, the opening of the space asset to private companies leads to the implementation of less expensive projects, if compared to the previous national space projects.

Looking at this scenario, GMSPAZIO provides a tool dedicated to the study and optimization of satellite constellations. Existing applications are complex and general purpose driven, therefore adapting them to strict requirements needed for the design of a specific constellation is time consuming. Our tool, instead, is aimed to  solve this kind of problems offering an easy to use solution.


GCOD supports the developing phase of a project, thanks to its advanced algorithms. It searches for the optimal parameters that fit the operational constraints imposed by the user, such as the minimum number of satellites required to provide coverage to a location or a user defined area. The tool has different modules for different kind of constellation design related problems;  it can be used to search for optimal orbital parameters on a single plane or it can optimize an existing constellation, moreover it can aid in the design of  formation flying missions.

A satellite constellation is typically composed of several, structurally identical, satellites. If, for any valid reason, during the development of the satellite, a structural change must be introduced, the overall constellation performance will be affected. In this scenario our tool provides a fast feedback about the changes introduced.



GCOD is an application progressively updated and evolved. Release 1 is divided in two parts:


It searches the optimal orbital parameters for a single satellite in order to provide specific coverage;


Optimizes the constellation design starting from relevant mission requirements (e.g. satellites number minimization without affecting the overall performance).



  1. A&R Tool calculation purpose is to find optimal orbits for:
    • Coverage of one or more user defined areas of interest;
    • Coverage of one or more user defined ground stations given a minimum elevation angle constraint
  1. D&O Tool allows to choose among the most common mission requirements, and it is divided into two sections:
    • STANDARD DESIGN: constellation design based on a reference orbit, that can be defined using the A&R Tool;
    • OPTIMAL DESIGN: constellation design aimed to provide continuous coverage  given the line-of-sight (LOS) constraint.

The STANDARD DESIGN Tool allows the user to choose among three constellation design types:

  • USER DESIGN: for ground-tracks distance reduction or increase of observations frequency;
  • SOFTWARE DESIGN: to obtain the required maximum ground-tracks distance or precise revisit time value;
  • FORMATION FLYING: to obtain precise ground-tracks distance or revisit time value.


The OPTIMAL DESIGN Tool provides the user with functions useful to optimize specific types of constellations, such as:

  • Communications, with at least one (1-degree or more) satellite in LOS;
  • Multiple Coverage, with at least four (4-degree or more) satellites in LOS (e.g. a satellite navigation system).


The user can define the following mission approaches:

  • STREETS OF COVERAGE, for continuous, complete, 1-degree or multiple degree coverage of polar or non-polar constellations. All satellites and their relative orbital parameters will be provided, starting from minimum elevation angle constraint and coverage degree;
  • WALKER TRIPLETS, for continuous, complete, 1-degree or multiple degree coverage of Walker-type constellations. It will compute significant parameters for the constellation design, including:
    • Possible configurations and orbital parameters of each satellite, starting from Walker triplets;
    • Possible Walker triplets, coverage time and mean visible satellites number, starting from orbital parameters minimum elevation angle constraint and desired coverage degree.


The OPTIMAL DESIGN Tool  provides also an optimization function which, taking as input the values computed by the other available functions tries to maximize the continuous, worldwide or regional, n-degree coverage.

The capabilities to design and analyze a satellite constellation, makes GCOD an effective planning tool for any type of constellation development. This tool is suitable for every company involved in the constellation design such as communications companies; in this case, given the increase of data amount exchange, the tool allows optimizing considerably the total satellites number and, as consequence, the overall cost of a mission.

Project Description

Share this

GCOD allows users to design and optimize a walker constellation or a formation flying mission. Access to a specific area or to specific ground station(s) will be maximized, minimizing the number of required satellites.

Project Details

Date January 22, 2020
Categories Space

© 2016 GMSpazio s.r.l. All rights reserved.   Partita I.V.A.: 08473031006 | Cookie policy

Click Me