P20151: Satellite Localization

Problem Definition

Table of Contents

Team Vision for Problem Definition Phase

Our vision for the satellite localization problem definition began by thoroughly reviewing the previous project, P19151, to gain a better understanding of P20151’s current state. As a team, we carefully considered the scope of the project to make it well structured and achievable, as well as challenging in a way that motivates team members.



Project Summary

Since the year 2000, there have been approximately 291 CubeSat missions led by universities [1]. RIT SPEX has been working on developing their own CubeSat mission for the past 3 years, focusing on innovations in solar sail technology. Every satellite needs the means to operate and fly it and RIT does not currently have such a ground station. Last year, students began creating a ground station specifically for collecting NOAA downlinks (~144 MHz) for a specific class.

The scope of this project is to create a new ground station, LASSO (Localize Attribute SatelliteS in Orbit), capable of tracking and obtaining downlinks around the ~437 MHz band, one of the most common bands used by CubeSats. LASSO will utilize Time Difference of Arrival (TDOA) from multiple antennas to localize the source of a satellite signal, both reducing noise in data transmissions and enabling orbit determination. Orbit determination capability brings RIT one step closer to flying their own satellite. Commanding a large field of view of the sky, LASSO is able to categorize unknown signals after detection by comparing its own orbit calculation with the numerous public online catalogs. LASSO also enables new research and educational opportunities ranging from real data examples in classes for signal processing and orbital mechanics to collecting sensor data, collected from space objects.

LASSO uses TDOA for its mechanical simplicity and emphasis on software. Team members plan on utilizing open source and custom software to lower the project expenses. LASSO is the beginning of RIT’s ground station and new features are expected to be added by future MSD projects so that RIT is ready to run satellite operations when it sends its first CubeSat to space.

Use Case Scenarios

Use Case Scenario 1:

The main use for LASSO is to use it as a hands on learning tool for signals processing and astronomy classes.For example, a professor can use LASSO to collect data from NOAA satellites. This data can be used in a signals processing class activity to extract the weather map images from the satellite data. Astrodynamics classes could use LASSO’s TDoA to calculate satellite trajectories, or they could use LASSO’s calculated trajectories to perform orbit determination themselves.

Use Case Scenario 1

Use Case Scenario 1

Use Case Scenario 2:

The next use of LASSO is to use it to update and verify a satellite’s orbital parameters in a satellite catalog. Given the satellite’s frequency, LASSO will be able to detect the satellite and calculate its orbital parameters. This information can be updated in the satellite catalog to keep track of the growing number of satellites in the sky. When LASSO detects satellites, these satellites will be unknown to the LASSO operator. After determining the satellite’s orbital parameters, these parameters will have to be compared to a satellite catalog’s information to identify it.

Use Case Scenario 2

Use Case Scenario 2

Use Case Scenario 3:

A future use for the final version of LASSO is to be able to communicate with an RIT launched CubeSat. One of RIT SPEX’s ambitions is to launch a CubeSAT to collect data for research purposes. The LASSO system would provide the opportunity to have complete satellite communications (uplink and downlink) entirely run from the RIT campus. Project P20151 will lead the way by establishing a ground station with detection, localization, and downlink capabilities as a first step towards this goal.

Use Case Scenario 3

Use Case Scenario 3

Project Goals and Key Deliverables

The expected end result of this project is a ground station, capable of detecting, localizing, and attributing satellite signals in a given frequency band. The ground station can search the sky looking for interference or look for a specific satellite, given its orbital parameters. A focus is to make the system as reliable as possible, such that it can be used in a RIT classroom or in spacecraft operations consistently.
Key Deliverables
Functioning Ground Station Prototype
Functioning Antenna Prototypes
Orbit Determination UI
Signal Localization Demonstration
Orbital Determination/Attribution Demonstration
Documentation of all work on EDGE
User Manual
Update/Verify Orbital Parameters on a Satellite Catalog

Customer Requirements (Needs)

List of Customer Requirements

List of Customer Requirements

Requirements and Testing (Excel)

Engineering Requirements (Metrics & Specifications)

List of Engineering Requirements

List of Engineering Requirements

Requirements and Testing (Excel)


House of Quality

House of Quality

House of Quality

House Of Quality (Excel)

Design Review Materials

Problem Definition Review Documents:

Plans for next phase

By the end of the Systems Design Phase, we aim to have accomplished the following tasks:

Plan Outline

  1. Create a sponsorship/grant list
  2. Create a finished sponsorship request letter
  3. Meet with S.T.A.R. team lead for advice and lessons learned
  4. Decide on a systems level architecture
    • Confirm TDoA selection
      • Determine whether we have 3 roof access sites
      • Run a sensitivity test using omnidirectional antennas
      • Meet with RF expert for advise
      • Backup solutions in case TDoA is not feasible
    • Antenna
      • Confirm ~437MHz frequency selection
      • Narrow down specifications
    • Electronics
      • Determine housing dimensions and materials
      • Create systems level component list
    • Network connection among stations
      • Decide on connection method
  5. Create a preliminary BOM

To accomplish these goals, we have created individual plans for the next three weeks to help each of us to focus in on specific tasks and objectives.

Individual Three Week Plans:

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