SCOPTSCOPT Inc.
Simulation software

HSCT — HAPS-to-Satellite Communication Simulator

The HAPS–Satellite Communication Tool (HSCT) is a Windows-based standalone application for designing and analysing communication links between a High-Altitude Platform Station (HAP

Overview

The HAPS–Satellite Communication Tool (HSCT) is a Windows-based standalone application for designing and analysing communication links between a High-Altitude Platform Station (HAPS) in the stratosphere (15–30 km) and an orbiting satellite in LEO, MEO, or GEO. It models both the free-space optical (FSO) and radio-frequency (RF) channels, in uplink or downlink, and computes average BER, ergodic capacity, outage probability, and a full link budget with availability fade margins through a Monte Carlo engine. Every geometric quantity is derived from exact spherical-Earth relations - the flat-Earth approximation is wrong by over 5× at GEO/low elevation. Distributed as a self-contained executable.

Key features

  • Spherical-Earth link geometry and orbital mechanics — exact slant range, elevation, angles for LEO/MEO/GEO and a 15–30 km HAPS; orbital velocity and period; Doppler; optical point-ahead; live Derived-Geometry readout.
  • Free-space optical (FSO) channel — beam-wave scintillation (validated to 0.1–0.9% vs the textbook's GEO examples); six irradiance-fading models; layered Beer–Lambert attenuation with cloud/volcanic layers; pointing, point-ahead, and AoA error; day/night background radiance.
  • Radio-frequency (RF) channel — Shadowed-Rician / Rician / Nakagami-m fading; full ITU-R stack (FSPL, rain, gas, cloud); ionospheric scintillation and Faraday rotation; direction-dependent noise temperature.
  • Performance metrics and simulation engine — BER, Outage, Ergodic Capacity, decomposed Link Budget with 99%/99.9% fade margins; Monte Carlo engine with resolution warnings and no hidden smoothing.
  • Realistic multi-orbit comparison — overlay LEO/MEO/GEO (or up/down) with each curve placed by its true link-budget disadvantage; model-applicability warnings.
  • Validated and fully documented — 48-check validation package against closed forms, textbook examples, and ITU-R data; every formula source-traced.

Use cases

  • Satellite Communications Industry: Link analysis, feasibility, and fade-margin sizing for HAPS-relay and HAPS-backhaul architectures across LEO, MEO, and GEO, in both optical and RF bands
  • Aerospace System Designers: Planning of resilient inter-platform links - sizing optical apertures, beam divergence, transmit power, antenna gains, and pointing/point-ahead budgets, including the uplink/downlink asymmetry
  • Academic Research & Education: A validated, source-traceable platform for teaching and studying stratospheric-to-space propagation, turbulence, fading, and ionospheric effects, with every model openly documented
  • Availability & Weather-Resilient Design: Impact evaluation of elevation, orbit choice, cloud and volcanic-aerosol layers, and ionospheric conditions on link availability and required margin

System requirements

  • Operating System: Windows 10 / 11 (64-bit)
  • Software Dependencies: None - no MATLAB, no MATLAB Runtime (MCR), and no Python required. The tool is a fully self-contained compiled executable; everything it needs is bundled in the installer.
  • Memory: 4 GB RAM minimum (8 GB recommended for large Monte-Carlo runs)
  • Disk Space: ~250 MB
  • Connectivity: None required to run - the simulator works entirely offline (a one-time online activation applies to the licensed and demo editions)
HSCT — HAPS-to-Satellite Communication Simulator · SCOPT Inc.