Zimbabwe GNSS Ionospheric Information System (ZGIIS)

Source of truth: kuhamba-tech/zingsa-tec-analysis (master).

ZGIIS consists of a Next.js frontend and a FastAPI backend. The legacy Streamlit interface has been removed.

This Python app replaces MATLAB post-processing and follows the same operational flow used with GOP:

1. Process RINEX in GOP to create .Cmn files.
2. Load .Cmn files in this app.
3. Filter noisy observations with elevation mask >= 25 deg.
4. Extract and analyze Time, Elevation, VTEC.
5. Produce day, month, and year TEC summaries with storm visualization.
6. Optionally merge Kp index to study TEC-Kp relationship.

Theory (Chapter 4 aligned)

From Atmospheric Remote Sensing - Chapter 4 (Gopi K. Seemala):

• Slant TEC is computed from dual-frequency GNSS observables (L1/L2 or P1/P2 forms).
• Vertical conversion is done using a single-shell ionosphere model at IPP height (default 350 km).
• Mapping form used in code:
  • M(E) = 1 / sqrt(1 - (Re*cos(E)/(Re+h))^2)
  • VTEC = STEC / M(E)

Depending on notation, this is equivalent to VTEC = STEC * S(E) when S(E)=1/M(E).

Run locally

python3.12 -m venv .venv
.venv/bin/python -m pip install -r backend/requirements.txt
.venv/bin/uvicorn backend.main:app --host 127.0.0.1 --port 8000

In a second terminal:

cd frontend
npm install
npm run dev

Open http://localhost:3000. The API is available at http://localhost:8000, with interactive documentation at http://localhost:8000/docs.

For the Zimbabwe North–South TEC research module (Live Space Weather → Zimbabwe tab):

http://127.0.0.1:3001/space-weather/?tab=zimbabwe

API: GET /live/north-south-tec-research?hours=24&resample_minutes=15

On Windows, run.ps1/dev.ps1 starts both services.

Supabase database

Supabase is the recommended hosted Postgres replacement for the live ZGIIS app. Use it for CORS station status, TEC measurements, TEC map metadata, ionosonde comparisons, alerts, users/permissions, reports, and receiver-bias history.

Set the hosted database URL in .env or your deployment environment:

SUPABASE_DATABASE_URL=postgresql://postgres:[PASSWORD]@[SUPABASE_HOST]:5432/postgres

SUPABASE_DATABASE_URL is the only database setting. Long-running processes use that session-pooler URL. Vercel functions use SUPABASE_POOLER_URL. The self-hosted pooler has no TLS, so the app sets sslmode=disable unless the URL already chooses a mode.

To bootstrap the tables:

python scripts/init_supabase_schema.py

If SUPABASE_DATABASE_URL is missing, database routes return HTTP 503.

One-click Windows launcher

Use PowerShell:

cd "C:\Users\Tapiwa\Documents\Timothy\ZINGSA\Space Science\tec_python_app"
.\run_app.ps1

Optional custom port:

.\run_app.ps1 -Port 8502

Recommended input folder

Use your processed folder, for example:

C:\Users\Tapiwa\Documents\Timothy\ZINGSA\Space Science\TEC ANAlYSIS

The app recursively reads all .Cmn files.

Outputs

Saved in <data_folder>\tec_python_outputs:

• filtered_observations.csv (time/elevation/vtec records after >=25 deg filter)
• daily_summary.csv
• monthly_summary.csv
• yearly_summary.csv

KP CSV format (optional)

Provide a CSV with at least:

• date (or day / timestamp)
• kp_index (or kp / kpindex)