GEOS Xray Plot Setup

UKSMG Desktop – GOES X-Ray Daily Plot

The UKSMG Desktop page displays a GEOS/GOES X-Ray Daily plot in one of its iframe windows. The original data source is: https://www.swpc.noaa.gov/products/goes-x-ray-flux .

In 2025, NOAA stopped providing static images for X-ray data, which caused the original UKSMG Desktop display to break. To resolve this, a Python script was created to retrieve raw NOAA data and regenerate the plot dynamically.

After migrating to a new VPS provider, Python 3 was not installed, so the following setup steps were required.

System Setup

Run the following commands as root:

<code>mkdir ~/goes-project
cd ~/goes-project</code>

Update package lists

<code>sudo apt update</code>

Install Python and dependencies

<code>sudo apt install -y python3-pip python3-venv python3-dev</code>

Verify pip installation

<code>pip3 --version</code>

Expected output:

<code>pip 23.x from /usr/lib/python3/dist-packages/pip (python 3.x)</code>

Create a virtual environment

<code>mkdir -p ~/venvs
python3 -m venv ~/venvs/goes
source ~/venvs/goes/bin/activate</code>

Your prompt should change to:

<code>(goes) user@server:~$</code>

Install Python packages

<code>pip install --upgrade pip
pip install pandas matplotlib requests</code>

Verify installation

<code>python -c "import pandas, matplotlib, requests; print('OK')"</code>

Expected output:

<code>OK</code>

Python Script

Create the following script:

<code>#!/usr/bin/env python3

import requests
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
from datetime import datetime, UTC

URL = "https://services.swpc.noaa.gov/json/goes/primary/xrays-1-day.json"

OUTPUT = "/var/www/vhosts/uksmg.org.uk/httpdocs/images/goes_xray_daily.png"

# -----------------------
# Load data
# -----------------------
data = requests.get(URL, timeout=30).json()
df = pd.DataFrame(data)

df = df[df["energy"] == "0.1-0.8nm"].copy()
df["time_tag"] = pd.to_datetime(df["time_tag"])
df["flux"] = pd.to_numeric(df["flux"], errors="coerce")
df = df.dropna()

# -----------------------
# NOAA-style figure
# -----------------------
fig, ax = plt.subplots(figsize=(12, 5), facecolor="white")
ax.set_facecolor("white")

ax.semilogy(
    df["time_tag"],
    df["flux"],
    color="#1f4e79",
    linewidth=1.2
)

ax.set_title(
    "GOES X-ray Flux (0.1–0.8 nm)",
    fontsize=13,
    fontweight="bold"
)

ax.set_xlabel("Time (UTC)", fontsize=10)
ax.set_ylabel("Watts m⁻²", fontsize=10)

ax.set_ylim(1e-9, 1e-2)

ax.grid(True, which="both", linestyle="-", linewidth=0.3, alpha=0.25)

ax.xaxis.set_major_formatter(mdates.DateFormatter("%H:%M"))
plt.xticks(rotation=0)

# Flare thresholds
flare_levels = [
    (1e-7, "A"),
    (1e-6, "B"),
    (1e-5, "C"),
    (1e-4, "M"),
    (1e-3, "X"),
]

xpos = df["time_tag"].max()

for level, label in flare_levels:
    ax.axhline(level, color="grey", linestyle="--", linewidth=0.6, alpha=0.4)
    ax.text(
        xpos,
        level,
        f" {label}",
        va="center",
        ha="left",
        fontsize=9,
        color="black"
    )

ax.spines["top"].set_visible(False)
ax.spines["right"].set_visible(False)

updated = datetime.now(UTC).strftime("%Y-%m-%d %H:%M UTC")

plt.figtext(
    0.99,
    0.01,
    f"Updated: {updated}",
    ha="right",
    fontsize=8,
    color="black"
)

plt.tight_layout()

plt.savefig(
    OUTPUT,
    dpi=150,
    bbox_inches="tight",
    facecolor="white"
)

plt.close()

print("Saved:", OUTPUT)
</code>

Run the Script

~/venvs/goes/bin/python /var/www/vhosts/uksmg.org/httpdocs/scripts/goes_xray_plot.py

CRON Job

Enter the following command as a cron job to run every 5 minutes:
/var/www/vhosts/uksmg.org/venvs/goes/bin/python /var/www/vhosts/uksmg.org.uk/httpdocs/scripts/goes_xray_plot.py >> /var/www/vhosts/uksmg.org.uk/goes_xray.log 2>&1