mirror of
https://github.com/smittix/intercept.git
synced 2026-04-23 22:30:00 -07:00
500ddf59fe
Multi-arch Docker builds: - build-multiarch.sh: Cross-compile amd64+arm64 on x64 and push to registry, so RPi5 can docker pull instead of building natively - docker-compose.yml: Add INTERCEPT_IMAGE env var to support pulling pre-built images from a registry instead of local build - README.md: Docker build section rewritten with multi-arch workflow, registry pull instructions, and build script options Weather satellite antenna guide (sidebar panel): - V-Dipole: ASCII diagram, 53.4cm element length, 120 degree angle, materials, orientation, connection instructions - Turnstile/Crossed Dipole: phasing coax length (37cm RG-58), reflector distance (52cm below), RHCP explanation - QFH Quadrifilar Helix: design overview, materials, height (46cm), hemispherical gain pattern - Placement & LNA: outdoor requirements, coax loss figures, LNA mounting position, Nooelec SAWbird+ recommendation, Bias-T - Quick reference table: wavelength, quarter-wave, elevation, duration, polarization, APT/LRPT bandwidth Also added Weather Satellites and ISS SSTV to README features list, SatDump to acknowledgments. https://claude.ai/code/session_01FjLTkyELaqh27U1wEXngFQ
189 lines
12 KiB
HTML
189 lines
12 KiB
HTML
<!-- WEATHER SATELLITE MODE -->
|
|
<div id="weatherSatMode" class="mode-content">
|
|
<div class="section">
|
|
<h3>Weather Satellite Decoder</h3>
|
|
<p class="info-text" style="font-size: 11px; color: var(--text-dim); margin-bottom: 12px;">
|
|
Receive and decode weather images from NOAA and Meteor satellites.
|
|
Uses SatDump for live SDR capture and image processing.
|
|
</p>
|
|
</div>
|
|
|
|
<div class="section">
|
|
<h3>Satellite</h3>
|
|
<div class="form-group">
|
|
<label>Select Satellite</label>
|
|
<select id="weatherSatSelect" class="mode-select">
|
|
<option value="NOAA-15">NOAA-15 (137.620 MHz APT)</option>
|
|
<option value="NOAA-18" selected>NOAA-18 (137.9125 MHz APT)</option>
|
|
<option value="NOAA-19">NOAA-19 (137.100 MHz APT)</option>
|
|
<option value="METEOR-M2-3">Meteor-M2-3 (137.900 MHz LRPT)</option>
|
|
</select>
|
|
</div>
|
|
<div class="form-group">
|
|
<label>Gain (dB)</label>
|
|
<input type="number" id="weatherSatGain" value="40" step="0.1" min="0" max="50">
|
|
</div>
|
|
<div class="form-group">
|
|
<label style="display: flex; align-items: center; gap: 6px;">
|
|
<input type="checkbox" id="weatherSatBiasT" style="width: auto;">
|
|
Bias-T (power LNA)
|
|
</label>
|
|
</div>
|
|
</div>
|
|
|
|
<!-- Antenna Guide - detailed -->
|
|
<div class="section">
|
|
<h3>Antenna Guide</h3>
|
|
<div style="font-size: 11px; color: var(--text-dim); line-height: 1.5;">
|
|
|
|
<p style="margin-bottom: 10px; color: var(--accent-cyan); font-weight: 600;">
|
|
137 MHz band — your stock SDR antenna will NOT work.
|
|
</p>
|
|
<p style="margin-bottom: 10px;">
|
|
Weather satellites transmit at 137.1–137.9 MHz. The quarter-wave
|
|
at this frequency is <strong style="color: var(--text-primary);">~53 cm</strong>,
|
|
far longer than the small telescopic antenna shipped with most SDRs
|
|
(tuned for ~1 GHz). You need a purpose-built antenna.
|
|
</p>
|
|
|
|
<!-- V-Dipole -->
|
|
<div style="background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 4px; padding: 10px; margin-bottom: 10px;">
|
|
<strong style="color: var(--accent-cyan); font-size: 12px;">V-Dipole (Easiest — ~$5)</strong>
|
|
|
|
<div style="margin: 8px 0; padding: 8px; background: var(--bg-tertiary); border-radius: 3px; font-family: 'JetBrains Mono', monospace; font-size: 10px; color: var(--text-secondary); white-space: pre; line-height: 1.3; text-align: center;"> coax to SDR
|
|
|
|
|
===+=== feed point
|
|
/ \
|
|
/ 120 \
|
|
/ \
|
|
/ deg \
|
|
53.4cm 53.4cm</div>
|
|
|
|
<ul style="margin: 6px 0 0 14px; padding: 0;">
|
|
<li><strong style="color: var(--text-primary);">Element length:</strong> 53.4 cm each (quarter wavelength at 137 MHz)</li>
|
|
<li><strong style="color: var(--text-primary);">Angle:</strong> 120° between elements (not 180°)</li>
|
|
<li><strong style="color: var(--text-primary);">Material:</strong> Any stiff wire, coat hanger, or copper rod</li>
|
|
<li><strong style="color: var(--text-primary);">Orientation:</strong> Lay flat or tilt 30° toward expected pass direction</li>
|
|
<li><strong style="color: var(--text-primary);">Polarization:</strong> The 120° angle gives partial RHCP match to satellite signal</li>
|
|
<li><strong style="color: var(--text-primary);">Connection:</strong> Solder elements to coax center + shield, connect to SDR via SMA</li>
|
|
</ul>
|
|
<p style="margin-top: 6px; color: var(--text-dim); font-style: italic;">
|
|
Best starter antenna. Good enough for clear NOAA images with a direct overhead pass.
|
|
</p>
|
|
</div>
|
|
|
|
<!-- Turnstile -->
|
|
<div style="background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 4px; padding: 10px; margin-bottom: 10px;">
|
|
<strong style="color: var(--accent-cyan); font-size: 12px;">Turnstile / Crossed Dipole (~$10-15)</strong>
|
|
|
|
<div style="margin: 8px 0; padding: 8px; background: var(--bg-tertiary); border-radius: 3px; font-family: 'JetBrains Mono', monospace; font-size: 10px; color: var(--text-secondary); white-space: pre; line-height: 1.3; text-align: center;"> 53.4cm
|
|
<--------->
|
|
====+==== dipole 1
|
|
|
|
|
====+==== dipole 2
|
|
<--------->
|
|
90 deg rotated
|
|
+ reflector below</div>
|
|
|
|
<ul style="margin: 6px 0 0 14px; padding: 0;">
|
|
<li><strong style="color: var(--text-primary);">Elements:</strong> Two crossed dipoles, each 53.4 cm per side (4 elements total)</li>
|
|
<li><strong style="color: var(--text-primary);">Angle:</strong> 90° between the two dipole pairs</li>
|
|
<li><strong style="color: var(--text-primary);">Phasing:</strong> Feed dipole 2 with a 90° delay (quarter-wave coax section ~37 cm of RG-58)</li>
|
|
<li><strong style="color: var(--text-primary);">Reflector:</strong> Place ~52 cm below elements (ground plane or wire grid)</li>
|
|
<li><strong style="color: var(--text-primary);">Polarization:</strong> Circular (RHCP) — matches satellite transmission</li>
|
|
</ul>
|
|
<p style="margin-top: 6px; color: var(--text-dim); font-style: italic;">
|
|
Better than V-dipole. The reflector rejects ground noise and the RHCP phasing matches the satellite signal.
|
|
</p>
|
|
</div>
|
|
|
|
<!-- QFH -->
|
|
<div style="background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 4px; padding: 10px; margin-bottom: 10px;">
|
|
<strong style="color: #00ff88; font-size: 12px;">QFH — Quadrifilar Helix (Best — ~$20-30)</strong>
|
|
|
|
<div style="margin: 8px 0; padding: 8px; background: var(--bg-tertiary); border-radius: 3px; font-family: 'JetBrains Mono', monospace; font-size: 10px; color: var(--text-secondary); white-space: pre; line-height: 1.3; text-align: center;"> ___
|
|
/ \ two helix loops
|
|
| | | twisted 90 deg
|
|
| | | around a mast
|
|
\___/
|
|
|
|
|
coax</div>
|
|
|
|
<ul style="margin: 6px 0 0 14px; padding: 0;">
|
|
<li><strong style="color: var(--text-primary);">Design:</strong> Two bifilar helical loops, offset 90°</li>
|
|
<li><strong style="color: var(--text-primary);">Material:</strong> Copper pipe (10mm), copper wire, or coax outer shield</li>
|
|
<li><strong style="color: var(--text-primary);">Total height:</strong> ~46 cm (for 137 MHz)</li>
|
|
<li><strong style="color: var(--text-primary);">Loop dimensions:</strong> Use a QFH calculator for exact bending measurements</li>
|
|
<li><strong style="color: var(--text-primary);">Polarization:</strong> True RHCP omnidirectional — ideal for overhead satellite passes</li>
|
|
<li><strong style="color: var(--text-primary);">Gain pattern:</strong> Hemispherical upward coverage, rejects ground interference</li>
|
|
</ul>
|
|
<p style="margin-top: 6px; color: var(--text-dim); font-style: italic;">
|
|
Gold standard for weather satellite reception. No tracking needed — covers the whole sky.
|
|
</p>
|
|
</div>
|
|
|
|
<!-- Placement & LNA -->
|
|
<div style="background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 4px; padding: 10px; margin-bottom: 10px;">
|
|
<strong style="color: var(--accent-cyan); font-size: 12px;">Placement & LNA</strong>
|
|
<ul style="margin: 6px 0 0 14px; padding: 0;">
|
|
<li><strong style="color: var(--text-primary);">Location:</strong> OUTDOORS with clear sky view is critical. Roof/balcony/open field.</li>
|
|
<li><strong style="color: var(--text-primary);">Height:</strong> Higher is better but not critical — clear horizon line matters more</li>
|
|
<li><strong style="color: var(--text-primary);">Antenna up:</strong> Point the antenna straight UP (zenith) for best overhead coverage</li>
|
|
<li><strong style="color: var(--text-primary);">Avoid:</strong> Metal roofs, power lines, buildings blocking the sky</li>
|
|
<li><strong style="color: var(--text-primary);">Coax length:</strong> Keep short (<10m). Signal loss at 137 MHz is ~3 dB per 10m of RG-58</li>
|
|
<li><strong style="color: var(--text-primary);">LNA:</strong> Mount at the antenna feed point, NOT at the SDR end.
|
|
Recommended: Nooelec SAWbird+ NOAA (137 MHz filtered LNA, ~$30)</li>
|
|
<li><strong style="color: var(--text-primary);">Bias-T:</strong> Enable the Bias-T checkbox above if your LNA is powered via the coax from the SDR</li>
|
|
</ul>
|
|
</div>
|
|
|
|
<!-- Quick reference -->
|
|
<div style="background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 4px; padding: 10px;">
|
|
<strong style="color: var(--accent-cyan); font-size: 12px;">Quick Reference</strong>
|
|
<table style="width: 100%; margin-top: 6px; font-size: 10px; border-collapse: collapse;">
|
|
<tr style="border-bottom: 1px solid var(--border-color);">
|
|
<td style="padding: 3px 4px; color: var(--text-dim);">Wavelength (137 MHz)</td>
|
|
<td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">218.8 cm</td>
|
|
</tr>
|
|
<tr style="border-bottom: 1px solid var(--border-color);">
|
|
<td style="padding: 3px 4px; color: var(--text-dim);">Quarter wave (element length)</td>
|
|
<td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">53.4 cm</td>
|
|
</tr>
|
|
<tr style="border-bottom: 1px solid var(--border-color);">
|
|
<td style="padding: 3px 4px; color: var(--text-dim);">Best pass elevation</td>
|
|
<td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">> 30°</td>
|
|
</tr>
|
|
<tr style="border-bottom: 1px solid var(--border-color);">
|
|
<td style="padding: 3px 4px; color: var(--text-dim);">Typical pass duration</td>
|
|
<td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">10-15 min</td>
|
|
</tr>
|
|
<tr style="border-bottom: 1px solid var(--border-color);">
|
|
<td style="padding: 3px 4px; color: var(--text-dim);">Polarization</td>
|
|
<td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">RHCP</td>
|
|
</tr>
|
|
<tr style="border-bottom: 1px solid var(--border-color);">
|
|
<td style="padding: 3px 4px; color: var(--text-dim);">NOAA (APT) bandwidth</td>
|
|
<td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">~40 kHz</td>
|
|
</tr>
|
|
<tr>
|
|
<td style="padding: 3px 4px; color: var(--text-dim);">Meteor (LRPT) bandwidth</td>
|
|
<td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">~140 kHz</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
|
|
<div class="section">
|
|
<h3>Resources</h3>
|
|
<div style="display: flex; flex-direction: column; gap: 6px;">
|
|
<a href="https://github.com/SatDump/SatDump" target="_blank" rel="noopener" class="preset-btn" style="text-decoration: none; text-align: center;">
|
|
SatDump Documentation
|
|
</a>
|
|
<a href="https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weather-satellite-images/" target="_blank" rel="noopener" class="preset-btn" style="text-decoration: none; text-align: center;">
|
|
NOAA Reception Guide
|
|
</a>
|
|
</div>
|
|
</div>
|
|
</div>
|