Documentation index

SSTV reference library

Use this index when a mode name is not enough. The library links the history of Slow Scan Television to the practical timing contracts behind Martin, Scottie, Robot, PD, Pasokon, MMSSTV, AVT, Wraase, FAX, and other analog SSTV families.

Learning route

From picture-by-sound history to per-mode timing

Read the history to understand why SSTV fits in voice-bandwidth radio.
Start receiving SSTV when you need a station checklist before the next pass.
Compare mode families before choosing a compatibility target.
Use the spec sheet when you need VIS, duration, raster, color model, or source notes.
Check public activity before assuming a satellite or event is currently on air.

Mode field guide

14 families

Family pages explain the operating role, signal shape, strengths, watch points, and mode rows for each analog SSTV group.

Browse the mode field guide

Cited spec sheet

85 rows

Filter by family, support status, duration, VIS or app identifier, color model, frame size, and line-timing notes.

Open the spec sheet

Packet image formats

SSDV packet reference

SSDV is kept separate from analog mode rows: it is packetised JPEG image data with headers, CRC32, and optional Reed-Solomon FEC.

Open the SSDV tables

Algorithm notes

JPEG fragments, MCU recovery, and FEC

Walk through encode and decode stages, including packet identity, MCU offset recovery, missing packets, and transport framing.

Read the SSDV algorithm notes

Packets before pictures

Field notes compare SSDV with analog SSTV and explain what a ground station should log before judging the final JPEG.

Read the SSDV ground-station note

DRM radio system

DRM robustness modes

Mode A through Mode E are DRM COFDM robustness profiles, with different guard intervals, carrier spacing, bandwidths, and service capacity.

Open the DRM tables

Algorithm notes

FAC, SDC, MSC, coding, and OFDM

Follow the DRM encode and receive path through energy dispersal, multilevel coding, interleaving, pilot cells, and guard intervals.

Read the DRM algorithm notes

Check the DRM signal first

Digital SSTV station notes should separate the RF/audio recording, DRM lock state, application object, and final recovered picture.

Read the DRM receiving note

Catalog coverage

46 app-supported rows

Generated from sstvparam.swift, including duration, frame, VIS/app identifier, porch timing, subcarrier, and tone range.

29 reference rows

Compiled from checked mode tables where duration, raster, VIS behavior, or line rate are published but the app does not implement the mode.

10 verification rows

Used for historical or conflicting entries such as secondary AVT rows, unknown VIS rows, and published collision notes.

Choose by operating situation

Short public satellite window

Start with the activity source. If the organiser names Robot 36 or PD120, follow that mode rather than guessing from audio alone.

Check source status

HF compatibility check

Compare Martin, Scottie, Robot, PD, and Wraase rows by duration, component sequence, VIS behaviour, and tolerance for a noisy channel.

Compare mode families

Implementation or decoder work

Use per-mode pages for timing fields, source notes, sample cards, FLAC audio, and round-trip receiver evidence where the app supports the mode.

Open the spec sheet

Bench evidence

Supported mode pages publish a generated colour test card, lossless audio encoded by the app transmitter path, and receiver loopback evidence after the FLAC has been restored to WAV. Reference-only modes still get raster matched test cards so uncommon rows remain inspectable.

How SSTV mode families evolved

Monochrome and early hardware: narrow information rate, simple video tone mapping, and receiver stability as the central problem.
Robot and VIS: machine-readable mode identification made automatic receiving more practical.
Martin and Scottie color modes: Martin's RGB sequence and Scottie's G-B-R color scan pattern became durable compatibility targets.
Pasokon and PD: longer transmissions trade time for larger images and higher fidelity.
MMSSTV extended and narrowband modes: software-era modes add extended or N-VIS style identifiers and narrower deviations.
Satellite practice: public ISS SSTV commonly favors highly compatible modes such as Robot 36 and PD120 when scheduled by operators.

What the tables are trying to answer

Can an automatic receiver identify it?

Classic modes usually use 8-bit VIS values; MMSSTV software-era rows can use extended identifiers, while AVT and some FAX-style rows need family-specific handling.

How much channel time does it need?

Short Robot and monochrome modes are useful for marginal paths. PD and Pasokon modes spend more time on larger frames and usually reward cleaner passes.

What color model is being scanned?

RGB, G-B-R, Y/R-Y/B-Y, and luma-only modes all fit inside the same audio tone idea, but the receiver has to know the component order and timing.

Family index

AVT FAX Kenwood FAST FM MMSSTV MSCAN Martin Monochrome PD Pasokon Proskan Robot Scottie Vester Wraase

Mode family comparison

Family	Typical role	Signal shape	Strength	Watch point
Martin	Classic HF color	RGB components with short sync/porch timing	Broad compatibility and familiar M1/M2 behavior	Longer than quick Robot modes
Scottie	Classic RGB color	RGB line sequence with Scottie timing	Good compatibility, including DX-oriented variants	Some historical tables disagree around DX variants
Robot	Fast color and monochrome	Y plus color-difference components	Very common, short transmissions such as Robot 36	Lower detail than long PD/Pasokon frames
PD / Pasokon	Higher-resolution color	Larger frames and longer scan durations	More detail for planned transmissions	Requires more pass time and cleaner channel conditions
MMSSTV	Software-era extended modes	MP/MR/ML and narrowband variants	Rich software compatibility and N-VIS style options	Less universal than Martin, Scottie, Robot, and PD
AVT / Wraase / FAX	Historical compatibility	Family-specific sync and component timing	Keeps uncommon analog SSTV modes documented	Several rows require source-by-source verification