NADIR

—— UTC

AOS · START

——ADELAIDE · 34°55′ S 138°36′ E

The Earth, read in strips.

Swathe Orbital designs, builds and flies a small constellation of imaging satellites from the middle of Adelaide. Each one records the ground beneath it in a narrow strip as it passes, and we send you those strips as pictures and plain notes on crops, water, fire scars and coastlines.

Ask for imagery

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DRAWN LIVE · REAL SUN AND COASTS · ILLUSTRATIVE ORBITS
SWATHES DRAWN WIDER THAN LIFE

With JavaScript on, this paragraph says where the Sun is overhead now, how long until sunset or sunrise in Adelaide, and which of our satellites passes over the city next.

Press an amber figure to see how this page worked it out.

WORKED OUT IN YOUR BROWSER

P-UTCUTC

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P-SUN——

SUBSOLAR ——

NIGHT FROM ——

P-FLEET——

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P-NEXT——

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Illustration: the Earth seen from above northern Australia at the March equinox, the continent in daylight and the dawn line over the Indian Ocean — Illustration: the Earth at the March equinox, 00:00 UTC

STRIP 01 · FLEET · —— UTC

Two planes of satellites, each keeping its hour.

ILLUSTRATIVE ORBITS · SAMPLE ELEMENTS, SO THIS PAGE HAS SOMETHING TRUE TO COMPUTE

Each plane crosses the equator at the same local sun time every day: plane A heading south at 10:30 in the morning, plane B heading north at 13:30 in the afternoon. Shadows fall the same way from one picture to the next, so a paddock in March can be set beside the same paddock in May.

The morning plane’s lower Sun brings out relief. The afternoon plane often arrives after fog and low cloud have lifted.

The orbits run a little past the poles, slightly against the Earth’s turn, so every track leans west of north or south. While a satellite goes once round, the Earth turns —— beneath it, and its next pass lies that much further west.

WORKED OUT IN YOUR BROWSER: ——

SUNLITSHADOWHEADING

STRIP 02 · PASS · —— UTC

The next daylight pass over South Australia.

With JavaScript on, this log follows the next daylight pass over the state, line by line.

P-SAT——

LAT: ——
LON: ——
ALT: ——
HEADING: ——
LIGHT: ——

The camera records the ground one line at a time.

That strip is a swathe. Each of our satellites carries a camera that looks straight down. It does not take a picture the way a phone does: it records one thin line of ground across its path, then the next, then the next, as the satellite moves. Line by line they add up to a long strip of picture, as wide as the camera sees and as long as the pass. That strip is where our name comes from, and from here on you read this page inside one.

STRIP 03 · SEE · —— UTC

What a strip of ground can show.

The morning plane’s longer shadows show relief; the afternoon plane’s shorter ones show colour and cover.

P-SAT——

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NEXT OVER ADELAIDE ——

Crops

Paddock by paddock, season by season: where the crop is up, where it is thin, where the stubble lies.

It shows where; a visit shows why.

Water

Dams, channels and lake edges, filling after rain and drying back.

It shows the edge of the water, not what is in it.

Fire scars

Where the ground has burnt, where the fire stopped, and how it greens again.

It shows the scar, not the day of the fire.

Coastlines

Sand, shallows and the line between them, and how that line moves over the years.

It shows the shore at the moment of the pass.

LINE STUDIES OF THE KIND OF GROUND WE IMAGE · NOT SWATHE PICTURES

A picture shows the ground; it does not explain it.

STRIP 04 · TODAY · —— UTC

When the satellites pass over Adelaide.

P-NEXT——

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Passes more than ten degrees above Adelaide in the next day of this page’s model
LOCAL TIME · ADELAIDE
SAT	RISES	HIGHEST	SETS	UP	LIGHT
WORKED OUT IN YOUR BROWSER: ——

Worked out in your browser from illustrative orbits. The Sun and the clock are real.

ADELAIDE TODAY——

SUNRISE: ——
SOLAR NOON: ——
SUNSET: ——

The cameras work only where the ground is in daylight.

STRIP 05 · ASK HOW · —— UTC

How to ask for a picture.

DRAW THE AREAA PADDOCK, A CATCHMENT, A STRETCH OF COAST
NAME THE SUBJECTCROPS, WATER, FIRE SCARS, COAST
SET THE WINDOWFIRST AND LAST DATE
CHOOSE THE LIGHTMORNING OR AFTERNOON PLANE
CHECK THE PASSESWE LIST THEM FOR YOU
CONFIRMWE PLAN THE CAPTURE

P-NEXTMODEL

NEXT DAYLIGHT PASS OVER ADELAIDE IN THIS MODEL: ——

A satellite can only picture ground it flies over, in daylight, under a clear sky. So a request starts with the ground and the dates, not the picture. We check which passes cover your ground inside the window, and in what light, and send you the list. You choose; we plan the capture. Cloud is the one thing we plan around but do not control: if it covers your ground on the day, we tell you and try the next pass inside your window.

INSET · SOUTH AUSTRALIAMODEL

With JavaScript on, this inset draws the next daylight passes over the ground you choose.

LATITUDELONGITUDE

NEXT DAYLIGHT PASSES · —— · MODEL

The next three daylight passes whose drawn swathe covers the chosen point
SAT	DAY	LOCAL TIME	HEADING	SUN
WORKED OUT IN YOUR BROWSER: ——

Worked out now, in your browser, from illustrative orbits, with the camera looking straight down.

Tell us the ground and the dates; we plan the passes.

STRIP 06 · DELIVERY · —— UTC

How the pictures reach you.

Recorded. The camera records the swathe. Stored. It is kept on board until an antenna is in reach. Sent down. It is sent down during a ground contact. Corrected. It is lined up with the map and adjusted for the terrain and the light. Checked. A person looks at it before it goes. Delivered. You receive map-ready picture files, or the analysis you asked for, such as an area of burnt ground or a change in a waterline, with a plain note on what the picture shows and what it does not.

P-CONTACT——

With JavaScript on, this line names the next contact with our antenna near Adelaide, in this page’s model.

A white dish antenna on a bare rise at dusk, tilted towards the sky, beside a small hut with one warm light. — ILLUSTRATION · A GROUND ANTENNA AT DUSK

Pictures wait on board until an antenna is in reach.

STRIP 07 · BUILD · —— UTC

Designed, built and flown in Adelaide.

We design the spacecraft and the camera it carries, build and test them in our clean room in the city, and fly them from a console in the same building.

When something needs changing in orbit, the people who built it are the ones at the console.

BUS

Holds it together, points it and keeps it warm.

CAMERA

Looks straight down and records the ground line by line as the satellite moves.

POWER

Solar panels charge the batteries in sunlight for the time in the Earth’s shadow.

WORKED OUT IN YOUR BROWSER: ——

RADIO

Takes each plan up and brings the pictures down when an antenna is in reach.

A small imaging satellite with folded solar panels and gold foil on a grey test stand in a clean room, two technicians in full white coveralls working beside it. — ILLUSTRATION · A SMALL IMAGING SATELLITE ON A TEST STAND

STRIP 08 · REAL · —— UTC

What on this page is real.

The Sun’s position is worked out for this minute, good to about a minute.
The coasts come from Natural Earth’s public-domain land map.
The eight satellites and their orbits are illustrative, drawn for this page.
Swathes are drawn far wider than a camera records, so you can see them at this scale, and “camera on” in the pass log is this model’s choice, not a planned shot.
The pictures are illustrations, not Swathe pictures.

ADELAIDE’S CLOCK——

ACST is UTC+9:30 and ACDT is UTC+10:30, read from your browser’s zone data.

ILLUSTRATIVE ELEMENTS
PLANE	CROSSES EQ.	INCL.	HEIGHT	MEAN ANOMALY AT EPOCH
A · MORNING · A1–A4	10:30 S	97.44°	510 km	0, 90, 180, 270°
B · AFTERNOON · B1–B4	13:30 N	97.44°	510 km	45, 135, 225, 315°

BOTH PLANES · PERIOD 94.89 min · EPOCH 1 SEPTEMBER 2026, 00:00 UTC · SEMI-MAJOR AXIS 6888.137 km · ECCENTRICITY 0.0011 · ARGUMENT OF PERIGEE 90°

Each frame solves Kepler’s equation for eight satellites by Newton’s method; this one took —— steps. The planes keep their hour because the Earth’s equatorial bulge turns each one once a year, in step with the Sun.

“Over Adelaide” means more than 10° above our Adelaide horizon. A ground contact means more than 5°. AOS and LOS, at the top and the foot of this page, mark where a pass begins and ends: acquisition and loss of signal.

The Sun and the coasts are real; the satellites are not.