User guide

Set your station

Every pass time on this site is for your station, so set it first.

1. Open the live map. In the header of the sidebar, click the station chip. It reads "Set station" until you set one. On a phone, press "Menu" first.
2. Type a Maidenhead locator, for example KN12pq (4, 6 or 8 characters, any case), or coordinates, for example 42.69, 23.32. Press "Set".
3. Or press "Use GPS" and allow location access in the browser.

The chip then shows your locator, with "GPS" after it if the position came from GPS.

What is stored in the browser

A station you typed is saved in your browser and used on your next visit. The satellite pages and the EME planner read it from there too. A GPS position is kept only as a 6-character locator, a square of about 5 by 2.5 km, not as exact coordinates. The map asks for GPS again on each visit; a station you typed replaces the GPS one. Your station is not sent to our server.

Pick satellites and read the map

My satellites

1. In the sidebar, next to "My satellites", press "Add". The window "Choose satellites" opens.
2. Search by name, NORAD ID or frequency, or use the filters All, Heard today, FM, Linear, Digi and Stations. Silent satellites stay hidden until you tick "Show silent".
3. Click a satellite to add it, or press "Add all shown". "Clear my list" empties the list.

The list is saved in your browser. "Share" copies a link to your list.

Everything above me

Press "Layers" on the map and tick "Everything above me". Satellites that are above your horizon now, but not on your list, show as small dots. Point at a dot to see its name and elevation. Click or tap it to preview the satellite: it gets a track, a footprint and a card in the sidebar. A preview saves nothing. Press "Add to my satellites" on the card to keep it. Clicking another dot, closing the card or clicking an empty spot on the map ends the preview.

The focus card, tracks and footprint

Click a satellite on the map, on the radar or in "My satellites" to open its card in the sidebar. It shows its status, the current or next pass with AOS, Max, LOS and Now, and its frequencies. Under "Display", "Tracks" chooses what is drawn on the map: "Focused" (the satellite on the card only), "Mine" (all your satellites) or "Off". The track is one orbit ahead. The footprint is the area where the satellite is above your horizon, with rings at 10° and 30° elevation.

Radar and sky view

The "Radar" tab shows the sky over your station: zenith in the middle, north at the top, every satellite that is above the horizon. The dropdown next to the tabs hides the ones below a chosen elevation.

On a phone, press "Follow compass" under the radar to turn it with the phone. For a view that follows the phone in all directions, open Sky view ("Sky view: look through your phone" under the radar, or the "Sky view" link on the map), press "Start" and hold the phone up. Tap a satellite to make it the target; an arrow at the edge of the screen shows where to turn.

Find a pass you can use

1. Add satellites to "My satellites" and set your station.
2. In the sidebar, open the "Passes" tab, next to "Radar". It lists the passes of your satellites for the next 24 hours: start (AOS) to end (LOS), duration, maximum elevation, direction, and a countdown.
3. Use the dropdown in the tab header (≥ 0°, ≥ 10°, ≥ 20°, ≥ 30°) to hide low passes. The choice is remembered.

Click the elevation badge of a pass for more. It shows when the peak is and the time spent above 10°, 30° and 60°, for example "Max 47° at 14:32 · ≥10° 14:28–14:36". A pass above 30° is usually easy to work.

A pass of a geostationary satellite reads "Always above the horizon".

"In eclipse: transponder off"

AO-7 and AO-91 work only while they are in sunlight. For these two, a pass that is entirely in the Earth's shadow is faded and marked "In eclipse: transponder off". A pass that crosses the shadow edge says "Enters eclipse at hh:mm:ss: transponder off after". This comes from the satellites' published operating rule and the computed shadow, not from a measurement. The satellite may behave differently. It is shown on the "Passes" tab and in the pass table of each satellite page.

Put a pass in your calendar

One pass

1. On the "Passes" tab of the map, or in the AOS column of the table on a satellite page, click the time of the pass. It has a dotted underline.
2. The panel "Add to calendar" opens under the row. Under "Remind me" choose 5, 10, 30 or 60 minutes before. The default is 10.
3. Press "Download .ics" to get a file for any calendar program, or "Google Calendar" to open Google Calendar in a new tab.

Google does not take a reminder from a link, so it uses your default reminder. The panel says so: "Google uses your default reminder". A second click on the time, or Escape, closes the panel. A pass that is already under way when the list is made has no button.

All passes of a satellite

On a satellite page, under the pass table, "Add passes to your calendar" has three links. "Subscribe" adds a calendar that updates itself with the next 7 days of passes (Apple Calendar, Outlook). "Google Calendar" does the same in Google Calendar, and "Download .ics" gives a one-time file. The link holds your 6-character locator.

Arrange a contact with another operator

To work a station far away through a satellite, you need a time when the satellite is above the horizon for both of you. On this site the other operator is your "Partner".

On the map

1. Set your own station first.
2. In the sidebar, under the station form, press "+ Partner". Type the other operator's locator or coordinates, for example KN34. You can add a callsign in "Callsign (optional)". Press "Set".
3. A chip "Partner KN34" appears (with a callsign, "Partner LZ2XYZ · KN34"), and an orange diamond marks the partner on the map. The chip's × turns the partner off; it stays in your saved list.
4. Open the "Passes" tab. A switch "My passes | With KN34" appears above the list. Choose "With KN34" to see the common windows: times when each of your satellites is above the minimum elevation for both stations. Each row shows the satellite, start and end, length, and the elevation at your place and theirs ("El. you / them"). The dropdown for the minimum elevation works here too.
5. Click the name of a satellite to put it in focus on the map.

The list has no rows when no common window falls in the next 24 hours. It then gives the distance between the stations. "Too far for these satellites" means that no satellite of your list can cover both stations at the elevation you chose, so waiting will not help: choose a satellite with a higher orbit or a lower minimum elevation.

Several saved partners. The site keeps up to 8 partners in your browser. Click the partner chip to open the list and pick another one; "rename" changes the callsign, "remove" forgets the partner, and "+ Add partner" adds a new one. One partner is active at a time. With saved partners and none active, the button reads "Partner: choose".

On a satellite page

1. Open a satellite page, for example from the catalogue, and make sure your station is set.
2. Under the pass table, find "Contact with another station". Enter the other operator's locator or coordinates, for example FN42.
3. Choose a minimum elevation: 0°, 5° or 10°. The default is 5°.
4. Press "Find common window". The table "Common window (local time)" lists the next two days, with the length of each window and the elevation for both stations, and the distance between the stations is shown below.

The block is not shown for geostationary satellites such as QO-100: they are always up for everyone in their footprint. If there is no window, the page says how far apart the stations are. "Too far for this satellite" means the stations are farther apart than this satellite can cover, even at its highest point.

Time of a common window. The time of a common window, in the "With KN34" list and in the table on the satellite page, is a button. It opens the same "Add to calendar" panel as a pass, so you can put the contact in your calendar.

Send the other operator a link

On the satellite page press "Copy link". The address then carries the other station and the elevation, for example ?with=FN42&el=5. On the map, "Share" copies a link that holds your satellites and, while a partner is set, ?with=. Your own station is never in the link: the person who opens it sees the windows from the station set in their own browser. A partner that comes from a link is used for that visit, but opening the link does not save it in your browser.

The partner you enter is saved in your browser and used on the other pages too: it fills the DX locator on the EME planner.

Work a pass

Live Doppler

Put the satellite in focus (click it) and read its card. Each uplink, downlink and beacon frequency is shown corrected for the Doppler shift of this second, with the shift in kHz next to it. For the uplink the card shows the frequency you should transmit on, for the downlink the one you should hear. Values on the satellite pages are nominal, without Doppler.

Under "Display", "Sound at AOS" plays a sound when a satellite of your list rises, and "Notify before passes" sends a notification 2, 5, 10 or 15 minutes ahead while the site is open in a browser tab or installed as an app.

A handheld on FM

A handheld has no automatic Doppler correction, so you change the channel by hand. On the page of an FM satellite, the section "Doppler plan for a handheld" does the calculation:

1. Choose the pass in "Pass" and, if there are several, the "Transmitter".
2. Read the table: channels in 5 kHz steps and the time to switch to the next one. Times are local.
3. Press "Download for CHIRP" and open the file in CHIRP (generic CSV). Copy the memories to your radio.

QO-100: Sun days

Twice a year the Sun passes behind the geostationary QO-100 and its noise rises over the transponder for some minutes. On the QO-100 page, the section "Sun in the QO-100 beam" lists the days of the coming season for your station and your dish diameter, and the moment to check your dish pointing. Find the page through the satellite catalogue.

EME planner

The EME planner is for moonbounce. Enter your locator and a band to see the best Moon days of the next 30, the windows shared with a DX station's locator, Doppler, spread and the EME beacons. Everything is computed in your browser, and the address holds the form, so you can share a plan.

Embed the pass widget

A club or personal website can show the next passes over its own locator. The widget page builds the code: pick the satellites and the locator, check the preview and paste one line into your page.

Privacy

Your station, your satellites, your partner and your settings stay in your browser. A calendar link and the widget carry a 6-character locator to our server, which uses it only to compute the passes. Read the details in the privacy policy.