Select Spacecraft
This provides a list of Earth Observing spacecraft plus a few other interesting objects. There is also an option to specify a "custom" spacecraft if the object you're interested in is not on this list.
This provides a list of Earth Observing spacecraft plus a few other interesting objects. There is also an option to specify a "custom" spacecraft if the object you're interested in is not on this list.
Each orbiting object is assigned an identifying number by NORAD. If you select a spacecraft from our list, this field will be updated automatically. If you change this value manually, the spacecraft list will be updated to the spacecraft matching your value, or "custom" if your spacecraft is not on our list.
The ground location the overpass prediction is being generated for. A large list of ground locations is provided, or you can manually specify the latitude and longitude, in degrees, for your location. The latitude and longitude will be automatically set for the listed locations.
To manually specify a latitude/longitude, enter the latitude and longitude in degrees in the appropriate fields. Values must begin with a digit, and may include a decimal point. Do NOT include a sign (+ or -) in these fields, instead, select from the North/South and East/West pulldowns as appropriate. The locations list will set itself to "Specify Lat/Long" if you manually update the latitude or longitude.
Overpass predictions start at 00:00:00 UTC on the date specified. Because overpass predictions become less reliable as you get farther from the satellite's orbit data "epoch date" (the time/date of the observations from which the data was derived), we only offer +/- one year from the current year - and that is primarily to accommodate predictions just before or after New Years Day. We use the most recent satellite orbit data available.
The number of days to generate predictions for. We limit this to 14 days in order to keep the load on our server managable. You can produce longer predicts by running the predictor multiple times with start dates set 14 days apart; do note that predicts become less reliable as you move farther from the satellite's "epoch date" (see Predict Start Time, above.)
The minimum angle the spacecraft must be above the horizon before it is reported as making an overpass. If a value of 30 degrees is selected, for example, and the spacecraft's maximum elevation is 24 degrees for the pass, the pass will not be reported. Overpass start and end times will be reported as the time when the spacecraft rises above / drops below the specified elevation.
This parameter is only used for the Detailed Overpass Prediction format, it is not used in Overpass Summary reports.
Two reporting formats are provided.
Detailed Overpass Predictions provides one line of spacecraft position information for every time step (default 20 seconds) during overpass. A 10 minute overpass would thus have 30 lines of position information.
Overpass Summary provides a one-line summary for each overpass, indicating the time and location of spacecraft rise, maximum elevation, and set.
Output field descriptions are included with the Overpass Prediction reports.
By default, time will be computed and displayed in Universal Time (UTC), also known as Greenwich Mean Time (GMT). An alternate time zone may be selected from this list, or you can indicate that you wish to specify the offset from UTC manually (required if your preferred time zone is not on the list).
The offset, in fractional hours, from UTC to be used in computing and displaying time. This value will be set automatically if you select a time zone from the "Display Time As" list. If you specify this value manually, enter a plus or minus sign, the number of whole hours of offset from UTC, and optionally a decimal point and up to two digits for the fraction of an hour. Do not enter the offset in hhmm format. Newfoundland time would be expressed as -3.50 (-2.50 in the summer), and Nepal would be +5.75. By default, this value is +00.00, corresponding to UTC.