# Questions tagged [ground-track]

Questions regarding the path of a point directly below an object in space.

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### How can I plot ground tracks on the surface of the Moon?

I'm curious if there's a module or Python library capable of plotting ground tracks on the Moon's surface, similar to how Skyfield or Astropy functions. I understand that Two-Line Elements (TLEs) are ...
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### What are some best practices for coding a satellite orbit propagator and ground track plotter?

I've seen interesting projects like this and I've been doing a decent amount of orbit propagation (numerically integrating state vectors, accounting for perturbations, etc.) in python and animating ...
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### What are the factors affecting a satellite's Repeat Ground Track period?

I understand the Repeat Ground Track (RGT) period of a satellite will be affected by its altitude. A similar post: How Do I determine the ground track period of a LEO satellite, describes a simple ...
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### How does the Gpredict software algorithm track satellites?

I was wondering how Gpredict calculates the ground tracks, Lat, Long and elevation based on a ground station. If I understand correctly, Gpredict takes the values from a TLE (Two-Line Element) set, ...
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### How to convert Geocentric Coordinates to ECEF using Skyfield?

I'm trying to obtain ECEF coordinates from geocentric coordinates and then plot the ground track using the subpoint function. Any advice? My objective is to create an accurate ground track. Additional ...
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### TLE propagation, I don't understand which time should I use in (t - t_0)?

I'm trying to plot ground tracks with the help of TLE data. However, there are some equations that contain "times", and I can't understand which time I should use and format. Like for ...
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### Geofence - satellite contact time

I need to find the access/contact times for a satellite passing through a random geofence (polygon). Is there a python library or any code to integrate the geofence to the orbit of the satellite to ...
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### Revisit time estimation for a SAR constellation

I am studying satellite coverage analysis and I have read something about revisit time I did not understand. you can increase and increase the number of satellites to further improve the revisit time, ...
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### Modelling ISS orbit in GMAT

I am a complete newbie in all things space related. I am trying to work out how I can model the orbit of the ISS in the NASA open source tool GMAT. I can get the TLE for ISS (ZAYRA) from space-track....
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### Is it possible to determine the classical orbital elements for an Elliptic Repeating SSO?

As in the title, it is possible to have a repeatable Sun-synchronous orbit but with an elliptic eccentricity? If yes, which equations I have to consider to determine its classical orbital elements?
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### Repeat ground track with 1 day repetition

I'm struggling with a doubt regarding repeating ground tracks (RGT). I've a satellite in a LEO circular orbit with a predefined non-polar inclination (64°) and I want to determine the needed semi-...
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### satellite ground track in skyfield

I'm trying to get the geographic location (longitude & latitude of a satellite) converted from the position in space for example: position = (7033.45648791, 178.93192295, 0.00290722) Km. longitude ...
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### satellite ground track calculation

I'm trying to calculate the ground track of an earth-orbiting satellite (Longitude, latitude) I found this handy way on the documentation but it's good when trying to find a single point what if I'm ...
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### What is the ground track map at ground control used for?

My earliest and also most-recent memories of the interiors of ground control stations feature a huge wall of monitors, with the largest and most-central displaying the ground track of the vessel under ...
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### Why did Unity 22 flight plan call for such a large horizontal velocity during its weightless phase? (1085 kph) Why not go straight up instead?

A quick check of the videos shows Unity 22's apogee of over 86 km, and at that point the displayed speed is 674 mph or about 1085 kph or 18.1 km per minute. During the four minutes of being weightless ...
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### Unity 22's ground track; which direction was it moving horizontally at 1085 kph during its weightless phase?

update: According to The Newyorker's The Red Warning Light on Richard Branson’s Space Flight there is FR24 data available. A quick check of the videos shows Virgin Galactic's Unity 22's apogee of ...
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### Plotting satellite ground track with calculated latitude and longitude at a given moment

I have obtained the Classical Orbital Elements for a satellite on a given epoch, and now I would like to plot them on a 2D map. ...
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### Is it possible to predict if an orbiting satellite will pass over a given point on Earth after n periods?

I'm learning basic astrodynamics, and I have a question that I cannot find on the Internet (maybe I'm not looking hard enough). My question is, is there a way to predict how many periods would a ...
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### Why will it take a couple of weeks to complete CRYOSAT 2's orbit raising of a few hundred meters?

The BBC's Esa and Nasa line up satellites to measure Antarctic sea-ice says: Authorisation was given on Tuesday for Europe's Cryosat-2 spacecraft to raise its orbit by just under one kilometre. This ...
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### Why are ICESAT-2 and CRYOSAT 2 both at inclinations of almost exactly 92 degrees?

The BBC's Esa and Nasa line up satellites to measure Antarctic sea-ice says: Authorisation was given on Tuesday for Europe's Cryosat-2 spacecraft to raise its orbit by just under one kilometre. This ...
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### Calculate Satellite ground track

I'm trying to find equations to calculate satellite position based on orbit parameters and given time. What I currently have is a mess that is basically giving me bunch of garbage. What is latitude ...
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### If the Earth spun clockwise, would Florida have still satisfied the requirements for the US launch center in the 1960's?

In a comment under the question If the Earth spun clockwise, how would that affect Space Exploration? I wrote: Kennedy Space Center would be a lot closer to JPL; not sure what all happens with the ...
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### Analytical expression for the ground track of the International Space Station

For a maths task in school, I am investigating the orbit of the International Space Station around the Earth. I understand that when the 3D movement in space is represented on a 2D surface, the ...
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### Why do GTO launches from Baikonur launch to the northeast? [duplicate]

According to this article from Discover magazine, the flight paths of most rockets launching out of Baikonur pass over the Altai region of Russia (this has the side effect of large quantities of spent ...
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### Rocket launch ground track mapper

I'm looking for a tool for plotting the ground tracks of rocket launches at particular inclinations from particular launch sites, but haven't found anything so far; can anyone help me with this?
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### Is it possible to plot the ground track of a satellite with just azimuth & elevation angles without range?

I came across this question on StackOverflow about Satellite Trajectory plot. In the code mentioned in the question, the user takes only the Azimuth & Elevation angles (radians) & converts ...
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### How do I determine the ground-track period of a LEO satellite?

I was analyzing a LEO satellite with polar orbit for work purposes. I am relatively new to the field of Satellite orbits. I know that TLE can give information about the current & future orbits ...
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### What does the ISS ground track look like during periods of high solar beta?

These tweets about how sometimes the sun doesn't set on the International Space Station for multiple days made me realize I still have trouble visualizing solar beta angles. Does anyone have a ...
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### What kind of orbit makes this wave shaped ground track?

Here is a screen shot from NY2O of the ground track from GSAT-6A (43241, 2018-027A). What kind of orbit can make this wave shaped ground track?
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### How are impact probability maps rigorously calculated?

This is one example of an impact probability map. It was posted in this question and is from Aerospace Corporation. But My question is about the process, not this particular map, although it is a good ...
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### Tiangong-1 reentry impact place probabilities

Following all the news concerning Tiangong-1, I have seen the following plot made by the Aerospace Corporation where Blue area: null probability of impact Yellow area: high probability of impact ...
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### Clarify algorithm finding satellite ground track and orbit position

I try to plot satellite ground track. I found lots of formulas but hardly find algorithm which describe how to uses them one-by-one and step-by-step. As I understand the algorithm will be: 1) Get ...
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### Satellite Ground Track From ECEF Frame Position And Velocity Vector

The above question may sound naive. I am trying to understand how satellite ground track can be computed when satellite position and velocity vectors are available from on-board GPS receiver of a low ...
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### Ground longitude/latitude under a satellite (cartesian coordinates) at a specfic epoch

The script I'm wanting to develop uses the cartesian coordinates (XYZ) from a satellite, and in conjunction with the range, elevation and azimuth from a location, I then take a satellite’s orbital ...
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### Drawing ground station coverage circles

I'm trying to make a little application to draw ground station coverage circles (before anyone suggests using other software, I enjoy making these kinds of things myself!) I already have code that ...
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### TLE data: how to update the date?

Having a TLE data, how do I update it with -let's say- today's date ? I have the TLE of the ISS, I concluded that in order to have the location of the satellite at the moment, columns 21 to 32 should ...
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### Ground tracking : converting TLE to another format

After research, I knew that a certain TLE data can be transformed into another format (I thought about ECI) so geodetic conversion can be applied (to fetch coordinates which can be plotted) . I wanted ...
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### How long does one orbit around the Moon take in a typical parking orbit for a stage a lander is going to meet?

I have been pondering the relative advantages of placing a base near the Moon's equator, or at the poles. The poles have been defended as having a superior business case because of deposits of ...
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### Diurnal Signature of Earth in Angular state tracking

'Diurnal signature of the earth related to the the rotation of the earth is utilized and 24 hours of amplitude and phase data is used along with Ranging and Doppler shift data to calculate Angular ...
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### Does mission control track craft in an adjacent orbit on the world map?

shows the world map screen at the centre. I'm probably wrong about this (feel free to shoot me down) but the map up there appears to render what look like 3 different orbit tracks. Why are there 3 ...
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### Calculate Satellite Coordinates From TLE Data

I know it is not that hard for those familiar with the equations for it, but I am having trouble with the math. In order to fully understand the orbit elements of TLEs I read this which I found very ...
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