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4

First, the SGP4 propagator is meant to propagate TLEs. He takes a TLE and a time since the TLE's epoch as inputs and outputs a position and a velocity. By selecting several times, you get a trajectory. In STK, if you have a trajectory generated by some other method, i.e. the TwoBody propagator or the HPOP propagator, then STK can estimate a TLE that would ...


4

As far as I can tell, this is nothing to worry. What goes into a TLE is a specific kind of average elements, which are meant to simplify short-term propagations. Here "mean" does not imply a time-averaged value, but rather the result of some specific mathematical transformations. This paper explains it fairly well, but notice it uses a theory different than ...


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Your variable root is of type IAgStkObjectRoot. If you search the Programming Interface Help, there are five save related methods for this type. These include Save() and SaveAs() So the easiest implementation would be: root.Save() which will save the scenario in the Documents\STK folder. If you want to control the specific location to save to you can try:...


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If your field of view defined as a typical solid angle, as shown on Wikipedia, then you'd define the half angles as the half of 100x100: 50x50. STK (and probably other modeling tools) accounts for the visibility of a sensor using a dual-conic model similar to an eclipsing model when assuming spherical celestial objects. Am I missing something?


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The New Horizons mission tutorial you refer to may come from our blog here. You'd have to do something similar. Astrogators Guild Blog For multiple flyby missions, Marty Ozimek and Justin Atchinson at APL did a great job of describing a similar problem with multiple flybys here: APL Example


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You will see this STK behavior with both UT1-UTC and with polar motion parameters. In STK, the default Earth Orientation Parameters file EOP-v1.1.txt only goes back 5 years. I'm guessing this is for quick loading. It also goes into the future with predictions by for about 1 year HOWEVER, STK also has a much larger EOP file that goes all the way back to ...


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This is a partial answer, and I think it would be good to have confirmation from someone who knows more about this than I do. After my previous answer I did some more searching, and found History of the SGP4 Propagator on the STK website. It seems that this happened a lot earlier than I'd originally thought! In the mid- to late 1970s, the SGP4 was modified ...


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For your own calculations, whenever you have a case of zero (or very small) eccentricity you may need to handle them differently and just choose an arbitrary argument of periapsis, perhaps zero. What does "very small" eccentricity mean for you? Small enough so that it doesn't make a difference (your orbit doesn't deviate from a circle by more than your ...


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You aren't using the follow segment properly. A follow segment is normally used at the begging of the MCS to replace either a launch segment or an initial state. It grabs a state (or perhaps an entire ephemeris) from another satellite in STK and then propagates forward from that state according to the segments of the MCS. What you've done by putting the ...


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From what I can tell from the parameters in your screenshots, the program has performed a perfectly valid optimisation. What's more concerning is that the text in you question doesn't match the parameters clearly shown in the screenshots. If there's a configuration page where does values are actually used, why is this not included in the question? The ...


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I believe this will work, although I haven't fully tried it out. You should be able to do this on both satellites, or on just one satellite. There may be other ways of doing it as well. I will assume we are only making the changes on one satellite. In your Propagate segment within Astrogator, set up a new "R Magnitude" stopping condition. ...


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I was trying to prepare an report for the electric thrust LEOP by STK. This report was going to include satellite x, y , z axes + some other satellite related angles (which were all created by myself using vectors) and finally access times with respect to the five different ground stations separated all around the world to satisfy the LEOP requirements. Even ...


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The video look and feel makes me think it was generated by AGI, so you could easily mail support@agi.com The short answer, is that you cannot do it just out of the box. You have to generate pointing data external to STK and feed it in as a .sp file. The external data file could be generated with Matlab, python, or any other tool of your choice. AGI has a ...


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The full answer is beyond the scope of StackExchange. A quick Astrogator tutorial for earth departure to Mars orbit can be found here. Ultimately you will need to use b-plane targeting if you want to get anywhere close to a gravity assist. Even for just simple targetting you will need to know the rough departure asymptote (normally from a Pork Chop plot) ...


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