Running STK with SOCRATES
If you are already a licensed user of STK, it is fairly straightforward to use STK to perform full-fidelity, 3-D interactive analysis with SOCRATES. There are, however, several things you must do to ensure smooth operation.
Performing conjunction analysis in SOCRATES is designed to take advantage of the latest features in STK, and all development and testing to date has been done using STK 6.2.1 to 11.4.0. With additional capabilities being added in STK to support SOCRATES analysis, however, you'll want to upgrade to the latest version to ensure you can take advantage of all the latest features.
Of course, to run STK/CAT to perform conjunction analysis, you must have the proper STK licenses. If you do not already have the correct licenses and would like to check out this capability, you may request a demo license in order to evaluate the power of STK to perform conjunction analysis. Be sure to say that you're evaluating SOCRATES so that you'll get the right set of licenses.
With increasing security awareness on the Internet, Microsoft has now configured Internet Explorer, by default, so that it will not allow the launching of ActiveX clients. Unfortunately, you will need to do so in order to run STK from SOCRATES. In order to properly configure Internet Explorer to allow STK to run, you will need to look under Tools and select Internet Options and then go to the Security tab. Under Custom Level, you will need to change the setting for "Initialize and script ActiveX controls not marked as safe" to something other than Disable. While you could do this for the Internet Zone, it is highly discouraged since this setting will apply to all Internet sites. My recommendation would be that you add celestrak.com to your Trusted Sites and use the default security settings there. If you are uncomfortable leaving any of the settings set to Enable, I recommend that you change them to Prompt to ensure that nothing can run without your approval. Of course, you should feel free to consult your system administrator if you are unsure about the appropriate course of action.
Now that you have taken care of the obligatory configuration issues, you are finally ready to run the conjunction scenario in STK. There is an Analysis button for each conjunction and clicking on it will launch a separate browser window. That window will contain the TLEs (and any other data, such as size or covariance) used to generate that portion of the SOCRATES report along with buttons to launch STK. Initially, only the Launch STK button is enabled since this step must be done first.
Once you've clicked on Launch STK, if you configured your browser to prompt before initializing the STK ActiveX component, you will be prompted as to whether you want to allow this interaction. You must answer Yes to continue.
Once STK has launched, the only button enabled will be the Build Scenario button. Clicking on this button will create the STK scenario, set the appropriate time parameters, create the conjuncting satellites—including selecting the appropriate models and attitude, if known—and then create the AdvCAT object and perform the necessary computations. When STK is ready, your browser window will show only the time selection buttons enabled.
At this point, you can begin working with this conjunction scenario in STK. You may now use the browser buttons to go directly to the beginning of the computation threshold (currently set at 5 km), the time of closest approach, or the end of the computation threshold. Try clicking the first button and then clicking the play button in STK to watch the conjunction unfold. Of course, you can also change your viewpoint and manipulate STK as you would with any scenario.
The top priority for enhancements to this capability is to ensure the highest fidelity of the scenario circumstances. Work is being done to ensure the appropriate model is selected, if available, and to apply the appropriate attitude, if known. If the attitude is unknown, an attitude uncertainty sphere is placed around the object to represent this uncertainty. Database development and validation is underway to ensure the most reliable size information is also available. And, work is also underway to generate more realistic covariance data to more faithfully represent the uncertainty associated with each object's position.
I hope you will find this a useful tool and welcome your questions, comments, or suggestions for improvements. — T.S. Kelso
|TLE Data||Space Data|