From jacob.oost at odysseysr.com Mon Nov 4 16:12:23 2024 From: jacob.oost at odysseysr.com (Jacob Oost) Date: Tue, 5 Nov 2024 00:12:23 +0000 Subject: [Spice_discussion] Two-vector frame accuracy Message-ID: Can somebody clarify something in the documentation about two-vector frames? On the page https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/frames.html we have: "R(t) is defined via a two-vector frame using a velocity vector. The acceleration associated with the velocity vector is required to compute d(R(t))/dt, and this acceleration must be computed numerically. The results are likely to have at best single precision validity." However, on the page https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/Tutorials/pdf/individual_docs/24_dynamic_frames.pdf on slide 58 we have a similar sentence followed by this: "However, if velocities are "well-behaved," numerically derived acceleration can be quite good. Example: GSE frame." How should I determined if velocities are well-behaved? Do any DE430/440/etc. velocities count as well-behaved? Would this imply that a custom Earth-Moon rotating frame would be based on well-behaved velocities? What about the velocities of, say, the Gateway reference ephemeris SPICE kernel? Could I make a VUW frame centered on that ephemeris and expect it to be well-behaved? In case it helps, this question arose from the context of either using SPICE frame kernels with SPICE frame transformation routines OR using custom frame transformation code in which the simplifying assumption dh/dt=0 (at the instant of the transformation) is made to avoid numerical issues. Thanks! -------------- next part -------------- An HTML attachment was scrubbed... URL: From sylvain.guillet at tutamail.com Sat Nov 23 13:12:56 2024 From: sylvain.guillet at tutamail.com (sylvain.guillet at tutamail.com) Date: Sat, 23 Nov 2024 22:12:56 +0100 (CET) Subject: [Spice_discussion] Natural language interaction with SPICE kernels Message-ID: Dear Spice Community, I am thrilled to announce the latest update to IO Aerospace Web application, introducing AI-powered natural language interaction with SPICE kernels and a comprehensive suite of astrodynamics tools. ? Key Highlights: AI Assistant for Natural Language Interaction: Integrated into our web application, the AI Assistant enables end users to interact with SPICE kernels effortlessly using natural language, providing precise data and advanced computational results. Extensive Toolset for Astrodynamics Analysis: The AI Assistant offers a rich array of capabilities, including: Celestial Body Analysis: Retrieve ephemeris and celestial body properties. Time Tools: Convert between date/time formats and get current time in various systems. Orbital Parameters Conversions: Seamlessly switch between Keplerian, equinoctial elements, and state vectors, or convert to specific reference frames or equatorial coordinates. Geometric event finder: Solve complex constraints like coordinates, distances, and occultation events. Ground Station Observations: Calculate planetodetic coordinates, state vectors, horizontal coordinates, and deep-space station reference frames. ? What?s Next: This update is a major step toward deeper AI integration in astrodynamics workflows. Future releases will continue to enhance automation, optimization, and user interaction for advanced applications. ? Useful Links: Web application Website Project Download latest version We are excited to see how these innovations empower your projects. Your feedback is invaluable as we continue to refine and expand the platform. Thank you for being part of our journey! Best regards, Sylvain Guillet Founder, IO Aerospace Community -------------- next part -------------- An HTML attachment was scrubbed... URL: