Speaker
Boris Semenov
(NASA/JPL)
Description
The WebGeocalc tool (WGC) provides a web-based graphical user interface to many of the observation geometry computations available from the "SPICE" system (SPICE=Spacecraft, Planet, Instrument, Camera- matrix, Events; see http://naif.jpl.nasa.gov). It is based on client-server architecture. A user selects a computation and computation parameters using GUI widgets in a standard Web browser. The request is sent to a WGC geometry server that performs the computation and sends results back to the client.
WGC can compute various geometric parameters such as positions, orientations, and surface intercept coordinates for a given time or a series of times; perform geometric event searches for time intervals when a geometric parameter had a particular value or when a geometric condition is met; and perform time conversions. By a simple drag-n-drop action output value or time intervals from one WGC computation can be saved within a WGC session for use in subsequent computations, allowing users to perform cascading geometric event finder searches, with output from one search being used as input for the next one. Saved intervals can also be used to compute geometric parameters over a time window retuned by a search.
WGC offers many useful features such as plotting results and downloading results. It can plot geometric parameters versus time and versus each other, with both kinds of plots providing zoom capability, with ability to return to the previous or initial zoom levels. It presents numeric results in a scrollable table that can be downloaded in MS Excel, CSV, and simple text format.
Currently the NAIF group at JPL operates a WGC server (see http://naif.jpl.nasa.gov/naif/webgeocalc.html) that has access to all data on the NAIF web site. This server is configured to provide easy access to generic SPICE kernels and to SPICE data sets formally ingested in NASA’s Planetary Data System. Users can select these data sets by simply picking them from the WGCs kernel set menu. Users can also load into WGC any kernels available on the NAIF server, including operational kernels for many missions, but it has to be done manually, which is more time consuming and requires some knowledge of kernel naming schemas and contents.
WGC can be deployed on any computer that has Java, Apache Tomcat web server, and MySQL Community Server. While NAIF does not plan to make the WGC software available to the general public, it might make the WGC binary war file together with installation and kernel database configuration instructions available to organizations involved in planetary exploration, with significant experience with SPICE and a clear need to manage their own kernel sets used by WGC.
| Applicant type | First author |
|---|
Primary author
Boris Semenov
(NASA/JPL)
Co-authors
Charles Acton
(Caltech/Jet Propulsion Laboratory)
Edward Wright
(Caltech/Jet Propulsion Laboratory)
Mark Rose
(NASA/Ames Research Center)
Nathaniel Bachman
(Caltech/Jet Propulsion Laboratory)
