2.0.0 spase://VHO/NumericalData/STEREO-A/Ephemeris/GEI_PT05M STEREO-A Ephemeris STEREO-A Positions 2009-05-20T19:08:29Z STEREO atttitude and orbit data are distributed as SPICE kernels. Since most SEP investigators would rather not deal with SPICE kernels, Caltech provides text files containing position data for the two STEREO spacecraft, in the following coordinate systems: GEI, GSE, GSM, HCI, HEE, HEEQ. spase://SMWG/Person/Janet.G.Luhmann PrincipalInvestigator spase://SMWG/Person/Andrew.J.Davis DataProducer Pointing and Orbit Data for the SEP Instruments on the STEREO Spacecraft ftp://mussel.srl.caltech.edu/pub/stereo/Position/SEP_Attitude_Orbit.pdf This document provides information about orientation of the LET instrument on the STEREO Ahead and Behind spacecraft, and instructions for calculating pointing (attitude) and position vectors for any SEP instrument from the spacecraft ancillary data. spase://SMWG/Repository/STEREO/AttitudeOrbit Online Open STEREO Attitude and Orbit Data http://www.srl.caltech.edu/STEREO/attorb.html Predicted or definitive STEREO attitude and orbit data are generated from SPICE kernels and offered in various coordinate system. Text None Calibrated spase://SMWG/Instrument/STEREO-A/Ephemeris Ephemeris 2006-10-27T00:00:00Z -P61D PT05M Heliosphere.NearEarth Heliosphere.Inner Earth.Magnetosheath These data are produced at Caltech for the benefit of SEP instrument suite investigators. The data are not currently officially "blessed" by the larger STEREO team. The time cadence of records within data files is variable. A new record is appended only at the beginning of each day, or if the position of the S/C changes by more than TOL kilometers from the previous position. TOL is currently set to 5000 km. However, the position is only sampled every 5 minutes, so for some coordinate systems the position resolution is less than 5000 km. The daily updating of these data goes 61 days into the future, and 20 days into the past. This is usually sufficient to ensure that all the data in the files eventually get promoted form "predicted" to "definitive". Occasionally, the data are manually checked to make sure that this is all working as expected. Year Column 1 The year of the data point Temporal DOY Column 2 The day of year of the data point Temporal Second Column 3 The second of the day of the data point Temporal Flag Column 4 0 if the data are predictive and 1 if the data are definitive Other X Column 5 The X component of the spacecraft position vector km 1e3>m Cartesian GEI Positional Y Column 6 The Y component of the spacecraft position vector km 1e3>m Cartesian GEI Positional Z Column 7 The Z component of the spacecraft position vector km 1e3>m Cartesian GEI Positional