#### STEREO Level 1 Magnetometer Data

##### Coordinate Systems

The server provides both RTN coordinates and spacecraft coordinates.
RTN is defined with R from the center of the Sun to STEREO.
T is along the cross product of the Sun's rotation axis and the R direction
so that T is roughly in the direction of planetary motion. N is along the R
cross T direction, roughly northward so that the R-N plane contains the Sun's
rotation axis. Spacecraft coordinates are defined with X toward the Sun (opposite
R of RTN). Y and Z are along the spacecraft Y and Z directions which are oriented
to optimize Earth communication and hence the coordinates systems may be oriented
in quite different directions on the two observatories.

##### Data Resolution

Three data resolutions are provided in the Level 1 data: 1 Hz, 8 Hz, and 32 Hz
burst mode. The 1Hz data is created from the 125ms data by overlapped averages. The
averaged total field is also averaged from the high resolution total field and not
from the averaged components. The 32 Hz data is not continuous.

##### Data Availability

Data are available in spacecraft and RTN coordinates beginning November 7, 2006.
Since data must be first consolidated during a one month interval and processing
is performed one month at a time, data availability is normally two to three months
behind real time. If data are needed more rapidly, please use the beacon data that
come to Earth and are made available in real time.
Due to the strain on our system, you may only request up to
a month of 1Hz data or 7 days of 8Hz or 32Hz data at a time.

**Latest available data**: 2020 Nov 02 00:00:00 UTC (STEREO A),
2014 Sep 28 00:00:00 UTC (STEREO B)