As the SDO orbit perigee is raised, the particle counts for EVE’s photodiode are decreasing. This image shows a view of SDO’s orbit; the ellipses indicate how the perigee altitude is increasing after AMF 1, 2B, and 3 orbit raising burns. The color represents the EVE Lyman-alpha photodiode signal level – red being about 300 counts and blue being very low signal. The EVE photodiode counts are increasingly smaller as the perigee is raised. Once the SDO orbit is circular in a couple of weeks, we’ll be ready to finish activating the EVE detectors and start taking solar data. Thanks to Chris Jeppesen for this image of EVE’s photodiode data taken since EVE was powered on February 18.
SDO EVE mapping out inner Van Allen Radiation Belt
published February 24, 2010