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Bin start and stop

START, STOP

No differences, by definition.

Spacecraft position in ECI coordiantes (x,y,z)

SC_POSITION array

The differences in a very small number of bins are most probably due to Reason 1 above.

Ground point latitude and longitude

LAT_GEO, LON_GEO

Reason 1.

Spacecraft altitude

RAD_GEO

Reason 1.

Zenith direction

RA_ZENITH, DEC_ZENITH

McIlwain coordinates

L_MCILWAIN, B_MCILWAIN

Geomagnetic latitude

GEOMAG_LAT

16 percent of the time bins are in the underflow bin of the histogram. This is due to a known issue: on Feb. 2, 2010 we changed the quantity from unsigned to signed. Thus, all old FT2 files produced before that date have a always-positive GEOMAG_LAT, while the reprocessed ones have it signed from the beginning of the mission.

South Atlantic Anomaly flag

IN_SAA

Z-axis direction

RA_SCZ, DEC_SCZ

Reason 1.

X-axis direction

RA_SCX, DEC_SCX

Reason 1.

Orbital Pole direction

RA_NPOLE, DEC_NPOLE

Here there are considerable differences, because the new code compute the coordinates of the Orbital Pole in a different way respect to the old one. If v_i is the position vector for the i-th bin in the FT2 file, the old code computed the orbital pole vector for the i-th bin as the cross product between v_i-1 and v_i, while the new code uses the product v_i cross v_i+1. Thus basically I should compare each i-th entry in the new set with the (i+1)th entry in the old one, to obtain the same results. I don't understand why the differences are basically only in the RA, though.

Rocking angle

ROCK_ANGLE

Reason 1.

LAT GNC mode

LAT_MODE

LAT Configuration

LAT_CONFIG

Data quality flag

DATA_QUAL

Need to check why there are these differences in a couple of runs. I suspect those are BAD runs, or runs with the new values for the DQM flag.

Attitude quaternion

QSJ_1,QSJ_2,QSJ_3,QSJ_4

Reason 1.

Live time

LIVETIME

Differences are due to the bug already found in the old FT2 code. See below.