LASCO Level-1 Processing Pipeline and Calibration:

Status & Overview

NBR

2010/11/03

Software Status

Top level procedure is operational and part of SolarSoft.
Works for C2 and C3 only.
Not applicable to sub-fields.

Calibration Steps Applied to Image

(In red applies to C3 only)

Subtract bias
Divide by (corrected) exposure time
Apply "fuzzy logic" to replace missing blocks
Multiply by calibration factor
Multiply by (inverse) vignetting function/array
Subtract stray light
Distortion correction
Multiply by (distortion corrected) mask of occulter/pylon/outer edge and missing blocks if > 17
Rectify image to solar north up, if SOHO in upside-down position

Information on effects of scaling images to integers, the distortion correction, and masking missing blocks.

REDUCE_LEVEL_1.PRO Sub-procedures and Source Files

Key: ( C3 only ) ( Header info. only ) ( [ C2 values] )

c3[2]_calibrate.pro

get_exp_factor.pro

offset_bias.pro

c3[2]_calfactor.pro

0.00503 [0.0286]

get_cal_name.pro

C3clearvig_nrl.fts [inv_vigc2_512506.fts]

C3ramp.fts

3m_clcl_all.fts

fuzzy_image.pro

c3[2]_warp.pro

occltr_cntr.pro

516.284, 529.489 [512.634,505.293]

get_sec_pixel.pro

subtense.pro

56.0 [11.9] arcsec/pixel

c3[2]_distortion.pro

distortion_coeffs.pro

warp_tri.pro

get_cal_name.pro

c3clearmask3.fts

c3[2]nullblocks.sav

adjust_hdr_tcr.pro

adjust_all_date_obs.pro

time_correction.pro

If before 1997/12/30 use c2_MMDDYYtHHMM_MMDDYYtHHMM_timeoffsets.sav
Else use TIME_DIFF.DAT (EIT packet time offsets)

c3[2]_pre(post)_recovery_adj_xyr_medv2.sav

get_solar_radius.pro

sohoephem.pro

reduce_statistics2.pro