LASCO and EIT
Introduction
Summary of LASCO/EIT
What is LASCO?
What is EIT? (external link)
FAQ

Real Time Data Products
Realtime Images
RealTime Movies (SOHO Movie Theater)

Archive Data Products
Download LASCO Data
Carrington Maps
Data Products
Image Gallery
Movie Gallery
Processing Levels
FITS Header Keywords
Data Policy
Wavelet images/movies

Science Information
Coronal Mass Ejections
Eclipse Observations
LASCO Calibration
LASCO C3 Planet transits (via Sungrazer)

Technical
Team and Operations
Resources
LASCO/C1 at MPAe (Germany)
LASCO at LAS (France)
LASCO Handbook
Technical Notes
Detailed Documentation
Acronyms

Related Links
Solwind Images and CMEs
SOHO Home page
SOHO and SOHO Instruments
Other Solar Satellites and Observatories

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

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