LASCO Data Products

NOTE: See retrieval policies for the acknowledgement to be used when using these data products.
The NRL LASCO Library of IDL procedures is available through the SolarSoft Library.

Image Files

Level 0.5 decompressed image files (FITS format) are available through the LASCO online database
Level 1 calibrated image files

These can be downloaded through the LASCO online database by selecting "level-1" as the file type. Note that this archive often stays up to 12-months behind realtime in order for us to ensure that the data product has the very best calibrations available. If you need more recent data as a level-1 product, you can contact us and we will do all we can to assist you.

Level 2 calibrated image files

Polarized - For most of the mission, there is one polarizer sequence taken each day in each telescope. These are used to generate Percent Polarized (%P) and Polarized Brightness (PB) images. These are half-resolution (512x512) images with the best available calibration available at the time of processing applied. This product is produced as part of the regular (daily) data processing stream. For access to these data, please contact the lasco webmaster.
Color - There are a few times when color sequences are taken which can be combined to create color images. For details, please contact us.
C1 on/offline images - The Fabry-Perot interferometer on the C1 telescope allows images to be taken at very narrow bandpasses at discrete wavelengths. Images of the corona at certain "emission lines" can be derived by combining images taken on the line and off the line. Please direct further questions to R. Schwenn.
To obtain any of this data as a level-2 product, we ask that you contact us directly.

Daily Movies (1/2 resolution)

The daily movies are byte scaled image sequences in MPEG format on the web and in MVI format at NRL.

Real-time Images and Movies

Daily Images

Daily images are available from the SOHO archive.

Carrington Maps

Intensity maps for east limb and west limb data showing the large-scale solar corona as 27 day (1 rotation) views. They are available by rotation as GIF and postscript files or by individual maps in FITS format. For an explanation of these Carrington Maps, click here.

Background Models

We have developed background models that are used to remove the static K-corona, F-corona, and stray light from the images. These images have been created by taking the minimum over a 4 week period of daily median images. Several of the LASCO IDL library routines use background images to enhance the level 0.5 image. The monthly minimum images are available here and also through the SolarSoft Database. Normally, you will only need the two monthly minimum images which bracket the date you are interested in. The correct background image is retrieved using getbkgimg.pro in the LASCO IDL Library. A more detailed explanation of filenames can be found here for nominal monthly images. For selected roll periods (such as late 1998 and early 1999) there are special rolled backgrounds.

Coronal Mass Ejections

Comets

For all SOHO comet information, inlcuding lists of discoveries, discoverers and how anyone can search for the SOHO comets, see the Sungrazer pages.

Debris

The LASCO cameras have recorded many "streaks" across the CCDs of varying brightness, length and character. These are intrepreted to be dust particle(s) or other debris passing in front of the telescope during an exposure.

Debris List
Debris images: These GIF files display two versions of the same image side-by-side. On the left is a ratio of the image with the monthly median/k-corona model image. It is best for looking at details of bright streaks. You will also find the telescope, time and name of the original file printed along the bottom. On the right is a difference of the image and the previous image. The mask over the occulter and around the edges has been omitted. These are best for seeing faint streaks.