EGSO WP5

      Solar  Features  Catalogue (SFC)

                                                                                     

Text Box: 	The current SFC represents the 4 month (April-July ’02) data of detected Solar Features (Sunspots, Active Regions and Filaments).  

	In the future the SFC is to be populated with the data covering a longer period starting from the SOHO era in 1995. 


	The catalogue holds the details of all detected features and their parameters, such as: the center of gravity in pixel and heliographic coordinates; minimum, maximum and mean intensity; area in square degrees and dimensions in pixels; contrast ratios; a chain-code or raster scan representation of the feature boundary etc. (see the document for features parameters organization and description).  

	Please provide us with some feedback and comments onto the following issues:

1) Is there enough information for data use in your research?
2) What information do you use regularly?
3) Is there anything you don't use, or don't use often?
4) Did you find the SFC usage is straightforward and easy? If not, please, provide your suggestions how to improve it.

Please email any suggestions to FR-EGSO@Bradford.ac.uk

In the nearest future we are planning to publish here an online multiple choice questionnaire on each feature for your comments.
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 Download the SFC hitchhiker's guide as a .doc file

If you ready you can start the SFC search Go to SFC ,

otherwise please read the following Features Parameters

Organization and Description:

 

Please click over the required link from the following Table of Contents:

[All Underlined words have a hyperlink] 

I. General organization-- 3

1.1  Definitions- 3

1.2. Practical organization-- 4

II. Database organization-- 5

2.1. Philosophy of the organization-- 5

2.2. Database structure- 5

2.3. Description of the tables- 6

2.3.1. Observatory table- 6

2.3.2.  Observation table- 6

2.3.3.  Pre Processing Information Table- 7

2.3.4.  Pre Processing Setup- 7

2.3.5.  Pre Processing Output Table- 7

2.3.6.  Feature Recognition Code Info Table- 7

2.3.7.  Feature Tables- 8

III. Keywords description-- 8

3.1. Observatory (Instrument) Table- 8

3.2. Observation Table- 9

3.3. PreProcessing_Info Table- 9

3.4. PreProcessing_Setup Table- 10

3.5. Processed Observation Table (can be split into separate tables) 10

3.6. FRC_Info Table- 11

3.7. Features description-- 11

3.7.1. Sunspots- 11

3.7.2.  Active regions- 12

3.7.3.  Filaments- 13

IV.  Feature recognition parameters- 14

V. Input files description – sample- 17

5.1. Active Regions- 17

5.1.1. Observation Table  (xxxx_AR_Observation_Table_yyyymm.txt, CaIIK3_AR_Observation_Table_200204.txt) 17

5.1.2. Processed Observation Table (xxxx_AR_Processed_yyyymm.txt , CaIIK3_AR_Processed_200204.txt) 19

5.1.3. Detected Active Regions description (xxxx_AR_yyyymm.txt, CaIIK3_AR_200204.txt) 19

5.2. Filaments- 21

5.3.1. Observation Table  (Ha_FIL_Observation_Table_200204.txt) 22

5.3.2. Processed Observation Table ( Ha_FIL_Processed_200204.txt) 23

 

                                                                     Go to top or Go to SFC

I. General organization

1.1  Definitions

The process of automatic Solar features recognition can be roughly separated in the two main steps:

  • Cleaning the original solar image, leading to what is called a ‘pre-processed’/’cleaned’/’pre-processed’ image
  • Features recognition itself on this pre-processed image.

 

In this document, the following definitions are used to describe the various elements of the whole process:

 

  • Initial observation: This are the raw images obtained from an observatory’s database/archive, on which the whole process will be applied.
  • Cleaning code: This is the code which corrects the image faults (in term of the processing used here) of the initial observation, leading to pre-processed images.
  • Pre-processing: This is the step corresponding to the cleaning code usage.
  • Pre-processed observation: This is the image after the cleaning code application. In this image, the Sun is circular, centered on the image and scaled to the standard dimensions (1024x1024 for the full image), limb darkening is corrected in the case of spectroheliograms, and observational faults are corrected (such as intensity fluctuations due to clouds, strips due to dust on the slit, etc). As long as the working database will be in a test mode, the pre-processed images will be kept in order to quickly re-process them, if required.
  • Chain code (CC): This is a description of the feature boundary (active regions), or the feature area (sunspots), or the part of it (such as skeleton in the case of filaments). A CC starting point is given (it could be in pixels or arcsecond) with set of directions indicated by numbers 0 to 7 as defined in Fig. 3. With these CC values and the spatial resolution of a pixel,  the shape of the feature structure can be over-imposed onto any full solar disk image.
  • Skeleton: In the case of filaments, a skeleton is the line following the central elongation of the filament. It is expressed as a chain code above.
  • Rectangular image (Bounding rectangular): is a rectangular bounded area of the pre-processed image that contains a full detected feature with its pixel values.
  • Gravity Center: The centre of gravity is the average location of the weight of features.
  • Skeleton center: The middle point of a filament skeleton
  • Pixel origin: A starting position (0,0) for counting pixels up from the bottom left corner by rows as shown in Fig. 1.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Fig. 1: Images dimensions and origin location

                                                                              Go to top or Go to SFC

                                                                                             

 

1.2. Practical organization

The original images are pre-processed and used for feature detection. Every complete process will lead to a set of files (mostly ASCII files, see IV for their complete description). Hence, there will be a set of a few files for every observing day. This set will be destroyed as soon as the data are included in the Solar Feature Catalogue (but not during the test period).

If several initial observations are processed for one day, there will be as many sets of files as the initial observations. For each kind of files of the general set, an IDL code is available to read it.

II. Database organization

2.1. Philosophy of the organization

The original observations are subject to various distortions in shape and intensity some of which are corrected at the pre-processing stage using the cleaning code. The cleaning code setup is stored in the database in a way that is described below in section 2.2. Hence, for every initial observation (original image) there is one corresponding pre-processed observation.

Every pre-processed observation has one or a few features detected on it and, therefore, a few feature-related parameters can be associated with a single pre-processed observation.

The following features are detected on a pre-processed image: sunspots, active regions and filaments. The detection is performed on a cleaned (pre-processed) observation and the results of detection are related to this pre-processed observation. The setup parameters of a pre-processed image are stored in the database that allows to repeat the pre-processing operations on an original image.. 

2.2. Database structure

In the Feature link table shown in Fig 2, the Ref pre-processed 1 corresponds to the observations that has been used for the primary extraction of the feature. Ref pre-processed 2 and 3 correspond to other files (if any) that have been used to improve the FR.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


                                                                                              Go to top or Go to SFC

                                                                                             

 

 

2.3. Description of the tables

At this time, nine database tables are identified. For a description of the keywords, refer to section III (Keywords description). By default, the fields of the tables correspond to the corresponding subsection of section III. If this is not the case, it is specified hereafter.

 

2.3.1. Observatory table

Name: OBSERVATORY

Description: This table contains all useful information concerning the observatory/telescope/instrument

Keywords: OBSERVAT, INSTRUME, TELESCOP, BITPIX, UNITS, WAVELNTH, WAVELNTH_NAME, WAVELNTH_UNIT, OBS_TYP

See section 3.1

 

2.3.2.  Observation table

Name: OBSERVATIONS

Description: This table contains all the useful information concerning the original image.

Keywords: OBSERVAT_ID, DATE-OBS, DATE-END, JDINT, JDFRAC, EXPTIME, CARROT, BSCALE, BZERO, NAXIS1, NAXIS2, R_SUN, CENTER_X, CENTER_Y, CDELT1, CDELT2, QUALITY, FILENAME, COMMENT

See section 3.2

2.3.3.  Pre Processing Information Table

Name: PP_INFO

Description: This table contains the information related to the cleaning code and who run it.

Keywords: INSTITUT, CODE, VERSION, CONTACT

See section 3.3

 

2.3.4.  Pre Processing Setup

Name: PP_SETUP

Description: This table contains the information related to the cleaning code setup – describing the algorithm and the adjustable parameters listed in the normalization processing. These parameters along with version and name from pp_info table is sufficient to rerun the code to obtain the pre-processed image.

Keywords: EFIT, STANDARD, LIMBDARK, BACKGROUND, LINECLEAN, QSUN_INT_PRO, PERCENT, NAXIS1, NAXIS2, CENTER_X, CENTER_Y, R_SUN, DIVISION, INORM

See section 3.4

2.3.5.  Pre Processing Output Table

Name: PP_OUTPUT

Description: This table contains the values amended, extracted during the pre-processing stage

Keywords:  PP_INFO_ID, PP_SETUP_ID, OBSERVATION_ID, RUN_DATE, EL_CEN_X, EL_CEN_Y, EL_AXIS1, EL_AXIS2, EL_ANGLE, STDEV, STDEVGEO, ALGERR, CDELT1, CDELT2, BITPIX, QSUN_INT, LOC_FILE

See section 3.5

 

2.3.6.  Feature Recognition Code Info Table

Name: FRC_INFO

Description: Similar to PP_INFO, this table contains information about different versions of feature recognition codes and people responsible for running it.

Keywords:  INSTITUT,  CODE,  VERSION,  FEATURE_NAME, CONTACT

See section 3.6

 

2.3.7.  Feature Tables

            (Sunspots, Active Regions, Filaments)

 

Description: This table contains all the parameters describing the detected feature. There is one table entry for one feature.

Note: If necessary, this table could be split into as many tables as the kind of features detected. But this will affect the use of the FEAT_LINK and PARAM_FEAT tables.

Keywords:  FR_CODE_INFO_ID, PROCES_OBS_ID, RUN_DATE, GC_ARC_X, GC_ARC_Y, GC_CAR_LAT, GC_CAR_LON, FEAT_NPIX, FEAT_AREA, FEAT_MEAN2QSUN, BR_ARC (BR_ARC_X0, BR_ARC_Y0, BR_ARC_X1, BR_ARC_Y1), BR_PIX (BR_PIX_X0, BR_PIX_Y0, BR_PIX_X1, BR_PIX_Y1 ), FEAT_MAX_INT, FEAT_MIN_INT, FEAT_MEAN_INT, ENC_MET

            Sunspots:          N_UMBRAS, UPIXSIZE, DIAMETER, RASTER_SCAN

            Active Regions:CC_PIX_X,  CC_PIX_Y, CC_ARC_X, CC_ARC_Y, CHAINCODE

            Filaments:          CURVATURE, ELONG, ORIENTATION, COD_SKE_PIX_X, COD_SKE_PIX_Y, COD_SKE_ARC_X,  COD_SKE_ARC_Y, CC_PIX_X,  CC_PIX_Y, 

                                          CC_ARC_X, CC_ARC_Y, CHAINCODE

(See also section 3.7.1 for sunspots, 3.7.2. for active regions, 3.7.3 for filaments)

 

                                                                               Go to top or Go to SFC

                                                                                             

 

III. Keywords description

3.1. Observatory (Instrument) Table

 

Name

Format

Description

Notes

ID

Int(11)

Index to identify file and link files together

Primary Key

OBSERVAT

Varchar(255)

Name of the observatory that made the observation

e.g. Meudon

INSTRUME

Varchar(150)

Name of the instrument that made the observation

e.g. Spectroheliograph

TELESCOP

Varchar(150)

Name of the sub-part of the instrument that made the observation

e.g. C2 in case of LASCO

UNITS

Varchar(100)

Units of the original observation intensity

e.g. counts in most cases

WAVELNTH

Float

Wavelength of the original observation (nm)

May be another keyword should be added for the unit (hard-X, optical or radio don’t use the same units: keV, nm, MHz)

WAVELNTH_NAME

Varchar(50)

Name of the wavelength of the original observation (if any)

e.g. H alpha, Ca II, Fe IX

WAVELNTH_UNIT

Int(4)

 

 

OBS_TYPE

Varchar(150)

Spectral domain in which observations were made e.g. optical, SXR, EUV

COMMENT

text

                                                                              Go to top or Go to SFC

                                                                                             

 

3.2. Observation Table

Name

Format

Description

Notes

ID

Int(11)

Primary Index

Internal use, may be used as an unique ID

OBSERVAT_ID

Int(11)

Pointing to observatory, wavelength etc

 

DATE-OBS

Datetime

Date and time of the start of the observation in UTC

e.g. 2003-10-01T17:15:32.123

DATE-END

Datetime

Date and time of the end of the observation in UTC

Same format as above

JDINT

Int(11)

Julian day of the observation, integer part

Internal use

JDFRAC

Double

Julian day of the observation, fraction part

Internal use

EXPTIME

Float

Exposure time (if available), in seconds and fractions of s

 

CARROT

Int(7)

Carrington rotation

Must be calculated from DATE_OBS

BSCALE

Double

As extracted from the header

 

BZERO

Double

As extracted from the header

 

BITPIX

Int(3)

Coding of the original image

 

NAXIS1

Int(6)

First dimension of the original image (X)

 

NAXIS2

Int(6)

Second dimension of the original image (Y)

 

R_SUN

Double(10,5)

Radius of the Sun, in pixels

(as extracted from the Header)

CENTER_X

Double(10,5)

Coordinate of Sun centre in X, in pixels

(as extracted from the Header)

CENTER_Y

Double(10,5)

Coordinate of Sun centre in Y, in pixels

(as extracted from the Header)

CDELT1

Double

Spatial scale of the original observation (X axis) (in arcsec)

 

CDELT2

Double

Spatial scale of the original observation (Y axis) (in arcsec)

 

QUALITY

Varchar(20)

Quality of the original image (in terms of processing)

Has to be defined

FILENAME

Varchar(100)

Name of the original file

Path is useful for some MDI files

DATA_OBS_STRING

Varchar(150)

DATA_END_STRING

Varchar(150)

LOC_FILENAME

Varchar(200)

ID2

Int(11)

COMMENT

String

As extracted from the Header

 

 

                                                                              Go to top or Go to SFC

                                                                                             

 

3.3. PreProcessing_Info Table

 

ID

Int(11)

Primary Index

Internal use, may be used as an unique ID

INSTITUT

Varchar(150)

Institute responsible for running the cleaning code

e.g. Bradford, Meudon

CODE

Varchar(150)

Name of the cleaning code

 

VERSION

Varchar(50)

Version of the cleaning code

 

CONTACT

Varchar(150)

Person responsible for running cleaning code

 

 

3.4. PreProcessing_Setup Table

Name

Format

Description

Notes

ID

Int(11)

Primary Index

Internal use, may be used as an unique ID

EFIT

tinyint(1)

Has ellipse fitting been used

Yes or No

STANDARD

tinyint(1)

Has standardisation been used

Yes or No

LIMBDARK

tinyint(1)

Has limb darkening removal been used

Yes or No

BACKGROUND

tinyint(1)

Has background cleaning been performed

Yes or No

LINECLEAN

tinyint(1)

Has line cleaning been used

Yes or No

QSUN_INT_PRO

tinyint(1)

Was Quiet Sun Intensity determined

Yes or No

PERCENT

Float

Used in EllipseFitting

Default = 0.5

NAXIS1

Int(8)

First dimension of the pre-processed image (X)

 

NAXIS2

Int(8)

Second dimension of the pre-processed image (Y)

 

CENTER_X

Float

Coordinate of Sun centre in X, in pixels

 

CENTER_Y

Float

Coordinate of Sun centre in Y, in pixels

 

R_SUN

Float

Radius of the Sun, in pixels

 

DIVISION

tinyint(1)

Method used to contrast image

Yes or No

INORM

Float

Normalizing parameter for division method

Optional

 

                                                                               Go to top or Go to SFC

                                                                                             

 

3.5. Processed Observation Table (can be split into separate tables)

Name

Format

Description

Notes

ID

Int(11)

Primary Index

Internal use, may be used as an unique ID

PP_INFO_ID

Int(6)

Pointing to information about Pre-Processing code, version, institute

 

PP_SETUP_ID

Int(6)

Pointing to information about Preprocessing setup

 

OBSERVATION_ID

Int(11)

Pointing to Observation

 

RUN_DATE

datetime

Date where the PP code was run

 

LOC_FILE

Varchar(100)

Name of the pre-processed file, including the path from the local organization

 

EL_CEN_X

Double

Ellipse centre coordinate, X axis (in pixels)

0 if no ellipse fitting used

EL_CEN_Y

Double

Ellipse centre coordinate, Y axis (in pixels)

 

EL_AXIS1

Double

Ellipse long axis (in pixels)

 

EL_AXIS2

Double

Ellipse short axis (in pixels)

 

EL_ANGLE

Double

Ellipse angle (°)

 

STDEV

Double

Standard deviation(in pixels)

 

STDEVGEO

Double

Standard deviation geometric(in pixels)

 

ALGERR

Double

Algebraic error (in pixels)

 

CDELT1

Double

Spatial scale of the pre-processed observation (X axis) (in arcsec)

Calculated based on standardization params

CDELT2

Double

Spatial scale of the pre-processed observation (Y axis) (in arcsec)

 

BITPIX

Int(3)

Coding of the pre-processed image

Changes if line cleaning is used

QSUN_INT

Float

Quiet Sun value estimated after pre-processing

RUN_DATE

datetime

PR_LOCFNAME

Varchar(150)

ORG_FNAME

Varchar(150)

ID_ASCII

Int(11)

 

                                                                              Go to top or Go to SFC

                                                                                             

 

3.6. FRC_Info Table

ID

Int(11)

Primary Index

Internal use, may be used as an unique ID

INSTITUT

Varchar(150)

Institute responsible for running the FR code

e.g. Bradford, Meudon

CODE

Varchar(100)

Name of the FR code

 

VERSION

Varchar(50)

Version of the FR code

 

FEATURE_NAME

Varchar(100)

Features Detected

e.g. Sunspot

CONTACT

Varchar(150)

Person responsible for running FR code

 

3.7. Features description

3.7.1. Sunspots

Name

Format

Description

Notes

ID

Int(11)

Index to recognize file and link files together

Internal use, may be used as an unique ID

FRC_INFO_ID

Int(4)

Reference to FR code information

 

PROCD_OBS

Int(11)

Reference to Processed Observation where detec. Was made

 

RUN_DATE

datetime

Date when FR code was run

 

GC_ARC_X

Double

Gravity centre in latitude X (arcsec)

 

GC_ARC_Y

Double

Gravity centre in longitude Y (arcsec)

 

GC_CAR_LAT

Double

Gravity centre in heliographic (°)

 

GC_CAR_LON

Double

Gravity centre in heliographic (°)

 

FEAT_NPIX

Int(11)

Number of pixels included in the feature

 

FEAT_AREA

Double

Area of the feature, in degrees2

 

FEAT_MEAN2QSUN

Double

Mean of the feature to QS intensity ratio

 

BR_ARC

Double

Bounding rectangle coordinates, in arcsec

From lower left to upper right: Xll, Yll, Xur, Yur; (BR_ARC_X0, BR_ARC_Y0, BR_ARC_X1, BR_ARC_Y1)

BR_PIX

Int(8)

Bounding rectangle coordinates in pixels

Same as above; (BR_PIX_X0, BR_PIX_Y0, BR_PIX_X1, BR_PIX_Y1)

FEAT_MAX_INT

Float

Feature maximum value, in units of the original obs.

As in UNITS

FEAT_MIN_INT

Float

Feature minimum value, in units of the original obs.

As in UNITS

FEAT_MEAN_INT

Float

Feature mean intensity value, in units of the original obs.

As in UNITS

ENC_MET

Varchar(50)

Encoding method (Raster)

e.g. raster, chain code, None… TBC

RASTER_SCAN

text

 

 

N_UMBRAS

Int(4)

Number of umbras

 

UPIXSIZE

Int(11)

Umbra area in pixels

 

DIAMETER

Double

Diameter of the sunspot in degrees

 

RSCAN_LENGTH

Int(6)

PR_LOCFNAME

Varchar(150)

TOTALFLUX

Float

ABSTOTALFLUX

Float

MAXFLUX

Float

MINFLUX

Float

TOTAL_UFLUX

Float

ABSTOTAL_UFLUX

Float

MAX_UFLUX

Float

MIN_UFLUX

Float

ID_OBS

Int(4)

ID

Int(11)

 

 

  

                                                                            Go to top or Go to SFC

                                                                                             

 

3.7.2.  Active regions

Name

Format

Description

Notes

ID

Int(11)

Index to identify file and link files together

Internal use, may be used as an unique ID

FRC_INFO_ID

Int(4)

Reference to FR code information

 

PROCD_OBS

Int(11)

Reference to Processed Observation where detec. Was made

 

RUN_DATE

datetime

Date when FR code was run

 

GC_ARC_X

Double

Gravity centre in latitude X (arcsec)

 

GC_ARC_Y

Double

Gravity centre in longitude Y (arcsec)

 

GC_CAR_LAT

Double

Gravity centre in heliographic (°)

 

GC_CAR_LON

Double

Gravity centre in heliographic (°)

 

FEAT_NPIX

Int(11)

Number of pixels included in the feature

 

FEAT_AREA

Double

Area of the feature, in degrees2

 

FEAT_MEAN2QSUN

Double

Mean of the feature to QS intensity ratio

 

BR_ARC

Double

Bounding rectangle coordinates, in arcsec

From lower left to upper right: Xll, Yll, Xur, Yur; (BR_ARC_X0, BR_ARC_Y0, BR_ARC_X1, BR_ARC_Y1)

BR_PIX

 

Int(8)

Bounding rectangle coordinates in pixels

As above; (BR_PIX_X0, BR_PIX_Y0, BR_PIX_X1, BR_PIX_Y1)

FEAT_MAX_INT

Float

Feature maximum value, in units of the original obs.

As in UNITS

FEAT_MIN_INT

Float

Feature minimum value, in units of the original obs.

As in UNITS

FEAT_MEAN_INT

Float

Feature mean intensity value, in units of the original obs.

As in UNITS

ENC_MET

Varchar(50)

Encoding method

e.g. raster, chain code, None… TBC

CC_PIX_X

Int(8)

Coding 1st position in pixels, X axis

To Be Confirmed

CC_PIX_Y

Int(8)

Coding 1st position in pixels, Y axis

TBC

CC_ARC_X

Float

Coding 1st position in arcsec, X axis

TBC

CC_ARC_Y

Float

Coding 1st position in arcsec, Y axis

TBC

CHAIN_CODE

text

       
       
   

                                                                              Go to top or Go to SFC

                                                                                             

 

3.7.3.  Filaments

Name

Format

Description

Notes

ID

Int(11)

Index to identify file and link files together

Internal use, may be used as an unique ID

FRC_INFO_ID

Int(4)

Reference to FR code information

 

PROCD_OBS_ID

Int(11)

Reference to Processed Observation where detect. Was made

 

RUN_DATE

Datetime

Date when FR code was run

 

SC_ARC_X

Double

Skeleton centre X in arcsec

 

SC_ARC_Y

Double

Skeleton centre Y in arcsec

 

SC_CAR_LAT

Double

Skeleton centre in Carrington coordinate  (°)

 

SC_CAR_LON

Double

Skeleton centre in Carrington coordinate (°)

 

FEAT_NPIX

Int(11)

Number of pixels included in the feature

 

FEAT_AREA

Double

Area of the feature, in degrees2

 

FEAT_MEAN2QSUN

Double

Mean of the feature to QS intensity ratio

 

BR_ARC

Double

Bounding rectangle coordinates, in arcsec

From lower left to upper right: Xll, Yll, Xur, Yur ; (BR_ARC_X0, BR_ARC_Y0, BR_ARC_X1, BR_ARC_Y1)

BR_PIX

Int(8)

Bounding rectangle coordinates in pixels

As above; (BR_PIX_X0, BR_PIX_Y0, BR_PIX_X1, BR_PIX_Y1)

FEAT_MAX_INT

Float

Feature maximum value, in units of the original obs.

As in UNITS

FEAT_MIN_INT

Float

Feature minimum value, in units of the original obs.

As in UNITS

FEAT_MEAN_INT

Float

Feature mean intensity value, in units of the original obs.

As in UNITS

ENC_MET

Varchar(50)

Encoding method

e.g. raster, chain code, None… TBC

CC_PIX_X

Int(8)

Coding 1st position in pixels, X axis

To Be Confirmed

CC_PIX_Y

Int(8)

Coding 1st position in pixels, Y axis

TBC

CC_ARC_X

Float

Coding 1st position in arcsec, X axis

TBC

CC_ARC_Y

Float

Coding 1st position in arcsec, Y axis

TBC

SKE_LEN_DEG

Float

Length of the filament in degrees

 

CURVATURE

 Float

Index of curvature of the skeleton

 

ELONG

Float

Elongation factor

=area/(2d)2 where d=thickness

ORIENTATION

 Float

Orientation of the filament

 

COD_SKE_PIX_X

Int(8)

Skeleton chain code 1st position, in pixels, X axis

 

COD_SKE_PIX_Y

Int(8)

Skeleton chain code 1st position, in pixels, Y axis

 

COD_SKE_ARC_X

Float

Skeleton chain code 1st position, in arcsec (latitude)

 

COD_SKE_ARC_Y

Float

Skeleton chain code 1st position, in arcsec (longitude)

 

CHAIN_CODE

text

Boundary chain code

 

CHAIN_CODE_SKE

text

Skeleton chain code

CCODE_LNTH

Int(11)

CCODE_SKE_LNTH

Int(11)

 

                                                                              Go to top or Go to SFC

                                                                                             

           

IV.  Feature recognition parameters

(Including the definitions of some of the fields in the tables above)

 

Observatory and Observation tables – most of the fields are inherited from the fits-file headers.  However, Carrington Rotation field will be calculated (via SolarSoft routines), if not available in the header. Some of the Observatory table entries are entered manually based on the information available at the observatory web-site.

 

PP Info, FRC Info and PP Setup Tables – keyword descriptions self-explanatory.

 

PP Output Table:

Ellipse center (EL_CEN_X & EL_CEN_Y)  is calculate in IDL coordinates ( (0, 0) corresponding to bottom left corner of the image)

Ellipse Angle is the angle between long axis and E->W axis

Ellipse fit errors (STDEV, STDEVGEO, ALGERR) are calculated based on the extracted limb and the fitted ellipse.

As Standardization procedure normalizes image to a given radius, CDELT1, CDELT2 depend on the date of the observation and have to be calculated for the pre-processed image.

BITPIX value is affected when Background cleaning procedure is used

Quiet Sun Intensity (QSUN_INT) is estimated/defined as the most popular intensity value (histogram maximum) in a pre-processed (flat) image.

 

 

Feature tables:

 

 Sunspots

  • FEAT_AREA & DIAMETER are calculated by mapping (back projection) the detected region to heliographic plane (with length of one pixel equal to 0.1 degree by default), Diameter is defined as a maximum distance between any two points of the feature.
  • RASTER SCAN represents a scan of a bounding rectangle with pixel values equal to 0 corresponding to quiet sun, 1 to penumbra, 2 to umbra. The first/start pixel corresponds to bottom left corner of the bounding rectangle. IDL code for raster scan reconstruction is available.
  • FEAT_MEAN2QSUN, FEAT_MAX_INT, FEAT_MIN_INT, FEAT_MEAN_INT are calculated based on the detected locations and pre-processed (flat) image.

 

Active Regions:

  • FEAT_AREA is calculated by mapping (back projection) the detected region to heliographic plane (with length of one pixel equal to 0.1 degree by default)
  • BR_ARC is the bounding rectangle coordinates in arcsec for each detected region, the rectangles size are decided according to the feature size (i.e. how may pixel in the detected region). First point the lower left and second point is the upper right.
  • CHAIN_CODE represent the contour of the detected region by following the boundary around it in a counter anti-clockwise fashion, pixel by pixel, until it returns to the starting pixel. Each pixel on the boundary will be represented by a three bit binary number from 000 to 111 (0 to 7) to indicate the next pixel location.

 

 

 

 

 

 

 

 

 


Fig. 3 : Chain Code in 8-connectivity, and its derivative code: 4 4 4 6 4 6 6 0 0 1 2 0 75 6 0 2 2 2 3

 

                                                                               Go to top or Go to SFC

                                                                                             

 

Filaments:

 

  • SC_ARC_X, GC_ARC_Y: Skeleton center in Arcsecs. Given by the middle point of the filament’s skeleton.
  • SC_CAR_LAT, GC_CAR_LON: Skeleton center coordinates in Carrington.
  • FEAT_MEAN2QSUN, FEAT_MAX_INT, FEAT_MIN_INT, FEAT_MEAN_INT are calculated with the cleaned image pixel values.
  • FEAT_AREA, SKE_LEN_DEG are calculated by mapping (back projection) the detected region to heliographic plane.
  • BR_ARC is the bounding rectangle coordinates in arcsec for each detected filament. It enclose the filament skeleton which define the rectangle size.
  • CHAIN_CODE represent the contour of the detected region by following the boundary around it, pixel by pixel, until it returns to the starting pixel. Each pixel on the boundary is represented by a number (0 to 7) giving the next pixel location (see active regions).
  • CHAIN_CODE_SKE: Skeleton chain code, starting from one extremity of the skeleton and ending to the other extremity, with the same directions definition as for CHAIN_CODE.
  • COD_SKE_PIX_X, COD_SKE_PIX_Y: coordinate in pixel of the first point of the skeleton.
  • ELONG: Elongation factor of the filament: FEAT_AREA/(2d)² where ‘d’ is the thickness of the region.
  • CURVATURE: Curvature index of the filament: 10 * (1 - (distance between extremum)/length)
  • ORIENTATION: Main direction of the filament, in degrees counted clockwise from Ox.

V. Input files description – sample

The files below are produced as a query search from the SFC database by an observation date/time and instrument/wavelength which are assumed to be fixed for these files as stated in the file descriptions. In the real SFC database these data will be also incorporated into the resulting ASCII file produced for a user.

5.1. Active Regions

 

For the current db demo the following three ASCII files are produced for each month

  1. xxxx_AR_Observation_Table_yyyymm.txt (containing all the useful information concerning the original image )
  2. xxxx_AR_Processed_yyyymm.txt (containing information concerning the processed image)
  3. xxxx_AR_yyyymm.txt (containing all the parameters describing the detected ARs)

 

            xxxx used wavelength (i.e. Ca II k3, )

            AR, active regions files

            yyyy the selected year

            mm the selected month

 

            e.g.

            CaIIK3_AR_Observation_Table_200204.txt

            CaIIK3_AR_Processed_200204.txt

            CaIIK3_AR_200204.txt

                                                                               Go to top or Go to SFC

                                                                                             

 

5.1.1. Observation Table  (xxxx_AR_Observation_Table_yyyymm.txt, CaIIK3_AR_Observation_Table_200204.txt)

 

                      Sample of the CaIIK3_AR_Observation_Table_042002.txt file shows the used parameters

 

 

No

Name

Format

Description

Notes

0

INDEX

Long

Primary Index

Internal use, may be used as an unique ID

1

DATE-OBS

String

Date and time of the start of the observation in UTC

e.g. 2003-10-01T17:15:32.123

2

DATE-END

String

Date and time of the end of the observation in UTC

Same format as above

3

JDINT

Long

Julian day of the observation, integer part

Internal use

4

JDFRAC

Double

Julian day of the observation, fraction part

Internal use

5

EXPTIME

Float

Exposure time (if available), in sec. and fractions of sec.

 

6

CARROT

Integer

Carrington rotation

Must be calculated from DATE_OBS

7

BSCALE

Float

As extracted from the header

 

8

BZERO

Float

As extracted from the header

 

9

NAXIS1

Integer

First dimension of the original image (X)

 

10

NAXIS2

Integer

Second dimension of the original image (Y)

 

11

R_SUN

Float

Radius of the Sun, in pixels

(as extracted from the Header)

12

CENTER_X

Float

Coordinate of Sun centre in X, in pixels

(as extracted from the Header)

13

CENTER_Y

Float

Coordinate of Sun centre in Y, in pixels

(as extracted from the Header)

14

CDELT1

Float

Spatial scale of the original observation (X axis) (in arcsec)

 

15

CDELT2

Float

Spatial scale of the original observation (Y axis) (in arcsec)

 

16

QUALITY

TBD

Quality of the original image (in terms of processing)

Has to be defined (/N)

17

FILENAME

String

Name of the original file as in the image header

 

18

FILENAME2

String

Name and path to the original file

 

19

COMMENT

String

As extracted from the Header

 

/N means no data available for the parameter 

                                                                       Go to top or Go to SFC

                                                                                             

 

5.1.2. Processed Observation Table (xxxx_AR_Processed_yyyymm.txt , CaIIK3_AR_Processed_200204.txt)

                                              Sample of the CaIIK3 CaIIK3_AR_Processed_042002.txt file shows the used parameters

 

No

Name

Format

Description

Notes

0

INDEX

Long

Primary Index

Internal use, may be used as an unique ID

1

RUN_DATE

String

Date where the PP code was run

 

2

LOC_FILE

String

Name of the pre-processed file, including the path from the local organization

 

3

CDELT1

Float

Spatial scale of the pre-processed observation (X axis) (in arcsec)

Calculated based on standardisation parameters

4

CDELT2

Float

Spatial scale of the pre-processed observation (Y axis) (in arcsec)

 

5

QSUN_INT

Float

Quiet Sun value estimated after pre-processing

 

6

FILENAME2

String

Name of the pre-processed file, including the full path from the local organization

 

7

FILENAME2

String

Name and path to the original file

As 18 in the previous table, used to link the db tables

                                                                       Go to top or Go to SFC

                                                                                             

 

5.1.3. Detected Active Regions description (xxxx_AR_yyyymm.txt, CaIIK3_AR_200204.txt)

 

 

 

 

No

Name

Format

Description

Notes

0

GC_ARC_X

Float

Gravity centre in latitude X (arcsec)

 

1

GC_ARC_Y

Float

Gravity centre in longitude Y (arcsec)

 

2

GC_CAR_LAT

Float

Gravity centre in heliographic (°)

 

3

GC_CAR_LON

Float

Gravity centre in heliographic (°)

 

4

FEAT_NPIX

Long

Number of pixels included in the feature

 

5

FEAT_AREA

Float

Area of the feature, in degrees

 

6

FEAT_MEAN2QSUN

Float

Mean of the feature to QS intensity ratio

 

7-10

BR_ARC

Float(4)

Bounding rectangle coordinates, in arcsec

From lower left to upper right: Xll, Yll,Xur,Yur;(BR_ARC_X0,BR_ARC_Y0,BR_ARC_X1,BR_ARC_Y1)

11-14

BR_PIX

Integer(4)

Bounding rectangle coordinates in pixels

As above, (BR_PIX_X0, BR_PIX_Y0, BR_PIX_X1, BR_PIX_Y1)

15

FEAT_MAX_INT

Integer

Feature maximum value, in units of the original obs.

As in UNITS

16

FEAT_MIN_INT

Integer

Feature minimum value, in units of the original obs.

As in UNITS

17

FEAT_MEAN_INT

Float

Feature mean intensity value, in units of the original obs.

As in UNITS

18

ENC_MET

String

Encoding method

e.g. raster, chain code, None… TBC

19

CC_PIX_X

Integer

Coding 1st position in pixels, X axis

 

20

CC_PIX_Y

Integer

Coding 1st position in pixels, Y axis

 

21

CC_ARC_X

Integer

Coding 1st position in arcsec, X axis

 

22

CC_ARC_Y

Integer

Coding 1st position in arcsec, Y axis

 

23

COD_COUNT

Integer

Number of pixels included in the chain code

 

24

FILENAME2

String

Name of the pre-processed file, including the full path from the local organization

As 6 in the previous table, used to link the db tables

25

CHAIN_CODE

String

As described above

 

26

EOL

Float

-999.99, Indicating the end of one feature parameter

For db use

 

                                                                              Go to top or Go to SFC

                                                                                             

 

5.2. Filaments

For the current db demo the following three ASCII files are produced for each month :

 

1.      Ha_FIL_Observation_Table_yyyymm.txt (containing information concerning the original image )

2.      Ha_FIL_Processed_yyyymm.txt (containing information concerning the processed image)

3.      Ha_FIL_yyyymm.txt (containing all the parameters describing the detected filaments)

 

            Ha : Halpha wavelength

            mm : the selected month

            yyyy : the selected year

    

5.3.1. Observation Table  (Ha_FIL_Observation_Table_200204.txt)

Sample of the Ha_FIL_Observation_Table_200204.txt file

 

No

Name

Format

Description

Notes

1

INDEX

Long

Primary Index

Internal use

2

DATE-OBS

String

Date and time of the start of the observation in UTC

e.g. 2003-10-01T17:15:32.123

3

DATE-END

String

Date and time of the end of the observation in UTC

Same format as above

4

JDINT

Long

Julian day of the observation, integer part

calculated from DATE_OBS

5

JDFRAC

Double

Julian day of the observation, fraction part

calculated from DATE_OBS

6

EXPTIME

Float

Exposure time

As extracted from the header

7

CARROT

Integer

Carrington rotation

As in header or calculated from DATE_OBS

8

BSCALE

Float

 

As extracted from the header

9

BZERO

Float

 

As extracted from the header

10

BITPIX

Integer

Coding of the original image

As extracted from the header

11

NAXIS1

Integer

First dimension of the original image (X)

As extracted from the header

12

NAXIS2

Integer

Second dimension of the original image (Y)

As extracted from the header

13

R_SUN

Float

Radius of the Sun, in pixels

As extracted from the header

14

CENTER_X

Float

Coordinate of Sun centre in X, in pixels

As extracted from the header

15

CENTER_Y

Float

Coordinate of Sun centre in Y, in pixels

As extracted from the header

16

CDELT1

Float

Spatial scale of the original observation (X axis)

As extracted from the header

17

CDELT2

Float

Spatial scale of the original observation (Y axis)

As extracted from the header

18

QUALITY

TBD

Quality of the original image (in terms of processing)

Has to be defined (/N)

19

FILENAME

String

Name of the original file

As extracted from the header

20

LOCAL_FILENAME

String

Name and path to the original file

Internal use

21

DATE-OBS-STRING

String

Date and time of the start of the observation in UTC

Internal use

22

DATE-END-STRING

String

Date and time of the end of the observation in UTC

Internal use

23

COMMENT

String

 

As extracted from the header

 

/N means no data available for the parameter 

                                                                              Go to top or Go to SFC

                                                                                             

 

5.3.2. Processed Observation Table ( Ha_FIL_Processed_200204.txt)

Sample of the Ha_FIL_Processed_200204.txt file

 

No

Name

Format

Description

Notes

1

INDEX

Long

Primary Index

Internal use

2

RUN_DATE

String

Date when the PP code was run

 

3

LOC_FILE

String

Name of the pre-processed file, including the path from the local organization

 

4

CDELT1

Float

Spatial scale of the pre-processed observation (X axis)

Calculated based on standardisation parameters

5

CDELT2

Float

Spatial scale of the pre-processed observation (Y axis)

 

6

QSUN_INT

Float

Quiet Sun value estimated after pre-processing

 

7

LOCAL_FILENAME

String

Name and path to the original file

Internal use

8

PP_LOCAL_FILENAME

String

Name of the pre-processed file, including the full path from the local organization

Internal use

 

                                                                              Go to top or Go to SFC

                                                                                             

 

 5.3.3. Detected Filaments description (Ha_FIL_200204.txt)

 

Sample of the Ha_FIL_200204.txt file (one line)

 

 

No

Name

Format

Description

Notes

1

IND

Long

Observation index

Internal use

2

RUN_DATE

String

Date when the feature recognition code was run

 

3

GC_ARC_X

Float

Gravity centre in arcsecs (X)

 

4

GC_ARC_Y

Float

Gravity centre in arcsecs (Y)

 

5

GC_CAR_LAT

Float

Gravity centre in heliographic (°)

 

6

GC_CAR_LON

Float

Gravity centre in heliographic (°)

 

7

FEAT_NPIX

Long

Number of pixels included in the feature

 

8

FEAT_AREA

Float

Area of the feature, in square degrees

 

9

FEAT_MEAN2QSUN

Float

Mean of the feature to QS intensity ratio

 

10

BR_ARC_X0

Float

Bounding rectangle coordinates, in arcsec (x, lower left)

 

11

BR_ARC_Y0

Float

Bounding rectangle coordinates, in arcsec (y, lower left)

 

12

BR_ARC_X1

Float

Bounding rectangle coordinates, in arcsec (x, upper right)

 

13

BR_ARC_Y1

Float

Bounding rectangle coordinates, in arcsec (y, upper right)

 

14

BR_PIX_X0

Integer

Bounding rectangle coordinates, in pixels (x, lower left)

 

15

BR_PIX_Y0

Integer

Bounding rectangle coordinates, in pixels (y, lower left)

 

16

BR_PIX_X1

Integer

Bounding rectangle coordinates, in pixels (x,upper right)

 

17

BR_PIX_Y1

Integer

Bounding rectangle coordinates, in pixels (y,upper right)

 

18

FEAT_MAX_INT

Integer

Feature maximum value, in units of the original obs.

As in UNITS

19

FEAT_MIN_INT

Integer

Feature minimum value, in units of the original obs.

As in UNITS

20

FEAT_MEAN_INT

Float

Feature mean intensity value, in units of the original obs.

As in UNITS

21

ENC_MET

String

Encoding method

e.g. raster, chain code, None… TBC

22

CC_PIX_X

Integer

Coding 1st position in pixels, X axis

 

23

CC_PIX_Y

Integer

Coding 1st position in pixels, Y axis

 

24

CC_ARC_X

Float

Coding 1st position in arcsecs, X axis

 

25

CC_ARC_Y

Float

Coding 1st position in arcsecs, Y axis

 

26

SKE_LNTH_DEG

Float

Skeleton length in degrees

 

27

CURVATURE

Float

Curvature index (from 0 to 10)

ratio btw length and distance btw end points

28

ELONG

Float

Elongation factor (-1 if not enough points)

Area/(2d)² where d=thickness

29

ORIENTATION

Float

Global orientation of the filament (CCW from Ox axis)

 

30

CC_SKE_PIX_X

Integer

Skeleton coding 1st position in pixels, X axis

 

31

CC_SKE_PIX_Y

Integer

Skeleton coding 1st position in pixels, Y axis

 

32

CC_SKE_ARC_X

Float

Skeleton coding 1st position in arcsecs, X axis

 

33

CC_SKE_ARC_Y

Float

Skeleton coding 1st position in arcsecs, Y axis

 

34

CHAIN_CODE

String

Chain code of the filament boundary

 

35

CC_LNTH

Integer

Number of pixels included in the chain code

 

36

CHAIN_CODE_SKE

String

Skeleton chain code

 

37

CC_SKE_LNTH

Integer

Number of pixels included in the skeleton chain code

 

38

PP_LOCAL_FILENAME

String

Name of the pre-processed file, including the full path from the local organization

Internal use

 

                                                Go to top or Go to SFC

                                   Download the SFC hitchhiker's guide as a .doc file