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HMI Ring Diagrams
Pipeline Module Specifications
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maicalc
Module Version
2.4 16 II 2021
General Description
maicalc takes as its input a dataset of records representing solar
magnetograms during a selected interval, and produces as its output
the values of the Magnetic Activity Index (MAI) appropriate for a
selected set of target locations as they would be mapped and tracked
by mtrack for the duration of the input data interval and apodized by
pspec3. The MAI values may be used as a set of input parameter values
to mtrack, and will be used to set appropriate keyword values in its
output data records. Also writes an output file containing values at
grid points of integrated values of Bz as well as |Bz| and the
time derivatives of both.
Status
This version has been superseded by Version 2.5
Included in JSOC release 9.41
In use for the ring-diagram pipelines from 2021.02.19 – 2021.11.05
This version supersedes Version 2.3
The source code and Makefile are in the JSOC CVS repository
Usage
maicalc [flags] los= DataDescriptor length= tracking length
scale= target tile mapping scale extent= target tile size
lat= target latitude(s) lon= target longitude(s)
[param= val ...]
Flags
-f force filling or reporting of records for which there are
no valid data
-l list MAI values only on stdout
-n turn off tracking, just correct for any observer drift
in the latitudinal direction
-r turn off spatial apodization
-s turn off despiking (elimination of outliers)
-v run verbose (overrides -l flag)
-M apply (new) MDI distortion model
-O apply old MDI distortion model
-S suppress correction of SDO Carrington longitude and position angle
Parameters
los Either the name of an input LOS magnetogram data set (record
selection) or the name of an input LOS magnetogram data series;
in the latter case, tmid and length parameters must also be
supplied. No Default, must be provided
length The length of the analysis interval, in units of the input cadence.
No Default, must be provided
scale The scale of the mapped region(s) at map center, in
heliographic degrees per pixel. No Default, must be provided
extent Extent of the integrating analysis region(s), in
heliographic degrees. No Default, must be provided
lat An array of heliographic latitudes (in degrees) of the
centers of regions at the midpoint of the tracking.
If there is more than target, the comma-separated list must
enclised in brackets, braces, or parentheses.
If there are more lon values than lat values, the final
lat value is replicated.
No Default, must be provided
lon An array of heliographic longitudes (in degrees) of the
centers of regions at the midpoint of the tracking.
Default: [0.0] If there are more lat values than lon
values, the final lon value is replicated. Note that
the target longitudes are Carrington, not Stonyhurst.
No Default, must be provided
los_seg Name of the segment in the LOS magnetogram series containing
LOS magnetograms. Default: unspecified, implies first of Rank 2.
vec Name of an input vector magnetogram data set or data
series. Default: unspecified N. B. This option is not supported;
the value will be ignored.
mai Name of an output data series for which records will be
populated with appropriate keys.
Default: unspecified, implying no record creation
tmid Midpoint of the target analysis interval, expressed either
in standard DATE_TIME format or in CR:CL format.
Default: unspecified; if not specified, then the values
for cr and cl are used.
cr The Carrington rotation number at the target midpoint
of the analysis interval. Default: current value.
cl The Carrington longitude of central meridian at the target
midpoint of the tracking interval. Default: current value.
qmask A bit mask for image rejection aplied to the Quality
keyword specified by qual_key; Default: 0x80000000
reject Name of a file containing a list of input magnetograms
to be rejected regardless of Quality.
Default: unspecified, implies none
rec_step The sampling step, in units of the input record steps.
Default: 64
max_reach Maximum distance allowed from a rejected or missing record
in the magnetogram dataset to an acceptable replacement record,
in units of the rec_step value. Default: 0.5
mask_in The inner edge for a (1-r^2) apodization to be applied
to the mapped regions; Default: 0.9765625
mask_ex The outer edge for a (1-r^2) apodization to be applied
to the mapped regions; Default: 1.0
apodize Inner edge of a (1-t^2) temporal taper; Default: 0.96875
floor The "noise" floor below which data values are ignored for
the sake of integration (gauss); Default: 50.0
tobs_key The key name to be used for the key value representing the
effective observing time
Default: T_OBS
trec_key The key name to be used for the key value representing the
(slotted) prime key for reference time
Default: T_REC
tstp_key The key name to be used for the key value representing the
cadence associated with the reference times
Default: CADENCE
qual_key The key name to be used for the key value representing the
data quality word (a 32-bit mask used in conjunction with
the qmask value for image rejection;
Default: Quality
clon_key The key name to be used for the key value representing the
observer Carrington longitude in degrees at the time of
observation in the input data series;
Default: CRLN_OBS
clat_key The key name to be used for the key value representing the
observer heliographic latitude in degrees at the time of
observation in the input data series;
Default: CRLT_OBS
crot_key The key name to be used for the key value representing the
Carrington rotation number appropriate to the observer
central meridian at the time of observation in the input
data series; Default: CAR_ROT
rsun_key The key name to be used for the image semi-diameter in
pixels in the input data series; Default: R_SUN
apsd_key The key name to be used for the solar semi-diameter in
arcsec in the input data series; Default: RSUN_OBS
dsun_key The key name to be used for the sun-observer distance in
meters (to be used in conjunction with rsun_key in default
of a keyword for apsd_key; Default: DSUN_OBS
Input Data series class:
time series of solar magnetogram data
Sample input series:
hmi.M_45s
mdi.fd_M_96m_lev182
Comments:
If tracking is turned off, the location of the target region will be
appropriate for the midpoint of the tracking interval. For example, if
the target interval ranges from central meridian longitudes 190–170
and a target region is at Carrington longitude 150, the Stonyhurst
longitude of the target would remain at 30° east for the duration of
the analysis interval.
Sample command:
maicalc los= hmi.M_45s mai= hmi.rdMAI_fd30 cr= 2100 cl= 180.0 \
scale= 0.04 extent= 30.72 length= 4608 rec_step= 64 \
qmask= 0x8001c540 max_reach= 0.5 \
reject= /home/jsoc/hmi/tables/LHS_reject.m45 \
floor= 50 mask_in= 0.9765625 apodize= 0.96875 \
lat= "{-60.0, -60.0, -45.0, -45.0, -30.0, -30.0, -15.0, -15.0, \
+00.0, +15.0, +15.0, +30.0, +30.0, +45.0, +45.0, +60.0, +60.0}" \
lon= "{120.0, 240.0, 135.0, 225.0, 150.0, 210.0, 165.0, 195.0, \
180.0, 195.0, 165.0, 210.0, 150.0, 225.0, 135.0, 240.0, 120.0}"
Significant changes from Previous Version
— Fixed possible bug introduced in previous version for the correction
of SDO CMLon in certain cases, but probably never reached, as verified
by multiple test cases.
Bugs in current version
Processing of vector magnetic field data is not implemented
Selection of input data records as a DRMS DataSet name is not supported;
the los or vec parameter value should be a DataSeries name, and values
for either the tmid or the cr, cl, parameters and the length parameter
must be supplied. If a data record selector is included in the los or vec
string, it is ignored.
The los_seg parameter is not supported — it must be left unspecified.
Time selection by Carrington Longitude is based on the Earth ephemeris
The default value for the mask_in parameter is not the same as that for
module pspec3, but rather the value used in the HMI rings pipeline
There is no option for tracking at rates other than the Carrington rate
(or not at all).
Calculation of maximum distance from center of image may not be correct
in case of no tracking.
There is no option for mapping using a projection other than the Lambert
azimuthal equivalent projection.
When the tmid parameter is specified in CR:CL format (as it is in the
ring-diagrams pipeline) or left unspecified in favor of the cr and cl
parameters, the time center of magnetograms selected for analysis is
that of the last record before the target time. This results in an
average bias of the mean observation time of one-half of the magnetogram
cadence before the target time. (This is consistent with the time bias
for the corresponding tracked cubes.) For HMI, where the magnetogram
cadence is 45 sec, the bias is inconsequential, but for MDI, where the
magnetogram cadence is 96 min, the bias is quite substantial.