Viewing contents of file '../idllib/ssw/allpro/aide.pro'
pro aide, SUJET = sujet, message
; Aide en ligne des logiciels NRH1
message = ["No subject selected for HELP !!! ",$
" Format: aide, SUJET = subject, message" ]
IF NOT KEYWORD_SET(SUJET) THEN RETURN
; -----------------------------------------------------------------------------
IF sujet EQ "filenames" THEN BEGIN
message = [ $
" ", $
"NRH1 handles 1D images from the NRH and parameters derived from", $
"these. When the appropriate computations are carried out, NRH1 ", $
"generates new files with standard file names, based on the name of", $
"the 1D image file.", $
" ", $
"The 1D image files are named ", $
" name.ext,", $
"where ext is 'ewN' or 'nsN', depending on the NRH array. N is a ", $
"number that designates the observing frequency, in general ", $
"N=1, 2, ... in the order of increasing frequency. ", $
" ", $
"Image files from which a reference scan has been subtracted ", $
"(option DIFFERENCE) have the standard name ", $
" bck_name.ext.", $
" ", $
" 1D position files contain the channel of the centroid, the width, ", $
"amplitude and flux density of localized sources in the 1D images. ", $
"Their standard names are", $
" 'pI' + name.ext (Stokes parameter I) ", $
" 'pV' + name.ext ( Stokes parameter V). ", $
" ", $
" 2D position files are constructed from 1D position files. They ", $
"contain the heliographic co-ordinates in solar radii and the ", $
"flux densities measured with the EW and NS arrays of the NRH. ", $
"They have the same name as the 1D postion files. Their extension ", $
"is '2dN' (N as above). ", $
" ", $
"Flux files contain the flux density, both I and V, the centre", $
"and the width of the channel interval over which the flux density", $
"is evaluated. Their name is ", $
" 'f' + name.ext .", $
" ", $
"Note that when you compute a new position from the same file of ", $
" 1D images, the result will be written in the existing position", $
"file. The same is true for the 2D position files and the flux files.", $
" ", $
"The standard file names may be changed by the user. " $
]
ENDIF
; -----------------------------------------------------------------------------
IF sujet EQ "traces" THEN BEGIN
message = [ $
" ", $
"The following options are available:", $
" ", $
"CONTOURS: Contours or colour levels of constant 1D-brightness ", $
" (Stokes param. I or V) as a function of time. ", $
" Further options: Identification of local sources, ", $
" computation of their parameters. ", $
" Plot of centroid position upon contours.", $
" ", $
"SCAN: Spatial scan of 1D-brightness (Stokes param. I and/or V)", $
" Options: plot of a single scan (opt. 'SCAN'), ", $
" single scan + identification of local ", $
" sources (opt. 'SCAN+DECOMP'), ", $
" series of scans (opt. 'SERIES')", $
" 'movie' of scans (opt. 'ANIMATION')", $
" ", $
"F(TIME): Time history of a parameter. The parameter is contained",$
" in a 1D 'position' file, a 1D 'flux' file, or a 2D 'position'",$
" file (examples: channel, amplitude, flux, heliogr. EW-coord.)", $
" ", $
"MAP: Map of heliographic positions, read from a file or entered by", $
" the user. " $
]
ENDIF
IF sujet EQ "calculs" THEN BEGIN
message = [ $
" ", $
" 2D POS: Heliographic positions. Input: 1D positions (EW & NS).", $
" ", $
" 1D FLUX: Flux density of 1D images (I & V). Input: 1D images.", $
" ", $
" DIFFERENCE: Computation and subtraction of an average scan from ", $
" 1D images. ", $
" SHIFT FOV: Fold part of a 1D image from the western to the eastern",$
" or from the northern to the southern border, in order to", $
" enable tracking of a source which quits the field of view."$
]
ENDIF
; -----------------------------------------------------------------------------
IF sujet EQ "listings" THEN BEGIN
message = [ $
" ", $
"CHECK HEADER: Listing of the header of an NRH1 file.", $
" ", $
"F(TIME): Listing of a file describing the time history of a ", $
" series of parameters (1D 'position' file, 1D 'flux' ", $
" file, 2D 'position file). Output on screen or in an ", $
" IDL SAVE/RESTORE file. " $
]
ENDIF
; -----------------------------------------------------------------------------
IF sujet EQ "plot_options" THEN BEGIN
message = [ $
" *** Information on plot options: *** ", $
" ", $
"Plot to X/ to PS: Select output. 'PS' creates a postscript file", $
" result.ps. This file is overwritten each time", $
" you select 'Plot to PS'. You can save it by ", $
" changing the name ('UNIX or VMS command'). ", $
" Switch back to 'Plot to X'in order to close ", $
" the postscript file.", $
" ", $
"BLACK & WHITE/COLOUR: Required for PS colour output only. ", $
" ", $
"PORTAIT/LANDSCAPE : Format of the POSTSCRIPT output. ", $
" ", $
"PRINT PS FILE ... : Print file result.ps on the selected printer. ", $
" ", $
"VIEW PS FILE ... : Display result.ps on screen (GHOSTVIEW). Note", $
" that colour output may be plotted black & white", $
" on screen if GHOSTVIEW is called while IDL is ", $
" operating. In this case you must quit your IDL", $
" session if you want to make sure that the PS ", $
" file is coloured.", $
" ", $
"Nb. of plots (x, y): Number of plots in the horizontal (x) and ", $
" vertical (y) direction.", $
" ", $
"Window width/height: Width and height of the X-window in pixels.", $
" For PS output, the plot fits within an A4 page.", $
" ", $
"PROBLEMS KNOWN TO DATE: The juxtaposition of several plots on one ", $
" page is not sure to give satisfying results."$
]
ENDIF
; -----------------------------------------------------------------------------
IF sujet EQ "choix_isoph" THEN BEGIN
message = [ $
" *** Choice of contour levels: ***", $
" ", $
"Highest contour = x*Imax (Imax=peak level in the plotted field, ", $
"x = value of the '% of peak level'-slider). ", $
" ", $
"The step dI between contours may be chosen in one of the following", $
"ways:", $
" ", $
" 1) linear scale, contours 0.5*dI, 1.5*dI, ... , x*Imax ; ", $
" (x*Imax = (N-0.5)*dI, N='number of contours'); ", $
" ", $
" 2) linear scale, x*Imin, x*Imin+dI, ... , x*Imax (Imin=smallest ", $
" peak value in the 1D images contained in the plotted field); ", $
" this option is suited for fields with a large dynamic range; ", $
" ", $
" 3) logarithmic scale between the same minimum and maximum values", $
" as 2).", $
" ", $
"For V contours the highest contour is x * peak of the ", $
"absolute values of the amplitudes; the lowest contour is ", $
"the negative value of the highest one. Therefore the number of ", $
"contours actually plotted may be smaller than the chosen value N. " $
]
ENDIF
; -----------------------------------------------------------------------------
IF sujet EQ "recherche" THEN BEGIN
message = [ $
" *** Extraction of elementary sources from 1D images: ***", $
" ", $
"An elementary source is identified by comparing the raw image with", $
"the running mean over N channels (N='Mean [chan]'). A Gaussian or", $
"its sum with a constant, straight line, or parabola, is fit to the", $
"data within the two local minima around the brightest point of the", $
"image. The Gaussian part of the fitted function is subtracted from", $
"the image. This procedure is repeated as long as the number of ", $
"iterations does not exceed the pre-selected value ('Iterations'), ", $
"and while the excess of the brightest point is greater than W times",$
"the maximum excess in the field (W='Weight'). You can see how this", $
"works in an individual 1D image by using the 'DECOMP' option of ", $
"the SCAN menu. ", $
" ", $
"Upon pushing 'Extract individual sources', you are requested to ", $
"delimit a field in the contour/gray-scale plot encompassing the source ",$
"you want to analyze. The central scan of the delimited field is taken. ", $
"The brightest source is identified, and is searched for in preceding ", $
"and following images. The procedure continues as long as it",$
"identifies a source whose distance to the one previously found is ", $
"smaller than the pre-selected value ('Dist [chan]'). The data are ", $
"written into a 'position' file, which may already exist or not. If", $
"it exists, the procedure checks whether the source to be written ", $
"is already there or not. " $
]
ENDIF
; -----------------------------------------------------------------------------
IF sujet EQ "par_image" THEN BEGIN ; Parametres d'une image (CARTE 2D)
message = [ $
"Underlay an image under the plot of heliographic positions. ", $
"The co-alignment of the image with the positions is achieved ", $
"by giving the centre and the radius of the solar disk in ", $
"pixels, and the inclination (in degrees) of the vertical axis ", $
"with respect to the solar north-south direction (the angle is ", $
"positive when solar north is on the right of the vertical through", $
"the centre of the disk).", $
" ", $
"You may enter these values manually. In case data are read from a ", $
"fits file, use 'FITS HDR' to print the fits header. ", $
" ", $
"You can also compute them from an image: choose option ", $
"'COMP. C, r'. The image will then be plotted on the screen, and ", $
" the IDL-procedure CIR_3PNT will be called which determines the ", $
"centre and radius of a circle when three points are given on the ", $
"circumference (click on these points upon request in the MESSAGE", $
"window of the widget). If necessary, determine the inclination ", $
"in a similar way by clicking on 'COMP. incl.'." $
]
ENDIF
IF sujet EQ "pos_man" THEN BEGIN ; Positions 2D; entree manuelle
message = [ $
"Heliographic positions can be computed from the 1D centroid positions", $
"(observed with the EW and SN branches of the NRH) expressed in ", $
"channels. These positions are plotted by a symbol chosen as a ", $
"function of frequency or by the user (button Plot layout). If the ", $
"widths of the 1D sources are >0 (units: channel), a cross is plotted. ", $
" ", $
"The calculation of heliographic positions does not correct for", $
"refraction in the Earth's ionosphere (button No corr.), or", $
"attempts a correction using a static model (button static corr.).", $
"Correction using electron density measurements from the Poitiers ", $
"station does not work for the time being. ", $
" ", $
"You can save the source parameters set in the fields to a file by", $
"pushing the button WRITE. READ displays the data in this file as ", $
"a list widget from which you can choose a data set (push Done when", $
"ready). SET puts this data into the fields for manual entry. The", $
"file (named manpos_nrh.dat) contains ASCII data and can hence be ", $
"edited. " $
]
ENDIF
IF sujet EQ "pos2d" THEN BEGIN ; Calcul positions 2D
message = [ $
"Computation of heliographic positions from one-dimensional ",$
"positions from the east-west and north-south branches of the NRH.",$
" ",$
"Choose the name of the file containing 1D EW - positions and",$
"make sure that the corresponding file with north-south positions",$
"exists. Push INIT before starting the computation, WRITE FILE",$
"when all 2D positions have been computed (maximum number of 2D ",$
"positions allowed: 9). ",$
" ",$
"The start and end time of the interval during which the helio- ",$
"graphic positions are computed can be selected. The east-west and",$
"north-south positions are associated as indicated by the numbers",$
"('EW pos. # m', 'NS pos. # n'). ",$
" ",$
"Corrections for propagation in the terrestrial ionosphere can be",$
"applied with a static model or using ionospheric density measure-",$
"ments taken in Poitiers. THESE OPTIONS DO NOT YET WORK." ,$
" ",$
"After each computation the computed heliographic position is plotted." ,$
"This plot is for control purposes only. It cannot be directed to" ,$
"a PS-file." $
]
ENDIF
IF sujet EQ "calcflux" THEN BEGIN ; Calcul flux 1D
message = [ $
"The flux density is the integral of the 1D brightness distribution.",$
"It is computed within an interval of NRH channels that can be ", $
"selected by the user (widget min:/max:). The default interval is ", $
"the whole image.", $
" ", $
"The flux density can be evaluated over a fixed interval (option ", $
"'Fixed interval') or by tracking the point of maximum brightness ", $
"(option 'Track peak'; in this case 'Width [chan]' gives the width ", $
"of the range, centered at the peak, over which the flux density is ",$
"computed.", $
" ", $
"The output is written to a file.." $
]
ENDIF
RETURN
END