NAME

hstpos --Plot the position of HST on a map of the world.

USAGE

hstpos input orbit

DESCRIPTION

hstpos plots the position of the spacecraft at a specific time on a Mollweide projection of the world. The task uses the orbital parameters contained in the standard header packet image (the .shh file). The time for which the position is calculated is taken either from a header keyword in an image or a list in a user-created ASCII file.

If an input image is not specified, then both the orbital information and time information will be taken from the .shh file.

A variety of markers and a user-sepcified marker size are available for identifying postions. Plots containing multiple markers can be produced by appending plots to previously drawn plots.

Line of constant geomagnetic latitude can be plotted using the parameters geomag, n_latitudes, and latint. n_latitudes specifies how many lines of constant latitudes from the equator northward are drawn. The number of lines drawn in the north will be mirrored in the south. latint determines the number of degrees between each line of constant latitude.

Contours of the South Atlantic Anomaly (SAA) can be plotted by specifying a model number in the parameter model. The number refers to the model number specified in th Project Database (PDB) file SVDF.DAT. hstpos uses a table version of this file which is specified in the parameter saa. (Refer to the document ICD-26 Part III for more information on SAA contour models).

PARAMETERS

input [file name]

The input images for which positions are to be plotted.

Wildcard specifications and lists are supported. If no group specification is given for a multigroup file, all groups will be processed. The times at which to determine positions are extracted from the headers of these images. The header keyword containing the time of interest is specified by the parameter timekey.

Instead of image names, this input list may contain specific times at which to determine position. These times may have one of two formats: Modified Julian Date (MJD) or DD-MMM-YYYY HH:MM:SS.SS.

orbit [file name]

The image name of the standard header packet (the .shh file) containing the orbital parameters to be used.

(timekey = "pkttime") [string, allowd values: pkttime | fpkttime |

lpkttime]

The header keyword that contains the packet time. The positions plotted correspond to the position of the spacecraft at the time given in this header keyword. This keyword should have the time in Modified Julian Date (MJD) but may have (for old-format data) the time expressed as a string with the format: DD-MMM-YYYY HH:MM:SS.SS.

(position) [file name]

Name of the table in which the calculated longitude and latitude are to be written. If the table already exists, the new information is appended, otherwise the file is created.

(plot = yes) [boolean]

Plot positions on the device specified by the device parameter?

(allgroups = yes) [boolean]

Loop through all groups in a GEIS multigroup image?

If allgroups = no, only the first or specified group will be processed.

(model = INDEF) [integer]

If specified, this contains the South Atlantic Anomaly model to plot.

(saa = "playpen$saa.tab") [file]

The table containing the Sough Atlantic Anomaly model contours.

(device = "stdgraph") [string]

The output device (e.g., stdgraph, stdplot, lp1).

(marker = cross) [string, allowed values: point | box | plus |

cross | circle | diamond | hline | vline | hebar | vebar]

The marker style for each plotted point. Most are self explanatory, however, "hline" is a horizontal line, "vline" is a vertical line, "hebar" is a horizontal error bar and "vebar" is a horizontal error bar.

(szmarker = 0.01) [real]

The size of the markers in normalized device coordinates (NDC). Anything much larger than the default blots out major land features.

(append = no) [boolean]

Append to an existing plot? If append = yes, the map is not drawn. The data are drawn at the scale set by the previous plot.

Warning: Don't try to append to plots that have been sent directly to a printer.

(geomag = no) [boolean]

Draw lines of constant geomagnetic latitude?

(n_latitudes=3) [integer]

The number of lines of constant latitude from the equator northward that will be drawn. What is drawn in the north is then mirrored in the south.

(latint = 10.) [real]

The number of degrees between each line of constant geomagnetic latitude.

EXAMPLES

1. Plot the position of the spacecraft at the time that each group of the standard header packet image was dumped. This corresponds to the begin time of an HRS observation.

  hr> hstpos z00xh903r.shh ""

2. Repeat the first example, but only plot group number 5.

  hr> hstpos z00xh903r.shh[5] ""

3. Use the orbital parameters in z00xh903r.shh but plot the positions at the time each group of the unique data log (.ulh file) was dumped.

  hr> hstpos z00xh903r.shh z00xh903r.ulh

4. Use the orbital parameters in y00vk108r.shh but plot the position at the time the first group of the science data (.d0h file) was dumped.

  hr> hstpos y00vk108r.shh y00vk108r.d0h[1] timekey=fpkttime

5. Use the orbital parameters in z00xh903r.shh but plot the positions at each of the times listed in the ASCII file, time.in.

  hr> type time.in
  # Sample list of times
  01-JAN-1991 10:23:58.33
  01-JAN-1991 10:43:00.99
  48257.07
  48257.08
  01-JAN-1991 12:23:58.33
  01-JAN-1991 01:43:11.25
  hr> hstpos z00xh903r.shh time.in

6. Plot diffenent positions with different markers on the same plot.

  hr> hstpos z00xh903r.shh z00xh903r.ulh[1] marker=diamond
  hr> hstpos z00xh903r.shh z00xh903r.ulh[2] marker=box append+
  hr> hstpos z00xh903r.shh z00xh903r.ulh[3] marker=cross append+
  

BUGS

SEE ALSO