Provided by: seesat5_0.90.10-1.1_amd64 bug


       seesat5 - provides satellite visibility information.


       This  man page explains the commands used by seesat5 to produce and control the satellites
       that will be analysed and the output criterion.  These  commands  are  valid  for  use  in
       SEESAT5.INI, in the command line, and from the seesat5 prompt.


       MAXELEV <number>
              This  selects  data  where the calculated elevation is less or equal to the entered

                  MAXELEV 70

              means that only elevation values of 70 or less will be  selected.  Only  satellites
              that are at 70 or less degrees in elevation will be selected.

       MINELEV <number>
              This selects data where the calculated elevation is greater or equal to the entered

                  MINELEV 15

              means that only elevation values of 15 or more will be  selected.  Only  satellites
              that get to 15 or more degrees in elevation will be selected.

       MINPHASE <number>
              This  selects  data where the calculated phase angle (the angle between the sun and
              the satellite as seen by the observer), is greater or equal the entered value.

       MINRANGE and MAXRANGE <number>
              This selects data where the range of the satellite is  within  these  limits.   The
              number  denotes either miles or kilometers depending upon whether you set the MILES
              or KILOMETERS option. If the satellite never gets between the MINRANGE and MAXRANGE
              values  at  your  location,  then no data is printed for it. The default values for
              MINRANGE and MAXRANGE is zero and 65535 respectively.

       SET and RESET
              These commands are used to set and reset  conditions  and  options.   They  are  as
              follows :

                  SET SHOWTLE
                  SET SHOWNORAD

              is  is useful when you want to see all the data using the ALL command. If you don't
              reset the selection conditions, the program does not print any  lines  because  the
              conditions   are  not  satisfied.  The  values  for  SHOWTLE,  VISMAG,  SUNELEVSAT,

              This varient of SET determines whether distances are to  be  printed  in  MILES  or
              KILOMETERS. Various people can only visualize distance in one or the other of these

              When this option is SET, the age (in days) of the element is displayed. This is the
              age  of  the element at the time for which the satellite data is printed. Also note
              that this value is UTC relative.  For example, if you do a whole weeks run with the
              same  satellite  elements  and  the satellite is visible every day, then the TleAge
              value will be 1 day greater in each days printout.

              Show the satellite NORAD number on the printout.

              Controles the printing of the Keplerian elements when a LOAD or NEXT is done.  When
              SET, Keplerian elements are printed. When RESET, they are not

       SUNELEVOBS <number>
              This selects data where the calculated SUN's elevation at the observers location is
              less or equal the entered value.

                  SUNELEV 0

              means select data when the sun is at or below the horizon. This will let you filter
              out satellite's that pass over in daylight.

       SUNELEVSAT <number>
              This  selects data where the calculated SUN's elevation at the satellite is greater
              or equal than the entered value.

                  SUNVAL 0

              means that only positive SUN values will be selected. This  lets  you  select  data
              when the sun is shining on the satellite.

       VISMAG <number>
              This selects data where the MAGNITUDE is less or equal to the supplied value.

                  VISMAG 1.0

              means  the  calculated  magnitude  must be less than or equal to 1.0. This lets you
              select bright satellites only.

       ALL    Toggles between normal mode (predictions below horizon suppressed) and a mode which
              displays all predictions.

              This  command  requires  a  file  name  parameter.  This is the same as the OPENSDF
              command except the file is opened for extend. If the file named does not exist,  it
              will be created.

       BLOCK  This command is used to customize the skyline that you view from. It has the format
              BLOCK begin-azimuth end-azimuth elevation. The azimuth values are integers  between
              0  and  359  and  the  elevation  0 and 90 degrees.  You can use this to accurately
              define your view of the sky. You can enter  up  to  30  block  commands,  each  one
              defines  a  block  from  a  starting azimuth, ending azimuth and an elevation. If a
              satellite never gets out from behind the blocks you define then its data  will  not
              be  printed.  If  at  any  time (be careful with time steps here), the satellite is
              visible, then its data is printed and the data where it is behind a block  will  be
              printed  with  a particular time you will not be able to see the satellite although
              it is above the horizon.  The MINELEV command is a more simplified version of BLOCK
              and  only  useful in an open field where the "mist line" at the horizon is uniform.
              BLOCK provides a better solution for "city dwellers" where buildings tend to  block
              only some areas of the sky.

       CENTER Followed by a time, this command determins the time to center the data run, usually
              used in conjuction with SPAN.

              If you want to put comments inside your SEESAT5.INI file, just type  in  a  forward
              slash  (/)  anywhere  you want. When the slash is at the start of a line the entire
              line is treated as a comment. When it is in the middle of a line,  everthing  after
              the slash up to the end of the line is treated as a comment.

              This  command  is  reserved  for  use  in SEESAT5.INI. When seesat5 encounters this
              command it executes the commands found on the command  line  as  though  they  were
              located in the init file where the cmdline command is located. The main use of this
              command is to impliment the "go label" command. Typically the init file begins with
              setup  commands  that  set  the  viewing  location  as  well as some general filter
              criterion. Following this with cmdline, followed by as many blocks of  instructions
              as  you  like,  each  one beginning with a unique label, allows a runtime choice of
              which block to execute.

       DBS and DBS#
              To select satellites you want to run predictions on.  You  can  maintain  the  list
              inside  the  seesat.bat  file,  together  with comments. You may load the satellite
              either by name or by Norad Satellite Number.

                  DBS "HST ARRAY"              / Last seen 2/3/94, dim, blinks
                  DBS HST                      / Last seen with shuttle
                  DBS "OKEAN 1"                / Fast
                  DBS MIR                      / Must see soon
                  DBS 23028                    / SEDS 2
                  DBS# 16609                    / Its MIR again

              After selecting your favorite satellites,  run  the  prediction  using  the  RUNDBS

              RUNDBS is like RUNTIME but just runs satellites in your database.  You can still do
              RUNALL or RUNTIME any time to run all the satellites loaded with your last OPEN.

              If you want to select another set of DBS satellites, you can either OPEN a new  TLE
              file  (that  resets all the DBS entries to false), or more efficiently (if you want
              to keep the current TLE file open), use the RESET DBS command.

       EX <filename>
              Execute a batch file of commands.  Any SEESAT command may appear in a  batch  file.
              Multiple  commands  per  line are allowed, just as if you were entering the command
              line manually.  EX itself may be in a batch file.  If encountered,  it  will  close
              the  current  batch  file and begin executing the specified file.  Control will not
              return to the preceding file.  I.e., you can chain batch files but not nest them.

       EXIT   Exit from seesat5.

       GO or GOTO
              Requires a label name to go to, and starts processing there. The  GOTO  command  is
              probably  going  to  be  most  useful  from the command line to let you jump into a
              particular SEESAT5.INI  file  section  of  your  choice.  Obviously,  any  commands
              following  the  GOTO  will  not be processed.  When you specify a GOTO command, the
              program begins searching the SEESAT5.INI file from the beginning and looks for  the
              LABEL  <labelname>  line.  If  one  is  not found, the message END OF BATCH FILE is
              displayed and the program goes into keyboard command mode. If  you  have  duplicate
              labels,  the  first  one will be processed. No checking is done to prevent you from
              making the program loop continously, so be careful. Also, if you use  EX'ed  files,
              the GOTO will only goto labels in the current file that is open.

       HELP   Displays a help screen.

       HEIGHT <number>
              Number,  specifies,  in  kilometers,  the  height  of  the viewing location. Errors
              incurred from  incorrect  values  for  height  have  little  propogation  into  the
              satellite  location  prediction. As a result, if you don't know your height, it may
              safely be left 0.

       INDEX  Lists the satellites in the currently  open  file.   If  there  is  more  than  one
              screenful,  it  will  pause  with  a "more>" prompt.  At this prompt you may either
              press RETURN to continue the listing, or enter a command (or commands) just as  you
              would  at the normal command prompt.  In that case, the listing is aborted and your
              commands are executed.

       LABEL  This command requires a parameter that is a label that you want to GOTO later.  The
              maximum label length is 30 characters and it must be the FIRST command on the line.
              More commands are allowed after the label name if you want, but  I  found  it  more
              readable to have the command on a single line.

                  LABEL DAILY-RUN

              Use  labels  to  keep  my  run  parameters  for  different  situations  in a single
              SEESAT5.INI file and select which ones to process using the GOTO command.

       LAT <number>
              The number, in degrees, specifies the latitude of the viewing  location.   Southern
              latitudes  are  declaired  with  a  negative  number. Precision in this location is
              critical. A .14 degree error in location, approximately 10 miles  will  cause  a  1
              degree error in the satellite position.

       LENGTH <integer>
              Sets maximum number of characters the OPEN command will consider significant in the
              satellite name when building the index.   The  LENGTH  command  must  therefore  be
              issued  before  OPEN,  to  have  any  effect.   Any  number from 1 - 22 is allowed.
              Default is 22, and may be left alone unless you're using a file such  as  Molczan's
              N2L  series.   In  that  case, you'll want to reduce LENGTH to 15 to prevent SEESAT
              from using the extra data as part of the satellite name.  LENGTH is set  to  22  if
              you enter a number larger than 22.

              This  command  as added for predictions done on a machine where a typical run takes
              hours. Starting the run with the  output  redirected  to  the  printer  serves  two

              1.   to print out the data, and
              2.   to serve as an alarm.

              How  does this serve as an alarm? With a dot matrix printer the machine can be left
              to run. While other work gets done  the  machine  chuggs  along.   Eventually,  the
              program  finds  a satellite that can be seen. When the printer starts clacking away
              after the long silence you know that there is new data available. So that  you  can
              come  to  the  printer and tear off the new data without interfering with potential
              new printing this command prints a selected number of linefeeds after the satellite

       LOAD <name>
              Loads  the  named satellite from the file you opened with the OPEN command.  If the
              name has spaces, begin the name with quotes.

       LOAD# <number>
              This is just like the original LOAD  command  except  you  must  supply  the  Norad
              Satellite  number.  This  is  most  usefull  when you have TLE files from different
              sources and the satellite names are not consistent.

       LON <number>
              The number, in degrees, specifies the longitude of the viewing  location.   Western
              longitudes  are  specified  with  a  negative number. As with latitude a relatively
              small error of .14 degrees will cause a 1 degree error in the satellite location.

       MAG <number>
              For entering the absolute magnitude of a satellite.  It will be adjusted for  range
              and  illumination  angle  to  generate  the  "mag"  value  in the prediction table.
              Absolute magnitude is its magnitude at 1000 km and 50% illuminated (i.e., 90 degree
              phase  angle).   Absolute  magnitude  input  can be automatic during loading of the
              elements from the file.  If the first line of the element set (the  satellite  name
              line)  is longer than 32 characters, SEESAT assumes it's a Molczan format line, and
              reads the magnitude.  You can  use  the  MAG  command  to  override  the  value  if

       MAGBIAS <number>
              Bias  to be applied to SEESAT's computed magnitude before display.  A negative sign
              is allowed.  The default is zero.  If your absolute magnitudes assume  a  different
              range and/or illumination than 1000 km and 50%, the MAGBIAS command will bring your
              scale into coincidence with SEESAT's.   If  r  and  k  are  your  assumed  standard
              conditions (in km and percent, respectively), set MAGBIAS to:

                  2.5 * log10 ((1000/r)^2 * k/50)

              For  example, if your absolute magnitude is for 1000 km range and 100% illuminated,

                  MAGBIAS .8

              The satellite longitudes in the prediction table may be computed  with  respect  to
              either  Greenwich  or your local meridian.  MERIDIAN toggles this mode, and informs
              you of the current mode.  Default is Greenwich.

       MOON <date time>
              Print the azimuth & elevation of  the  moon  at  the  given  time.   Percentage  of
              illumination is also given.

       NEXT   Loads the next satellite from the current open element file.

       NOMINAL <date time> / ACTUAL <date time>
              These  commands  adjust the epoch and RAAN of the currently loaded elements for the
              difference between the nominal and  actual  launch  times.   They  are  useful  for
              correcting a prelaunch element set.

                  NOMINAL 19 1851 ACTUAL 1918

              tells  SEESAT  that  the  currently  loaded elements assume a launch on the 19th at
              1851, but the launch actually occurred at 1918.  You can't use NOMINAL or ACTUAL by
              itself!   If  you use one, you must also use the other or you'll get crazy results.
              The order of the commands does not matter, and they don't have to be  on  the  same
              line.  Just be sure that both commands have been given before starting a prediction
              run.  The entered values are remembered.  So you may, for example, use NOMINAL just
              once,  then  experiment with different ACTUAL values.  Loading an element set (even
              reloading the same one) disables the effect of NOMINAL and  ACTUAL.   Their  values
              are still remembered, however, so you may re-enable the adjustment by giving one or
              both commands.  The NOMINAL and ACTUAL arguments may  be  for  any  time  zone,  as
              seesat5 cares only about their time difference.

       NULL   This  command  is  useful  if  you want to specify year, month day and time for the
              start/stop/span commands but don't want to do the RUN command automatically. It can
              save specifying repeated information on every line of your parameters.

                  Example :
                  open my.tle span 720 null
                  start 1993 oct 01 1900 runall
                  start 1993 oct 02 1900 runall

       OFFSET <time>
              Applies  an  offset  to  the  epoch  of  the satellite elements, thereby making the
              satellite come early or late in the predictions.  Useful for  putting  a  satellite
              ahead  of or behind schedule, to evaluate the resulting track drift with respect to
              the stars.  Also can be used to adjust for any discrepancy noted between  predicted
              and  actual  times  of  passes.   A negative sign is allowed on <time>.  A negative
              <time> will make the effective epoch EARLIER, and make the satellite  come  EARLIER
              in  your predictions.  If OFFSET is nonzero, an advisory of its value is printed at
              the top of each prediction table.  OFFSET is reset to zero when an element  set  is

       OPEN <filename>
              Opens the orbital element file.  If an element file is already open, that file will
              be closed first.OPEN builds an index of the satellites in the  file,  using  linked
              blocks  in RAM.  Each block holds 50 satellites.  Storage is requested as needed at
              run time, so the size of the element file is  limited  only  by  available  memory.
              Assuming your system uses 4-byte longs and 2-byte pointers, each 50-satellite block
              uses 1352 bytes.The index only contains the name of the satellite and its  location
              in  the  file.  The elements are not read from the disk until you issue the LOAD or
              NEXT command.

              This command requires a file name parameter that will  open  a  STANDARD  DELIMITED
              FILE with that name. The file format is as follows:

                  1st. record
                  "satellite","date","time", ...

                  2nd. record thru EOF
                  satellite name

              This  a value that has a default of 60 minutes. This is used in the RUNTIME mode to
              determine how long to keep a satellites above horizon values in memory before  they
              are  deemed un-useable. The way the RUNTIME mode works is that it does a prediction
              for a satellite. If that satellite is above the horizon at a particular time,  that
              time  is  saved  in  memory.   When  the  satellites  other  attributes (elevation,
              magnitude etc) are checked and they pass the conditions, the stored time values are
              used  to  start  printing  the prediction run. If the satellite never satisfied the
              selection conditions, then after 60 minutes has passed, the stored time values  are
              reset. This prevents misleading prediction data being printed.

       PARA <date time>
              Print  the  parallactic  angle  at  the predicted position of the satellite for the
              given time.  Parallactic angle is the direction of celestial north, as  seen  in  a
              binocular  field  of  view.   E.g.,  0 = straight up, 90 = 3 o'clock.  This command
              allows you to examine your star atlas plot and visualize the star field orientation
              you'll see when you go outside.

       PRECESS <date time>
              Controls the correction of Right Ascension and declination for precession.  PRECESS
              sets the final epoch.  The epoch of the elements is  always  used  as  the  initial
              epoch.  For 1950.0 or 2000.0 coordinates, respectively:

                  PRECESS 1950 JAN 0 2210
                  PRECESS 2000 JAN 1 1200

              These  are  Greenwich  times,  so, strictly speaking, the PRECESS command should be
              given before setting ZONE.  But for  all  practical  purposes  it  doesn't  matter.
              Precession  is  so slow there will be virtually no error even if you miss by a full
              year.  Over several decades, though, it will build up to a significant level.   For
              example,  if  your atlas is 1950.0 and you neglect the PRECESS command, an error of
              up to 42 arc minutes can occur in your  plot  of  a  satellite's  track.   This  is
              perhaps  four  or  five  times  worse  than SEESAT's prediction accuracy under good
              conditions!  The PRECESS value remains until you change it or exit SEESAT.  Default
              setting is 2000.0 at program startup.

              This  will  run the current parameters and conditions for each satellite in the TLE
              file,  and  display  results  whenever  a  satellites  data  passes  the  selection
              conditions.  It  then  increments  the  time by 1 minute and re-runs the prediction
              again. This will continue forever or until a key is pressed.

              The START command must be done first to setup  the  date  and  time  at  which  the
              prediction  starts.  This  is  the  raw  data  generator for the realtime graphical
              display and also gives you in time order, the satellites you may be able to see.

       PRINT? If the last prediction run resulted in a line of data being  printed,  execute  the
              command  to  the  right of PRINT?.  Otherwise, skip it.  There must be at least one
              command after PRINT?.

              This command is used to limit the number lines  printed  per  satellite  prediction
              when  running  in the RUNTIME mode. The reason you may want limit the lines printed
              is because of very slow moving or stationery satellites. The RUNTIME mode  normally
              prints  prediction data until the satellite dips below the horizon. Of course, some
              satellites never dip below the horizon so end up with either a  lot  of  prediction
              data  or  the  program  just keeps printing the data forever. I had coded a default
              value for the printlimit of 60 lines. This default is fine for most  regular  runs,
              but for some special purpose runs you may want to change it.

       RET    If  encountered  in  a  batch  file, returns control to user.  If entered manually,
              resumes execution of the batch file.

       REPEAT Jump back to beginning of command line.

       REPORT This command is used to suppress printing of lines that come from  the  SEESAT5.INI
              file. It requires a 0 or 1 as a parameter. The default is to suppress (value 0). If
              you want to see all command lines and messages printed, set the report option to 1.
              Messages  like  "complete; nn satellites found" are suppressed. More message may be
              suppressed by this command in the furure.  This just helps to 'clean' the output to
              just the interesting satellite data.

       RUN    Begin  a  prediction  run,  using  the  current  time parameters.  The START, STOP,
              CENTER, SPAN, or STEP command automatically begins a run if it is at the end of the
              command  line.  That is the normal way to get a run.  The RUN command is convenient
              if, for example, you load a new element set and want a run  without  changing  time

       RUNALL This  command  is  almost  a combination of OPEN, NEXT, RUN and REPEAT. It takes no
              parameter values or filenames. It will reposition the current TLE files pointer  to
              BOF, read thru each two line element set, do the RUN command on it and repeat until
              all elements in the file have been read. The difference between  this  command  and
              the  commands  it replaces, is that it carries on processing the next input command
              after all two line elements have been  processed.  The  NEXT  RUN  REPEAT  commands
              unfortunately  stops  the  entire run as soon as it reaches the end of the elements
              file. I use this to generate a list of all satellites that I can see each  day  for
              the whole of the month!

                  Example :
                  open my.tle
                  start 1993 oct 01 1900 span 720 runall
                  start 1993 oct 18 1900 span 720 runall
                  start 1993 oct 31 1900 span 720 runall

       RUNDBS Like  RUNTIME  but  only  runs  the  satellites in your database.  You can still do
              RUNALL or RUNTIME any time to run all the satellites loaded with your last OPEN.

              This runs prediction in time order. This produces the exact same output data as the
              RUN  command  except  it  is in time order. It does however take a little longer to
              run. The processing involved in this command is  to  run  through  every  satellite
              looking  for  a  satellite  that is above the horizon at a particalur instance. The
              instances starts at the start time and continues until the stop  time  is  exceeded
              with an increment of the step.

              When  a  satellite  is  found  that  is  above the horizon and it also satifies the
              selection conditions, its data is printed until it dips below the horizon. At  that
              time the printing stops and the next satellite in the input TLE file is processed.

              For  Geo  Stationary  satellites  the  parameter  PRINTLIMIT comes into play.  This
              allows you to stop the printing of data when a certain number of  lines  have  been
              printed.  If  this command was not present, the data print would print forever if a
              geo-stationary satellite ever passed all the selection conditions.

              This command requires NO parameter, it just closes the last opened SDF file.

       SKIP   Skip the command to the immediate right of SKIP.  To be used following  PRINT?,  to
              reverse the test.  There must be at least one command after SKIP.

       SPAN   Followed  by  a time in minutes, this command determins the length of the data run.
              When used with the CENTER command the time value is centered on this time.

       START  Defines the start time for the run. Requires a date and a time as parameters.

       STEP <time>
              Controls size of time steps in  the  prediction  run  in  minutes.   A  run  begins
              automatically if STEP is the last command on the line.

       STOP   Defines the stop time for the run. If only a time is specified, the start date will
              be used. Accepts a date and a time as parameters.

              These commands require an integer and a time. The integer is when you want to  stop
              (start)  the  prediction  in number of days from today, followed by a time that you
              want to stop (start).  Just for consistency, the TODAY  command  can  now  also  be
              specified as STARTDAY.

              This  command  will  show  a selected summary data about the last TLE file that you
              OPENed. At present it shows the satellites that have the earliest and latest  epoch

       SUN <date time>
              Print the azimuth & elevation of the sun at the given time.

       TODAY  This  commands  automatically  sets  up  todays date as the default START date. The
              command must be followed by a number indicating how many days you want  to  add  to
              the  system  date as the START value.  This number may be zero or an integer number
              of days.

                  Example :
                  OPEN NASA.TLE
                  TODAY +0 1700 STOP 2300 RUNALL
                  TODAY +1 0400 STOP 0800 RUNALL

              gives tonight and tomorrow  mornings  satellite  viewing  data.  This  command  was
              implemented  because  it  saves  changing  SEESAT5.INI every day to run nightly and
              morning predictions.  You can set up the similar parameters as the  example  above,
              depending on when you do your regular/daily prediction run.

       ZONE <time>
              Set  timezone to that at the viewing location in UTC. A negative sign is permitted.
              E.g., for Pacific Standard Time:

                  ZONE -800  or
                  ZONE -0800

              The ZONE value need not be an integral number of hours, e.g., Newfoundland standard
              time is 3h 30m behind UTC:

                  ZONE -330

              Default ZONE at program startup is Greenwich time.

       The  following  commands  are  used  for  entering  orbital  elements  when no tle file is
       available for the satellite in question.

       AOP <number>
              Number represents the argument of the perigee.

       B <number>
              Number represent the BSTAR value.

       E <number>
              Number specifies the eccentricity of the orbit

       EPOCH <epoch>
              Manually  enter  epoch  of  the  orbital  elements.   Must  be  in  NORAD   format:
              YYDDD.DDD... (use any number of decimal places).  Unused digits in the integer part
              of day number must be padded with spaces or zeros.  If spaces are used for padding,
              the number must be enclosed in quotes.

                  EPOCH 91003.52029891    or
                  EPOCH "91  3.52029891"

       I <number>
              The number stands for the inclination of the orbit.

       MA <number>
              This number specifies the mean anomaly.

       MM <number>
              Mean motion is determined by the value of number.

       MMDOT <number>
              This number represents the first derivative of the mean motion. Note: this value is
              not used in the SPG4 model used by seesat5 and is only retained  for  compatability
              with the older SPG model

       MMDOTDOT <number>
              The  second  derivative  of the mean motion is specified by this number. Note: this
              value is not used in the SPG4 model used  by  seesat5  and  is  only  retained  for
              compatibility with the older SPG model.

       NAME <satellite name>
              Satellite  name  will  appear  in  the  printout for the current element data being
              loaded by the above commands.

       RAAN <number>
              This number specifies the right ascension of the ascending node.


       seesat5(1), SEESAT5.INI(5), tle(5), cr(1)


       Many of the above commands "do not work well with others" so some unexpected behavior  may
       result at times. Please report any suspected bugs to Dale Scheetz <>.