--- Basic tracking parametersThe primary page contains the basic tracking parameters like the nominal antenna position or the mayor tracking mode. This page also gives access to the logging and analysis tools built into the tracking device. The most important parameters are explained below:satellite name: This ist the name of the satellite as it appears in the list of stored targets. When you read in ephemeris data which contains a satellite name, the latter gets copied into this field. You may however enter any other name.nominal orbit: With this parameter the satellite's nominal orbit position is specified. There are two applications for the nominal orbit value in the software: The tracking device is capable to evaluate the antenna pointing angles for the orbit position, you may move the antenna to the resulting position in order to find a new satellite quickly. Also the orbit value is used to identify and sort satellites in the target list.The nominal orbit position has to be entered as 'deg. east' To specify a satellite at 10° West, either enter -10.0 or 350.0, the software accepts both notations.tracking mode: With this parameter you select the major tracking mode. Available modes are:
- STEP --- Plain step track mode.
- ADAPTIVE --- Step track with mathematical model assistance / backup.
- PROGRAM --- Program track following given ephemeris data. interval: Defines the overall tracking interval. The tracking device performs it's steps not faster than defined with this parameter. If an optimization step takes longer than this interval, this is not treated an a fault. The tracking device will start the next step immediately after the first one has finished. Set this value to 0 in order to force the tracking to operate at a maximum rate.The effective duration of one optimization step primarily depends on the integration times and delays defined with the advanced step track parameters. But also the fluctuation of the beacon level reading has an impact to the duration of a tracking step. If the standard variation of the readings will exceed a configurable threshold, the tracking algorithm will try to repeat the measurement several times.az/el nominal: These fields define the nominal position of the antenna for this satellite. The nominal position is the center of the box in which the antenna tracks the satellite. The size of this box is set on the 'advanced tracking parameters' page described below. The nominal position also is that one the antenna moves to, if the satellite's tracking settings get recalled from a preset memory.Changing one of the nominal position values while the tracking mode is 'OFF' immediately moves the antenna to the given position. With tracking enabled, changing a nominal position value does not move the antenna, only the box limits are shifted accordingly.polarization: The polarization value directly controls the antenna's polarization offset motor (if available). None of the tracking algorithms changes this value, in must be optimized manually when a satellite is going to be tracked the first time.beacon frequency: This parameter controls the beacon receiver's receive frequency. The true RF receive frequency value is required, not an L-band frequency. It is necessary to enter this value even if the beacon receiver is not controlled by the tracking M&C system. This is because the tracking engine uses the beacon frequency to compute the tracking step sizes.beacon pol.: With beacon receivers which are capable to switch the input polarization, this parameter permits to select the polarization plane of the beacon to receive.Y/T PLOT: Clicking to the 'Y/T PLOT' button opens a window which shows a diagram of the antenna movement and the beacon level over the time. If you leave this window opened, it gets updated with each tracking step the antenna makes. See the paragraph 'built in analysis tools' below for further information.X/Y PLOT: Clicking to the 'X/Y PLOT' button opens a window which shows a diagram of the antenna movement in both axes. If you leave this window opened, it gets updated with each tracking step the antenna makes. See the paragraph 'built in analysis tools' below for further information.STEP LOG: Clicking to the 'STEP LOG' button opens a window where the program shows a live report what the tracking engine actually is doing. The log in this window is cleared with each new tracking step. If 'Y/T PLOT' diagram shows many unsuccessful tracking steps, watching the 'STEP LOG' reports may give an explanation why the tracking engine discards so many steps.RESET POS: Moves the antenna back to it's nominal position.RESET MEM: Clears the tracking memory used by the ADAPTIVE tracking mode.orbital model: Displays the type and age of the orbital model used by the PROGRAM tracking mode. While in ADAPTIVE tracking mode 'ADAPTIVE' is displayed.operation state: Reports the actual operation state of the tracking engine. This mainly reflects the major tracking mode, but also contains some additional information, e.g. which type of ADAPTIVE model the tracking engine actually uses.tracking step: Reports the tracking step which recently has been done. This exactly matches the last line of the 'STEP LOG' display.tracking offset: These fields report the actual offset of the antenna pointing from the nominal position.beacon level: Displays the beacon level as actually read from the beacon receiver.
--- Satellite listThe satellite list page permits to store tracking settings in a target memory pool which is unique to this instance of the Antenna-Tracking device. This is unlike the standard device preset function if the sat-nms software which stores device settings for all instances of one device type at a central place. The following functions are provided by this page:Save actual satellite: Clicking to this button stores the actual tracking parameters together with the nominal antenna pointing into a data file named after the actual satellite name followed by the nominal orbit position. If a file of this name already exists, it gets replaced.Delete seleted entry Deletes the selected (yellow colored) target memory file.Load selected parameters Loads all tracking parameters except the nominal antenna pointing from the selected target memory. This is intended to be used to copy the tracking settings from an already known satellite to a new one, which actually is being set up.Track selected satellite Loads all settings including the nominal antenna pointing and the tracking mode. Moves the antenna to the nominal pointing position and starts the selected tracking mode there.
--- Orbital modelAt this page you may define an orbital model for the satellite which is used with the PROGRAM tracking mode. The orbital model also may be used to find a satellite more precisely than by it's nominal orbital position.The tracking engine accepts either Keplerian elements in NASA 2-line format or Intelsat ephemeris data. The software automatically recognized the data format and chooses the appropriate orbital model. A common source for actual Keplerian ephemeris data is www.celetrak.com , weekly updated Intelsat orbital data may be found on the Intelsat web site.The easiest way to enter the orbital data to the tracking system is by copy & paste from the source web site. Clear the orbital data field, mark the desired orbital data in the web browser window and copy it into the orbital data entry field (use CTRL-C/CTRL-V on Windows based PC, the middle mouse button on Linux boxes like the sat-nms ACU indoor unit. For Intelsat data, copy the whole web page which shows the ephemeris data set. For Keplerian data copying the two lines containing the element data is required. When using data from Celestrak, you optionally may copy also the comment line above the element data, the satellite name will be adapted automatically in this case.Once you entered / copied the orbital data and change the input focus to another field, the software analyzed the data and updates the fields at the top of the page. The 'recognized orbital model' shows the type and age of the interpreted ephemeris data. The 'satellite name' and 'nominal orbit' are updated accordingly, if this information is present in the entered data. If you select the PROGRAM tracking mode on the primary parameter page, the antenna follows the position of the satellite as computed from the ephemeris data.Using the buttons below the orbital data entry field you may compute the actual antenna pointing either from the entered ephememeris data or from the satellite's nominal orbit position. Clicking to the large button at the bottom move the antenna to the computed position. This function is intended to be used to find a new satellite quickly. If there is no orbital data available for the satellite you search, you may enter it's nominal orbit position directly and compute the antenna pointing from this.The accuracy of the calculated antenna positions heavily depends on the antenna pointing calibration and on the accuracy of the antenna's geodetic location as defined with the configuration parameters.
--- Advanced step track parametersThis page contains a number of parameter which are used to tune the tracking algorithm. Most of these parameters affect the STEP and ADAPTIVE tracking modes as well.step size: This parameter controls the sizes of the search steps the tracking engine performs in the STEP and ADAPTIVE modes. With the step size set to 100%, the elevation test step is one half of the antenna's 1dB bandwidth. The azimuth step size is computed the same way, but divided by cos(elevation) to deskew look angle to the satellite. The antenna's beamwidth (approximately) is computed from the beacon frequency and the antenna diameter. A good initial value for the step size is 60%.settling time: The settling time is the time the tracking engine waits after it issued an antenna pointing command until it takes the first sample of the beacon level. Specially with small steps of the antenna position, the tracking engine has no real feedback when the antenna has reached it's final position. This delay time is used to ensure that the antenna pointing command has been executes and the beacon level has settled.step mode: In STEP mode, this parameter controls how the tracking engine selects the direction of a search step. With the SLOW step mode, search steps alternately are made in the one or the other direction. This step mode gives good results with satellites that move only a small amount. With the FAST step mode, each search step is made in the same direction of the last successful optimization step. With any unsuccessful step the direction changes. This mode is recommended to track inclined orbit satellites, because the tracking does not perform search steps against the satellite movement in the majority of cases. In the ADAPTIVE tracking mode, the tracking engine observes the step mode selection only as long as it cannot compute a usable model from the records steptrack data. Later it uses the the modeled antenna pointing to decide where to go for a search step.max optimization: The step track algorithm uses the measured beacon levels before a search step and after it together with some knowledge about the shape of the antenna beam to compute the peak location. Unexpected variations of the beacon level may disturb the measurement and may result to a wrong peak evaluation. To minimize the impact of this to the antenna pointing, the tracking algorithm limits the amount of an optimization step to this value. Setting this parameter to 0% forces the tracking engine to limit the peak position to a window between the antenna positions before and after the search step. Increasing the 'max optimization' parameter widens this window at both edges with the actual search step size multiplied by the 'max optimization' value.With the ADAPTIVE tracking mode this parameter is used, too. Here however it acts as a fault threshold: If a peak is outside, is is marked as invalid and not included to the tracking model computation.az/el search step: These fields show the actual search step sizes as absolute angles for you orientation. The fields get updated each time you change the 'step size' parameter.az/el window: These parameters define a rectangular window around the nominal antenna position. The tracking engine limits the optimization movements to this window.beacon averaging time: This parameter defines the time, while samples read from the beacon receiver get averaged to achieve one beacon level value. Recommended values are between 15 and 30 seconds, if the beacon receiver itself performs an effective averaging/smoothing of the level reading, shorter values may be possible.max standard deviation: While the program averages the beacon level readings, it also computes the standard deviation of the reading as a measure of the (short term) stability of readings. If the standard deviation exceeds this limit, the measurement is discarded.max signal drift: Before performing a search step, the tracking algorithm requires two beacon measurement series to differ not more than the value defined here. Otherwise the beacon level is assumed to drift, the search step is postponed or canceled.max drop in search step: If with a search step the beacon level drops more than the value set here, the antenna moves back to the previous or predicted position, no peak evaluation is done.min beacon level: If the measured beacon level falls below this value, a beacon level fault is risen and the measurement is marked as invalid. With the STEP tracking mode no tracking is performed until the beacon level is above the threshold again. In ADAPTIVE mode, the tracking engine tracks the satellite following the mathematical model made from the step track peaks.
--- Faults and fault maskBeacon receiver: The beacon receiver device states a fault. This may be a hardware fault or a loss of signal. It is recommended to switch of any level threshold monitoring at the beacon receiver and let the tracking device monitor the beacon level. The tracking device applies threshold monitoring only during the measurement phases, signal dropouts during the antenna movement phases are ignored.Beacon level: The measured beacon level is below the threshold set at the advanced step track parameters page.AZ/EL window limit: The recent step track peak found is outside the window limits set at the advanced step track parameters page. The antenna has been moved to the window limit rather than to the peak position. The fault stays active until the next tracking step.Antenna: The antenna positioning controller states a fault. This may be a motor failure, limit switch or another specific antenna fault.Search step size: The tracking engine is not capable to compute a valid tracking step size from the given data. This happen if either the antenna diameter (a setup parameter) or the beacon frequency is not set properly. The fault stays active until the missing value is set.AZ/EL Model match: In ADAPTIVE tracking mode, a tracking step found a peak which considered to be invalid at it is too far away from the position computed by the model. The fault stays active until the next tracking step.
--- The device info page.
--- The maintenance page. The configuration parameters described below are set at this page.
--- If this toolbar button is pressed, the diagram shows the search step and the beacon level change resulting from this as a dimmed peak at the left edge of each data point. You can easily monitor the signal degradation which is caused temporarily by the tracking search steps with this function enabled.
--- If this toolbar button is pressed, the diagram includes the evaluated peak positions. In STEP track mode, this actually is the location where the antenna gets moved to. In ADAPTIVE tracking mode, the antenna moves to the location resulting from the mathematical model which is computed from the step track peaks. In the latter case, the peak positions may be interpreted as the actual difference between the modeled pointing and the peak position.