Mitsubishi SRRM25ZE, SRRM60ZE, SRRM35ZE, SRRM25ZF-S, SRRM50ZE User Manual
...
Updated for Gpredict 1.2
by Alexandru Csete OZ9AEC
Gpredict User Manual
Copyright © 2001-2009 Alexandru Csete and Contributors. All rights reserved.
This document is free; you can redistribute it and/or modify it under the terms of the
GNU General Public License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This document is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details.
You should have received a copy of the GNU General Public License along with this
document; if not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.
Revision History
Date Issue Notes
12 Oct 2010 1.2 Updated for Gpredict 1.2
5 Oct 2009 1.1 Updated for Gpredict 1.1
24 May 2009 1.0 First official issue released with Gpredict 1.0
Table of Contents
1 Introduction.....................................................................................................7
1.1 What is Gpredict?.............................................................................................................7
1.2 Features of Gpredict......................................................................................................... 8
1.3 About this Document........................................................................................................ 8
1.4 Your Feedback is Appreciated.......................................................................................... 9
2 Getting Started with Gpredict.......................................................................11
2.1 The Basic Idea................................................................................................................ 11
2.2 The Module Pop-Up Menu.............................................................................................. 13
2.3 Configuring the Module..................................................................................................14
2.3.1 Setting Up the Ground Station................................................................................15
2.3.2 Selecting the Satellites............................................................................................ 16
2.3.3 Module Properties................................................................................................... 17
2.4 Creating a New Module.................................................................................................. 19
2.5 Predicting Satellite Passes............................................................................................. 19
2.5.1 Upcoming Passes for a Satellite..............................................................................19
2.5.2 The Sky at a Glance................................................................................................. 20
2.6 Moving On...................................................................................................................... 21
3 Customising Gpredict....................................................................................23
3.1 Overview......................................................................................................................... 23
3.2 Number Formats ........................................................................................................... 25
3.2.1 Show Local Time Instead of UTC............................................................................25
3.2.2 Time Format............................................................................................................ 25
3.2.3 Geographical Coordinates....................................................................................... 28
3.2.4 Measurement Units................................................................................................. 28
3.3 Ground Stations.............................................................................................................. 28
3.4 TLE Update..................................................................................................................... 30
3.5 Message Logs.................................................................................................................30
4 Modules and Views........................................................................................31
4.1 Data Fields...................................................................................................................... 31
4.2 Views.............................................................................................................................. 32
4.2.1 The List View...........................................................................................................32
4.2.2 The Map View.......................................................................................................... 33
4.2.3 The Polar View........................................................................................................36
4.2.4 The Single-Satellite View........................................................................................39
4.2.5 The Upcoming Passes View.....................................................................................40
5 Advanced Pass Predictions............................................................................41
5.1 Customising the Prediction Parameters.........................................................................41
5.1.1 Pass Conditions....................................................................................................... 41
5.1.2 Multiple Passes....................................................................................................... 42
5.1.3 Single Pass.............................................................................................................. 44
5.2 Sky at a Glance............................................................................................................... 44
5.3 Communication Windows...............................................................................................45
5.4 The Advanced Predictor................................................................................................. 45
6 Updating the Orbital Elements.....................................................................47
6.1 Overview......................................................................................................................... 47
6.2 Automatic Update from the Internet.............................................................................. 48
6.2.1 Auto-Update............................................................................................................48
6.2.2 Update from the Internet........................................................................................ 49
6.3 Semi-Automatic Update from Local Files.......................................................................50
6.4 Manual Update............................................................................................................... 50
7 Controlling Radios and Rotators...................................................................51
7.1 Overview......................................................................................................................... 51
7.2 Hamlib Tutorial............................................................................................................... 52
7.2.1 Rigctl....................................................................................................................... 53
7.2.2 Rotctl....................................................................................................................... 55
7.2.3 Rigctld and Rotcld................................................................................................... 55
7.3 Configuring your Devices in Gpredict............................................................................56
7.3.1 Radio Configuration................................................................................................57
7.3.2 Antenna Rotator Configuration...............................................................................58
7.4 Controlling your Devices with Gpredict..........................................................................59
7.4.1 The Radio Control Window...................................................................................... 59
7.4.2 The Rotator Control Window................................................................................... 62
8 Creating Custom Layouts..............................................................................67
9 Glossary.........................................................................................................69
List of Tables
Table 3.1: Most common format codes.................................................................................26
Table 3.2: The not so common time format codes................................................................ 27
Table 3.3: Examples of time format strings..........................................................................28
Table 4.1: Data field availability in the different views........................................................32
Table 7.1: Most common rigctl command line options.........................................................55
Table 7.2: Operating modes of the radio controller.............................................................. 62
Table 7.3: Operating modes of the rotator controller...........................................................66
List of Figures
Figure 1.1: Functional overview of a satellite tracking program...........................................7
Figure 2.1: The default main window showing a module with three views. ........................11
Figure 2.2: The four different layouts in gpredict................................................................12
Figure 2.3: The module pop-up............................................................................................. 13
Figure 2.4: The time controller window............................................................................... 13
Figure 2.5: The module configuration window.....................................................................15
Figure 2.6: The ground station editor window.....................................................................16
Figure 2.7: The module properties editor.............................................................................17
Figure 2.8: Satellite popup...................................................................................................19
Figure 2.9: Data presented about the next upcoming pass..................................................20
Figure 2.10: The sky at a glance...........................................................................................21
Figure 3.1: The preferences dialogue................................................................................... 24
Figure 3.2: The table showing the existing ground stations.................................................29
Figure 4.1: The list view illustrating the auto-sort feature...................................................33
Figure 4.2: The map view using the default settings............................................................35
Figure 4.3: The polar view....................................................................................................37
Figure 4.4: Polar View popup............................................................................................... 37
Figure 4.5: The single-satellite view.....................................................................................40
Figure 4.6: The upcoming passes view.................................................................................40
Figure 5.1: Parameters that control pass predictions..........................................................41
Figure 5.2: Configuration options for multiple pass predictions..........................................43
Figure 5.3: Configuration options for single pass predictions.............................................. 44
Figure 5.4: The sky at a glance.............................................................................................44
Figure 5.5: Configuration options for the Sky at a glance function......................................45
Figure 6.1: Configuration options for TLE updates..............................................................48
Figure 6.2: Selecting a directory to update the TLE data from............................................50
Figure 7.1: Radio and rotator settings..................................................................................56
Figure 7.2: Radio setup........................................................................................................ 57
Figure 7.3: Rotator setup..................................................................................................... 58
Figure 7.4: The radio control interface.................................................................................59
Figure 7.5: The rotator control interface..............................................................................62
Figure 8.1: A 3x3 layout grid................................................................................................ 67
Figure 8.2: The layout generated by the sequence 1;0;3;0;2;0;0;2;2;3................................68
1 Introduction
1.1 What is Gpredict?
Gpredict is a real-time satellite tracking and orbit prediction program. A
satellite tracking program is a computer program that predicts the position
and velocity of a satellite at a given time using a mathematical model of the
orbit. Once the position and velocity of the satellite is known other data can
be calculated, for example bearing, distance, footprint, and visibility just to
mention a few. Figure 1.1 shows a diagram of the core functionality of a
satellite tracking program.
Gpredict, like any other satellite tracking program, takes three kinds of
input:
1. Keplerian Elements describing the satellite orbit, as well as the
position and velocity of the satellite at a given time t0.
2. Position of the ground station on Earth.
3. The date and time at which the satellite position and velocity should
be calculated.
Given the data above, gpredict calculates the position and velocity of any
Earth orbiting satellite using the NORAD SGP4/SDP4 algorithms. These
algorithms solve Kepler's equation of orbital motion and apply various
corrections to compensate for irregular effects like the shape of Earth and
gravitational influence from other celestial bodies.
Gpredict has several ways of presenting the calculated satellite data to the
user. It can show the position, footprint (i.e. coverage area), and ground
track of the satellites on maps, it can show detailed satellite data in tables,
7
Figure 1.1: Functional overview of a satellite tracking program.
Gpredict User Manual
and it can also show the satellites within range on a polar plot (radar
screen).
The next section gives an overview of the features and functionality of
gpredict.
1.2 Features of Gpredict
● Fast and accurate real-time satellite tracking using the NORAD
SGP4/SDP4 algorithms.
● No software limit on the number of satellites or ground stations.
● Nice presentation of the satellite data using maps, tables and polar
plots (radar views).
● Allows you to group satellites into modules, each module having its
own visual layout, and being customisable on its own. Of course, you
can use several modules at the same time.
● Efficient and detailed predictions of future satellite passes.
Prediction parameters and conditions can be fine-tuned by the user
to allow both general and very specialised predictions.
● Allows you to track satellites in real time, simulated real time or
manual time control.
● Exhaustive configuration options allowing advanced users to
customise both the functionality and look & feel of the program.
● Automatic updates of the Keplerian elements from the web via HTTP
and FTP, or from local files.
● Support for automated ground station operation providing both
Doppler tuning for radios and antenna rotator control.
● Robust design and multi-platform implementation integrates
gpredict well into modern computer desktop environments, including
Linux, BSD, Windows, and Mac OS X.
● Free software licensed under the terms and conditions of the GNU
General Public License allowing you to freely use it, learn from it,
modify it, and re-distribute it.
1.3 About this Document
This document is intended to give a complete description of all the
functionalities in gpredict as seen from a user's perspective.
● Chapter 2 gives a quick introduction to the core functions and
features in gpredict. It introduces the concept of modules and views,
which are the key objects in gpredict. Reading this chapter should
make users able to perform real-time satellite tracking and some
basic orbit predictions using gpredict.
● Chapter 3 describes the top-level configuration options that allow
8
Introduction
users to customise the overall behaviour of gpredict.
● Chapter 4 gives a more in-depth description of the modules and the
views. It also describes how to customise each individual module.
● Chapter 5 describes the pass prediction functions in gpredict
including the pass condition parameters used by the prediction
engine.
● Chapter 6 describes how you can update the Keplerian elements for
the satellites in the gpredict database.
● Chapter 7 describes how to setup and operate gpredict with your
radios and antenna rotators.
1.4 Your Feedback is Appreciated
Both gpredict and this user manual is work in progress. Your comments,
questions and bug reports are highly appreciated. There is a web forum at
http://forum.oz9aec.net/ where you can discuss everything related to
gpredict and ask the community for help.
The gpredict website accessible at http://gpredict.oz9aec.net/ has more
information about other ways you can get support with your problems, or
how you can get in touch with the developers (see under User Support).
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2 Getting Started with Gpredict
2.1 The Basic Idea
The key idea in gpredict is the concept of modules. A module in gpredict is
the same as a document in a word processor application. It is an object,
which has a certain number of satellites and a ground station associated to
it. Based on the geographical location of the ground station and the current
time, the module calculates the positions and other data for the satellites
and displays it using various views organised in a layout.
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Figure 2.1: The default main window showing a module with three views.
Gpredict User Manual
When you start gpredict for the first time it opens a module called
Amateur. This module has a layout with three different views: A map view,
a polar view and a single-sat view see figure 2.1. Currently four different
views are available in gpredict:
● The List View shows the satellite data in a list/table having one
satellite in each row. It is well suited to present detailed information
about many satellites at the same time. The rows in the list view are
sorted automatically at run-time according to the selected sorting
criteria (e.g. elevation, next event, etc.).
● The Map View shows the satellites and their footprints (coverage
area) on a rectangular map. It is intended to give a quick overview of
which satellite is where at a given time. The map view can also show
the ground track of the satellites for several orbits.
● The Polar View, or radar view, shows the satellites within range on
a polar plot. The polar axis corresponds to the azimuth and the radial
axis to the elevation. It can be used to give you an idea of where to
“look” for a satellite.
● The Single-Satellite View can very efficiently show detailed
information about one single satellite. Its advantage over the list
view is that it is much more efficient, since it only shows one single
satellite.
● The Upcoming Passes View shows a list of satellites with a
countdown till next AOS/LOS for each satellite.
The module organises the views using a layout. The layout is based on a
two dimensional grid where data views (map, table, etc.) are placed by
specifying type and coordinates. Figure 2.2 shows the 2x2 grid used in the
default module.
12
Figure 2.2: The four different layouts in gpredict.
Getting Started with Gpredict
Section 2.3.3 will give you a more detailed description of data views in
predefined layouts and chapter 8 describes how to create custom layouts.
2.2 The Module Pop-Up Menu
Each module has its own pop-up menu, which can be accessed by clicking
on the V icon in the top right corner of the module. This pop-up menu gives
you quick access to the functions that are relevant for a module. A screen
shot of the pop-up menu is shown on figure 2.3.
The first two items in this pop-up menu are used to
change the display state of the module. A module can
be in three different states:
● Docked: In this default state the module is
docked into the notebook in the main window.
● Window: In this state the module is put in its
own window.
● Full-screen: In this state the module occupies
the whole screen.
You can freely toggle between these three states at
any time. Go ahead and try them if you haven't
already done so.
The next entry in the pop-up menu is Sky at a
glance. This function is intended to give you a quick
overview of which satellites are up now and which
satellites will be up during the next 8 hours. This
function is described in section 2.5.
The Time controller menu item
pops up a small window (see figure
2.4) containing widgets for
controlling the time of the module. By
default, the module will run in realtime, but using the Time controller
you have the possibility to tun in
simulated real-time or manual time
control.
The horizontal slider below the
calendar allows you to quickly pan
back and forward in time ± 2.5 hours
from the current time.
The arrow buttons in the time
controller determine in which direction the time should run. The Throttle
value determines the
time compression factor
. A throttle value of 1
corresponds to 1 second / second (real-time), a value of 2 corresponds to 2
seconds / second (simulated real-time), etc. The Pause button between the
two arrow buttons stops automatic increment of time and you can set the
module time using the date and time controls in the window. The Reset
13
Figure 2.4: The time controller
window.
Figure 2.3: The
module pop-up.
Gpredict User Manual
button will reset the time to the current time provided by the operating
system.
The Radio Control and Antenna Control menu items bring up the radio
and antenna rotator controller windows. Setting up gpredict to perform
Doppler tuning of radios and antenna rotator tracking is described in
details in chapter 7.
The Configure item allows you to customise the module. This function is
described in the next section.
The Clone... menu item is a convenience function to create an exact copy
of a module. If you select it a small dialogue window pops up asking you to
enter a name for the new module. Enter an appropriate name. Note that
only standard ASCII characters consisting of 0..9, a..z, A..Z, hyphen (-) and
underscore (_) are allowed. This is because the name of the module is also
used for naming the data file in which the configuration will be stored. If
you clear the check box asking whether to open the module, the new
module will be created and that's it. If you leave the check box checked, the
new module will be opened right after it is created. Leave the check box
checked and press OK.
You should see your new module appear in the notebook as a new page. A
key feature in gpredict is that you are allowed to use several modules at
the same time. There is no limit on the number of open modules, except the
processing power and available memory of your computer. It is also up to
you how many modules should be docked in the notebook and how many
should be in their own window. Needless to say, only one module can be in
full-screen state at the same time.
The last two menu items in the pop-up menu, Delete and Close, do exactly
what they promise. If you select Delete the module will be closed
immediately and you will be prompted to confirm the deletion. This is your
last chance before the module is completely removed from the disk.
A module can also be closed by clicking on the X icon in the top right
corner.
2.3 Configuring the Module
If you have followed the cloning instructions in the previous section, you
now have two copies of the same module. Lets modify one of them so that
they are not exactly identical. Gpredict offers you the possibility to
configure each module independently of the others. This is not a
requirement, it is an option. It is up to you whether you want to use the
global defaults or whether you want to customise each module to suit your
needs, and this applies to all parameters.
To configure a module select the Configure menu item in the module popup menu. This will bring up a small dialogue window showing the module
name, the name of the ground station, and which satellites are tracked in
this module. Figure 2.5 shows a screen shot of the module configuration
window.
Note that you can not change the name of a module here. If you want to
14
Getting Started with Gpredict
rename a module, create a clone and then delete the original.
2.3.1 Setting Up the Ground Station
Below the module name you will find the name of the ground station, i.e.
the geographical location that is used as reference point in the
calculations. It is important to define the position of the ground station
accurately since this it is one of the key input parameters in gpredict. The
sample module uses a ground station called
sample
, which defines a place
in Denmark.
To add your own ground station, click on the + button located right of the
ground station name. This should pop up a small dialogue window as shown
on figure 2.6 where you can enter the data for your ground station. The
only required parameter here is the Name, which you have to enter
according to the same rules as the module name. Optionally, you can also
enter a Description and the Location name, the latter could be a
combination of the city and the country of the location.
15
Figure 2.5: The module configuration window.
Gpredict User Manual
For your convenience gpredict offers you the possibility to select a location
from a predefined list. The list can be accessed via the Select button right
next to the Location field. This is useful if you have no idea of the
geographical coordinates of your location. In that case you can simply
select the nearest city from the list.
Instead of entering the latitude and longitude of your location, you can also
enter the Maidenhead locator grid square in the Locator field. Doing so
will automatically update the latitude and longitude fields.
When you are done, click OK to return to the module configuration. Your
newly created ground station should be selected as location for this
module.
2.3.2 Selecting the Satellites
Next step in the module configuration is to select which satellites should be
tracked in this module.
The satellites currently tracked by this module are listed in the right side of
the configuration window while the available satellites that can be tracked
are listed on the left side of the window. You can move a satellite from one
list to the other by double-clicking on it or by clicking on the arrow buttons
between the two lists.
Gpredict has approximately 1200 satellites in its database that you can
choose from. To help you locate a specific satellite, you can use the Search
field as well as the Group filter located above the list of available satellites.
When you start typing a satellite name I the Search field, Gpredict will
search as you type and highlight the satellite that matches your search.
The search is case insensitive.
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Figure 2.6: The ground station editor window
Getting Started with Gpredict
You should be careful not to select too many satellites
for one module, otherwise your module may become
clumsy. Too many satellites may also decrease the
performance in particular if you are using a map view.
Up to 10-15 satellites per module seems to be a good
number, maybe less if you use the map view.
2.3.3 Module Properties
In order to edit the look and feel of the module click on the Properties
button. This will bring up a window showing the module properties
grouped in a notebook. Figure 2.7 below shows a screen capture of the
module properties editor.
The Layout page allows you configure the visual appearance of the
module. You can choose between nine predefined layouts or create your
own custom layout by specifying the layout code. The different views are
explained in greater detail in section 4.2 and a description of how to create
your own layout is in chapter 8.
17
Figure 2.7: The module properties editor.
Gpredict User Manual
The Refresh Rates page allows you to tune how often the module should
perform the calculations, as well as how often the views should be updated.
The data refresh rate is specified in milliseconds. This is the time between
two calculation-cycles. Every cycle the module will recalculate the data for
all satellites associated to the module. The refresh rates for the views are
specified in integer cycles of data refresh. If the data refresh rate is 400
msec and the list view refresh rate is 2 cycles, the list view will be
refreshed every 800 msec.
The map and the polar view do not need to be refreshed very often. For
these views visible changes will normally occur over 3-4 seconds. The list
and the single-satellite view, on the other hand, looks pretty cool when they
are refreshed every 100-200 msec, but be careful with the CPU load, in
particular if you have many modules open at the same time.
The rest of the pages in the module property editor define the look and feel
of the views. Most of the parameters are self-explaining and you should not
be afraid of experimenting with the different settings. If you somehow end
up with a useless configuration, you can always reset to the default values
by clicking on the Reset button that is available on all pages.
Chapter 4 describes the modules in more details and also gives a detailed
description of the configuration parameters.
18
Getting Started with Gpredict
2.4 Creating a New Module
In order to create a new module, select File → New Module in the menu
bar. This will bring up the same dialogue as you saw while customising an
existing module in the previous section (see figure 2.5), except that here
you have to enter a new name for the module.
Besides the name you will also need to select the observer location and the
satellites you wish to track with the new module. Of course, you can also
customise the new module as described in the previous section.
When you are finished, click OK and the new module will open in the
notebook.
2.5 Predicting Satellite Passes
2.5.1 Upcoming Passes for a Satellite
In order to predict satellite passes occurring in the
near future, you have to right-click on a satellite in
any view. This brings up a pop-up menu for the
selected satellite, and in this pop-up menu you can
select either the Show next pass or the Future
passes menu item. Figure 2.8 shows how the
satellite pop-up menu looks like when you right
click on a satellite in the map view. The satellite
popup for other views look slightly different;
however, there will always be two menu items for
predicting the upcoming passes.
The Show next pass function gives you detailed
information on the first coming pass including the
azimuth, elevation, range and footprint during the
course of the pass. The data is shown in a table as well as on a polar and an
Az/El plot, see figure 2.9. You can configure gpredict to show other data in
this dialogue, select Edit → Preferences and go to the Predict → Single
Pass page. Section 5.1 contains more details on how to customise and finetune the future pass prediction engine.
19
Figure 2.8: Satellite
popup.
Gpredict User Manual
The Future passes function gives you an overview of up to the next 10
passes occurring within the next 3 days. The information you are given is
the rise time (AOS), the set time (LOS), the duration, maximum elevation
and the azimuth at AOS and LOS. Again, all parameters including the
number of passes to predict can be customised via the Preferences
dialogue.
If you double-click on a row in the Future passes dialogue, a new window
pops up showing the details for the pass you have clicked on. This is the
same window as you saw when you selected the Show next pass function,
but the pass details are now for the selected pass in the future, which is not
necessarily the first coming pass.
The data displayed in the pass prediction dialogues is static. This means
that the shown data will not be updated automatically if you leave the
dialogues open. You will have to request a new prediction as described
above.
You may have noticed that the above mentioned pop-up
menu does not come up if you right-click in the singlesatellite view. To bring up the pop-up menu in the
single-satellite view you should click on the V icon right
next to the satellite name.
2.5.2 The Sky at a Glance
The sky at a glance is a convenience function in gpredict that can show you
a quick overview of what satellite passes you can expect at your location
between now and the next X hours. An example is shown on Figure 2.10
below. You can activate this function via the module popup menu and there
are more details about configuring this function in chapter 5 – Advanced
Pass Predictions.
20
Figure 2.9: Data presented about the next upcoming pass.
Getting Started with Gpredict
2.6 Moving On
If you have read through this section carefully you should have a good
understanding of the basic functions in gpredict as well as some
understanding of how they work. The following chapters of this manual will
continue with more detailed descriptions of all functions in gpredict, some
of which have not been covered in this introductory section. Once you get
used to the basic functionalities in gpredict you should definitely go on and
read the rest of the manual, too. Have fun!
21
Figure 2.10: The sky at a glance.
3 Customising Gpredict
3.1 Overview
On one hand, gpredict tries to be very simple and easy to use not requiring
any lengthy configuration and set-up procedures (runs out of the box). On
the other hand, gpredict tries to let the users customise the look and feel of
the application down to the lowest details. Some people would say that
these two requirements contradict one another, nevertheless, they have
been the key drivers during the design and development of gpredict.
Consequently, gpredict has two customisation levels:
1. The Global Settings define the behaviour of gpredict as a whole
and also provide default values for the modules. These settings can
be accessed from the main menu bar via the Edit → Preferences
menu item.
2. Module Level. These settings allow the user to customise each
module independently of the others. They are accessed via the popup menu of each module: Configure → Properties.
The preferences dialogue for editing the global settings is shown on figure
3.1. If you compare it with the module properties editor you saw in the
previous chapter you will notice that the module properties dialogue is
simply a subset of the global preferences dialogue. In other words, the
global configuration dialogue contains the module properties dialogue, and
the settings in the global preferences dialogue provide the default values
for modules, where there are no specific user settings.
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