Antenna
Bearing Tool Help
[Nov 2019]
Antenna Bearing Tool [ABT] is an alternative
to a magnetic compass for antenna installers to determine the required compass
bearing. ABT uses known landmarks as a reference bearing and the “offset” is
calculated.
ABT has two modes:
1. Cellular mode for “Base station Transmitter
Sites”. [BTS]
2. Point to Point mode for microwave
systems.
The land mark in either case must be visible
and identifiable.
NOTE: [BTS = Cell Phone Tower]
There are a many reasons for using this method
in preference to using a compass:
1.
Antenna
bearings are usually referenced to True North and it is a common mistake to
apply the correction for a magnetic bearing in the wrong direction, therefore
doubling the offset.
2.
In many
cases steel work or electric power sources affect the compass.
BTS MODE:
The principle of use is simple:
1.
The Icon
for the BTS is located on the map at the transmitting
site.
2.
The Icon
for the Land Mark is
located on the map at the land mark.
3. The desired antenna bearing [degrees true] is
entered via the pop-up keyboard. [Tap the text to
activate the keyboard entry]
4.
The two
lines on the map show the line to the land mark [RED] and the desired antenna
bearing.
You can then point the Red line towards the land mark and aim the
antenna along the Green line.
Alternatively the Offset can be read from the screen and a
protractor/theodolite used in place of the phone.
BTS Icon Location:
The BTS Icon can be located on
the map in four ways:
1. Touch/hold/drag the icon to
position
2. Enter the Latitude and Longitude
to the display via the keyboard. [Tap
the text to activate the keyboard entry]
3. Tap the “BTS Here” button. The icon will move to your current location
if you have GPS lock.
4. Tap the “Site List” button and the green Site List will be
displayed, covering the map. The map
info panel [Blue] remains visible.
Select a site by tapping on the record, name and
co-ordinates are shown on the green title bar.
Tap the “BTS/A-END” button, the icon will move to that
location.
The map info panel will update Site Name in the Blue title bar. The Longitude and Latitude displays will also
be updated.
Land Mark Icon Location:
The Land Mark Icon can be
located on the map in three ways:
1. Touch/hold/drag the icon to
position
2. Enter the Latitude and Longitude
to the display via the keyboard. [Tap
the text to activate the keyboard entry]
3. Tap the “Site List” button and the green Site List will be
displayed, covering the map. The map
info panel [Blue] remains visible.
Select a site by tapping on the record the name is then shown
on the green title bar. Tap the “LandMark” button, the icon will move to
that location.
The map info panel will update the Longitude and
Latitude. Site Name in the Blue title bar does not change.
Map Control
1.
The map centre can be moved by dragging, zoom is controlled by
two finger pinch.
2.
Click the “Map Type” button.
The map will toggle between Road Map and Satellite views.
3.
Click the “Auto Zoom” button.
The map will move and centre to show the icons.
Save
The “Save” button will save a
screenshot as a Portable Networks Graphic [png]
file. The user enters a file name
without the .png extension
Files
The “Files” button allows the
user to view and delete saved files.
POINT to POINT MODE:
Point to Point mode operates in
basically the same way as Cellular mode except that there are three icons: “A” end, “B” end and Landmark.
The offset is calculated from
the “A” end to “B” end bearing line. Path distance and “A” to “B” bearing are also
calculated.
Path distance can be displayed
in either kilometre or miles. The units
[Km/Mls] can be toggled by clicking on “PATH DIST”.
SITE LIST:
The following describes the Site List
functions:
“Site List” button
in the Blue section will show the Site List.
Initially the Site List has a number of entries; these are fictitious
sites for demonstration purposes only.
Delete these after you have entered at least
one location of your own.
“Store” button takes
the Site Name from the title bar of the Blue panel and the Longitude and
Latitude of the BTS/A-END and stores this as a new entry in the database. This new entry is immediately displayed in
the site list in alphabetical order.
[NOTE:
The selection of BTS or A-END data depends whether the App is in BTS
mode or End to End mode.]
“BTS/A-END” button moves the BTS/A-END icon on the map to the site entry selected
in the Site List. To select a site from
the list tap the entry and the Site Name will be displayed on the Green title
bar.
When the “BTS/A-END” button is tapped the
BTS/A-END icon moves to the selected location on the map.
“LandMark” button moves the Land Mark icon to the
selected location on the map.
“Del” button removes the selected entry from the database and the site
list.
Before deletion the Site Name, Longitude and
Latitude details are transferred to the map information [Blue], if the deletion
was an error, tapping the “Store” button
will restore the entry to the database.
“Imp” button is
used to import a site list, this import will overwrite the existing data and
existing records will be lost.
The user must first copy a CSV file of list into the
ABT folder on the phone.
The CSV file would normally be generated from a spread
sheet or database and must be named “impsitelist.csv”.
The CSV file must be based on three columns, Site Name,Longitude,Latitude.
Headers are optional and will not affect the import.
“Imp+” button
is similar to the “Imp” button but does not overwrite the existing data. The imported list is appended to the existing
data; if there are duplicates they are deleted.
A record is only seen as a duplicate if ALL data
matches. EG If there are two records
with the name, “London”, but with different Latitudes they will not be seen as
duplicates.
“Exp” button is used to export the current Site List as a
CSV file to the ABT folder. This file is
named expsitelist.csv and has no headers.
“?” button displays a quick info file: exit by using the phones back
button.
SEARCH FUNCTION: Tap on the Green Title Bar
and edit the Site Name. As the text
changes the site list will scroll to the closest match, the more of the name
typed the closer the match.
End the search using the keyboard return key.
SUNDIAL:
The Sun Dial function is a “Last
Resort” option when operating in an environment with no identifiable land
marks. [Deserts, snowfields]
This function is turned on/off
with the Sun Dial button at the bottom left corner of the map. A sun symbol, a shadow line are displayed and
the map is rotated. With the device in
the horizontal, the sun symbol is pointed towards the sun [as a land mark] and
the antenna bearing line is aligned correctly.
Alignment with the sun can be
eased by placing a small object [inverted golf tee, pencil stub, etc.] to act as
a gnomon.
NOTE1: This method ceases to be
valid at less than 24degrees from the equator; this function will not work at
these latitudes.
NOTE2: This method may be useful
if orienteering through mountains in iron ore country.
MECCA:
The MECCA function uses the
Point to Point mode to show the direction of Mecca from the user’s current
location. The Mecca button is initially
not shown. The button is activated from
the Settings menu.
When activated the Mecca button
is located at the bottom right corner of the map. A click on the button will centre the map on
the current location, the green line points toward Mecca. A second click on the Mecca button restores
the previous screen.
End of File