CloudRF.com Page 1 of 18 Copyright 2013 Farrant Consulting Ltd Keyhole Radio user guide Documentation Version 5.0 1 Introduction 1.1 System overview 1.2 Concept of operations 1.3 Accounts and login 2 Operation 2.1 User interface 2.2 Calculate options 2.3 Transmitter options 2.4 Antenna options 2.5 Receiver options 2.6 Environment options 2.7 Layer options 2.8 Path Profile Analysis 3 Data 3.1 Terrain data 3.2 Radio templates 3.3 Antenna templates 3.4 Ground clutter 3.5 User archive 4 Miscellaneous 4.1 Linux compatibility 4.2 Repeater chaining 4.3 Exporting results 4.4 Performance tips 5 Examples 5.1 Push to talk VHF radio 5.2 Mobile phone mast 6 Technical support 6.1 Trouble shooting 6.2 Frequently asked questions [email protected]1 Introduction 1.1 System overview Keyhole Radio is a unique and powerful radio planning plugin for Google earth™. The software is server based meaning end users only need to open a Keyhole Markup Language (KML) overlay in Google earth to use it. It's ideal for organisations already using Google earth as it can be deployed effortlessly to users as a URL and the KML output is visualised along with existing data layers as a common operating picture (COP). The system’s terrain data, radio templates, antenna patterns and ground clutter are all managed server side so the client only needs Google earth and a network connection. A user account is required to use the service. 1.2 Concept of operations The software acts as a plugin to Google earth. To open it, either launch the KML file from cloudrf.com or add a ‘network link’ within Google earth with the url https://cloudrf.com/krs3 . Once opened, you will be prompted for a password. After that you will receive several layers providing different functionality or reference data. To perform a new calculation, click the orange icon in the middle of the map screen to open up a pop-up form within Google earth or an external web browser, then enter system and environmental parameters and finally click a button to initiate calculation of the result. The variables are all passed to a server running propagation software supported by terrain, antenna and clutter datasets. The server produces the overlays and then displays a KMZ file link which needs to be clicked to be viewed. The KMZ can also be opened in compatible GIS applications which properly support the KML 2.2 standard.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
CloudRF.com
Page 1 of 18
Copyright 2013 Farrant Consulting Ltd
Keyhole Radio user guide
Documentation Version 5.0
1 Introduction 1.1 System overview 1.2 Concept of operations 1.3 Accounts and login 2 Operation 2.1 User interface 2.2 Calculate options 2.3 Transmitter options 2.4 Antenna options 2.5 Receiver options 2.6 Environment options 2.7 Layer options 2.8 Path Profile Analysis
3 Data 3.1 Terrain data 3.2 Radio templates 3.3 Antenna templates 3.4 Ground clutter 3.5 User archive 4 Miscellaneous 4.1 Linux compatibility 4.2 Repeater chaining 4.3 Exporting results 4.4 Performance tips
5 Examples 5.1 Push to talk VHF radio 5.2 Mobile phone mast 6 Technical support 6.1 Trouble shooting 6.2 Frequently asked questions [email protected]
1 Introduction 1.1 System overview
Keyhole Radio is a unique and powerful radio planning plugin for Google earth™. The
software is server based meaning end users only need to open a Keyhole Markup Language (KML) overlay in Google earth to use it. It's ideal for organisations already using Google earth as it can be deployed effortlessly to users as a URL and the KML output is visualised along with existing data layers as a common operating picture (COP). The system’s terrain data, radio templates, antenna patterns and ground clutter are all managed server side so the client only needs Google earth and a network connection. A user account is required to use the service. 1.2 Concept of operations The software acts as a plugin to Google earth. To open it, either launch the KML file from cloudrf.com or add a ‘network link’ within Google earth with the url https://cloudrf.com/krs3. Once opened, you will be prompted for a password. After that you will receive several layers providing different functionality or reference data. To perform a new calculation, click the orange icon in the middle of the map screen to open up a pop-up form within Google earth or an external web browser, then enter system and environmental parameters and finally click a button to initiate calculation of the result. The variables are all passed to a server running propagation software supported by terrain, antenna and clutter datasets. The server produces the overlays and then displays a KMZ file link which needs to be clicked to be viewed. The KMZ can also be opened in compatible GIS applications which properly support the KML 2.2 standard.
1.3 Accounts and login Authentication is required to access the software. This ensures only trusted people have access to the service and ensures a higher quality of service for all. It also allows for simple monitoring and segregation of data on the server. When the layer is opened for the first time, an authentication dialogue will appear prompting the user to enter a username and password. This account must exist on the server and be defined by a system administrator within the user table. If the link is opened with http:// then a non-secure warning will be appended to the dialogue, otherwise for https:// links, the warning is suppressed and the login is protected with SSL encryption. Note: Google earth Linux does not support SSL. See Miscellaneous.
2 Operation 2.1 User Interface
Once logged in, the layer will render several different features; a banner in the top left corner showing session information, a layer of green rectangles over the earth showing terrain coverage (each tile is 1x1 degree) available and an orange button in the centre of the screen. The orange button appears after the view has changed and settled and will only appear once the view has focused and zoomed into a country as opposed to a continent. To perform a calculation, click the orange button.
CloudRF.com
Page 3 of 18
Copyright 2013 Farrant Consulting Ltd
The pop-up calculation form contains a tabbed input form with a wide range of options of varying importance. New users will be able to generate approximate calculations using just the first two tabs (Frequency/Power/Height) but for an accurate prediction, users should be adjusting settings on all six tabs to define the antenna parameters, environment variables and receiver type and threshold. The form can also be opened outside of Google earth using the ‘open in web browser’ hyperlink. This can be beneficial to users with multiple monitors who can keep their Google earth view clear of visual obstructions. The hyperlink opened is unique to the logged in user and expires after a time. Bookmarking or sharing the link is not advised. Initially, the location used will be the centre of the screen. This can be adjusted within the second tab. 2.2 Calculate options The first tab contains the most basic values and the calculate button which is used to start the calculation.
Template The template box will display a list of saved radio templates after 3 characters eg. VHF have been entered into it. The templates can be selected with a click and will automatically populate the relevant fields within the form with saved values. To add a template click the ‘Add’ hyperlink to the right. For more on templates, see the data section.
CloudRF.com
Page 4 of 18
Copyright 2013 Farrant Consulting Ltd
Frequency Enter the channel frequency of the radio system in megahertz (MHz). Acceptable values are 20 to 20,000MHz. ERP Enter the total effective radiated power (ERP) of the radio system in Watts. Novice users should just enter their radio’s wattage as per its specification eg. 5W. Advanced users can enter transmitter power (W) and antenna gain (dBi) to automatically calculate the ERP on the antenna tab (#3). Maximum value is 2MW (2,000,000W). Radius Enter the maximum distance in either kilometres or miles for the coverage plot. This should be no more than the range of the most distant station. To change distance units, click metres or feet within the second transmitter tab. The maximum value possible is determined by the server and is typically 200km. Calculate The calculate action button executes the calculation. Whilst running, it will be greyed out and cannot be clicked until the calculation completes. In the event of a calculation result failing to display (>60 seconds delay) the form must be reloaded to reset the button. Description The filename description field allows for up to 25 characters to describe a calculation, for example ‘Fire station’. This name is visible in both the archive and the KML layer within Google earth. If left as ‘Description’ it will result in the default filename of date, time and frequency. 2.3 Transmitter options The second tab contains geographic information including the emitter location, height above ground level and distance units. Antenna location Enter the location of the emitter in either Decimal degrees, Degrees-minutes-seconds or NATO Military Grid Reference System (MGRS). Entering a value within one row will automatically result in a conversion to the others. By default this is the centre of the screen. Antenna height Enter the height of the antenna above the ground. The metres or feet toggle next to it will also change distance units for all other measurements within the form including radius and receiver height(s).
CloudRF.com
Page 5 of 18
Copyright 2013 Farrant Consulting Ltd
2.4 Antenna options
The third tab contains advanced settings related to antenna radiation patterns. It allows a choice between pre-made 3D templates or a custom 3D pattern based upon user supplied values. For both methods, there will be two adjacent images shown which depict the horizontal (bird’s eye view) and vertical (side on) radiation patterns. Most users should find a template to suit their needs and will only need to rotate the antenna by defining the ‘direction’ (degrees from north) field. Templates Templates are stored in a database in .ant v3 format (360 rows of horizontal values, 360 rows of vertical values) compatible with other popular planning applications. A template is selected by choosing it from the drop-down menu. New templates can be uploaded in .ant or .pat formats via the ‘Add’ link. To compare all patterns in detail click the ‘Add’ link to open the antenna dashboard. All antenna patterns are referenced to 0dB (100% radiation) so a round green pattern with 0dB all round would be radiating at 100% power in all directions. Custom The custom option allows users to create a pattern on the fly by defining key fields (direction, downtilt, horizontal beamwidth, vertical beamwidth, gain, front-to-back ratio). As values are changed within these fields, the pattern will automatically update. Tip: Novice push-to-talk (PTT) users should select a ‘Dipole.ant’ (omni-directional monopole) pattern. Polarisation Antenna polarisation/polarization describes the physical orientation of the antenna. Most broadcast systems are vertical, whilst some data systems are horizontal to reduce (vertical)
interference. Default is vertical.
CloudRF.com
Page 6 of 18
Copyright 2013 Farrant Consulting Ltd
Direction The horizontal angle (azimuth) the antenna is pointing referenced to grid north. Values of 0-360 are allowed. Not to be confused with beamwidth. Down tilt The downtilt is the vertical angle the antenna is pointing relative to the horizon. Acceptable values are -10 to (+)90 degrees where angles above the horizon (pointing up) are negative and angles toward the earth (pointing down) are positive. If an antenna was parallel to the ground it would be 0 degrees. For example, a directional antenna on top of a tall hill pointing down into a valley would have a positive downtilt. A similar antenna down in the valley would have a negative downtilt as it would be looking up the hill. Default is zero (no tilt). Horizontal Beamwidth This describes the angle in degrees between the two half power (-3dB) points of a directional antenna in the horizontal plane. For example, a directional ‘one third’ panel on a GSM cell tower would have a beamwidth of 120 degrees. This setting can only be applied in ‘custom’ pattern mode. Vertical Beamwidth This describes the angle in degrees between the two half power (-3dB) points of a directional antenna in the vertical plane. For example, the previously mentioned 120 degree (horizontal beamwidth) GSM panel may have a smaller vertical beamwidth of only 30 or 45 degrees, otherwise it will be wasting energy radiating the sky above it. This setting can only be applied in ‘custom’ pattern mode. RF Input Power Transmission RF power in watts is the amount of power supplied by a radio and is normally smaller than the total effective radiated power (ERP) of a directional antenna system. It is used along with gain to calculate the total effective radiated power (ERP) of the system. Max Gain The directional gain of an antenna measured in dBi. This is a numerical value between 0 and 50. For 1:1 gain (no additional power) then a default figure of 2.15dBi should be used. A high gain antenna would be greater than 10dBi. Adjusting this will result in an automatic adjustment to the ERP value on both the antenna tab and the initial ‘calculate’ tab. Front to back ratio This ratio measured in dB relates to the difference in power between the front and the back of the antenna. A value of 2 would mean the antenna was almost as powerful to the rear as to the front whereas 40 would mean nearly no power was radiated to the rear. This is automatically set to twice the gain so a 7.5dBi antenna would have a 15dB FBR. Maximum is 70dB. ERP Effective Radiated Power (ERP) is the total RF output of a system and is automatically calculated using the following formula:
ERP = Transmitter Power * Feedline Loss * Antenna Gain This value, once changed is automatically set on the first ‘Calculate’ tab as well.
CloudRF.com
Page 7 of 18
Copyright 2013 Farrant Consulting Ltd
2.5 Receiver options The fourth tab contains advanced settings relating to the receiver(s) settings. An incorrect value here can result in significantly unrealistic results. Receiver height The height above ground level of the receiver(s). Distance units are defined on tab two. For a man holding a handheld radio or phone, set this to 2 metres. Units of measurement The output units determine how to represent the propagation. Selecting dB (decibels) will ignore the Power output (ERP) and depict the path loss caused by the terrain. Handy for identifying high loss blackspots in the terrain. Selecting dBm (decibel milliwatt) will factor in all variables and depict the radio coverage. This should be used as standard or when uncertain. Selecting dBuV/m (Decibel microvolts per metre) will show the electrical field strength present in the ground and is best used for scientific surveys relating to RF radiation levels. Receiver sensitivity The coloured key and selected value changes according to the measurement units selected above it. For all three units, a strong signal is to the left (yellow) and a weak signal is to the right (purple). An optimistic result can be achieved by setting the slider to -110dBm whereas -50dBm would provide a more cynical result and can provide extra realism in suburban environments where ground clutter is not available to simulate concrete screening and absorption. If you do not know your receiver sensitivity then -90dBm is a good average. 2.6 Environment options The fifth tab lists advanced options for defining man made obstacles (clutter) and ground conductivity. The features here will help advanced users achieve the most realistic coverage plot for an area, especially in suburban or extreme climatic environments. Random clutter Buildings can be rapidly simulated using the slider, up to 50 metres (150 ft) high. This will increase the ground height all around the site to simulate a layer of buildings above ground level. Database clutter A much more precise simulation of man-made buildings can be done by uploading an overlay of
CloudRF.com
Page 8 of 18
Copyright 2013 Farrant Consulting Ltd
points to mark building locations via the ‘Upload KML’ hyperlink. This overlay should be a KML containing either placemarks, polygon corners, line points with heights in metres defined in the point properties. A quick way to define a row of two storey buildings is to use the Google earth line feature and click once per building then set the line’s height to 6 metres in Google earth. Save off the line to a .kml file and upload it. A single click will create a 90mx90m building. To define a larger building, click each corner. Ground conductivity The conductivity slider allows you to compensate for different environments using a dielectric value which describes electrical conductivity through the ground. A city has very poor conductivity whilst a wet marsh has very high conductivity. This is relevant for radio systems which operate at ground level such as hand held radio. Climate The climate slider allows you to compensate for different environments using a climate code which affects propagation through space. This is relevant for radio systems which operate high up such as over the horizon microwave links. 2.7 Layer options The sixth tab’s options do not affect actual propagation results with the slight exception of resolution which changes the granularity of the output. They determine formatting of results after calculation. Resolution This option relates to the pixels per degree of output files. A high resolution employs 1200 pixels for each degree on the earth which at the equator is about 90 metres. This figure reduces towards northern latitudes. A medium resolution is 600 pixels so twice the distance and low is half again (300 pixels). Calculation time is affected significantly by the resolution. Transparency The transparency/opacity slider applies to the Google earth ground overlay. This value can also be manipulated post calculation manually within the layer’s properties. Colour schema The colour of the output file can be set here. For single colours like ‘Reds’ a range of dark and light reds will be used to denote strong and weak signals. A key is supplied with each layer for reference. Greyscale terrain background Enabling this will draw the terrain background for the overlay which can be helpful when sharing the layer with other users or viewing it on systems with limited mapping. This feature greatly increases resultant filesize.
CloudRF.com
Page 9 of 18
Copyright 2013 Farrant Consulting Ltd
2.8 Path Profile Analysis
The Path Profile Analysis (PPA) feature allows a point to point (P2P) study from the transmitter (Tx) which generates a 2D profile graph and text report highlighting obstructions. To use the PPA feature select a radio coverage layer and then focus the viewer on to a point within the coverage area where you would like to have a receiver (Rx). Expand the layer’s components within the left hand layer tree to reveal the ‘Path Profile Analysis’ network link, select it and press Ctrl-R to run a PPA. (Alternatively, right click the layer then select ‘refresh’) After a brief delay, a signal strength icon will appear on the map centred on the centre of view with a value representing the signal strength. Click this icon to view the report and 2D graph with Fresnel zones.
3 Data
3.1 Terrain data
The system uses public Shuttle Radar Topography Mission (SRTM) version 2 data sourced
from the NASA 2000 mission which is a modified dataset improved by the National
Geospatial Intelligence Agency (NGIA). The modifications removed erroneous spikes
although the data still contains a small number of voids in mountainous terrain caused by
radar shadow.
The public data is accurate to 90 metres / 270 feet and equates to Digital Terrain Data
(DTED) level 1 for Government users. The NASA data extends to 60 degrees latitude in both
CloudRF.com
Page 10 of 18
Copyright 2013 Farrant Consulting Ltd
poles with extra polar data courtesy of Cartographer Jonathan De Ferranti BA
(http://viewfinderpanoramas.org) who has created the data.
The data only depicts the earth’s surface and does not generally include man-made
structures however large elongated concrete features (present in the year 2000) have been
included. Tall ‘sky scrapers’ were smoothed out of the data as part of the version 2 data
scrub.
The picture below depicts the presence of man-made obstacles within the SRTM data as
radio waves are visibly affected by concrete pontoons in Marseille harbour.
Man made obstacles created after the year 2000 are not factored in as this picture shows.
The Dubai Palm Jumeirah development was started in 2001, much to the dismay of NASA