1. - - - - - - - - - - - NSARC HF Operators18 Oct 2014 Rev 1 HF OPERATORS HIGH FREQUENCY TERRAIN ASSESSMENT HFTA and MicroDEM by John White VA7JW va7jw@shaw.ca

2. - - - - - - - - - - - NSARC HF Operators28 Oct 2014 Rev 1 What is HFTA ?  Antenna modeling software (i.e. EZNEC) typically models over FLAT TERRAIN  The physical features of the land at your QTH will alter the flat terrain vertical radiation pattern model  HFTA software models the vertical radiation pattern of your antenna based on your actual terrain ACTUAL TERRAIN ALL DIRECTIONS = 360 degrees

3. - - - - - - - - - - - NSARC HF Operators38 Oct 2014 Rev 1 Where to Get HFTA?  HFTA is ARRL proprietary software supplied on a CD which is included with every ARRL antenna handbook since 2003  It cannot be purchased from ARRL as a stand-alone package nor be downloaded for the web  HFTA was developed by Dean Straw N6VB while employed at ARRL as Senior Technical Editor for many publications  Copy the HFTA files to your PC from the CD  Runs under Windows XP and Win 7

4. - - - - - - - - - - - NSARC HF Operators48 Oct 2014 Rev 1 HFTA Features  HFTA allows experimentation with different antennas at different heights to characterize a given installation, or optimize and design a new installation, at a given location / terrain  Computes horizontally polarized radiation, sorry - no verticals  Dipoles and yagi’s from 2 elements to 6 elements  Heights > 1 foot above ground, at antenna site  Bands from 160 through 10 meters  Shows only low angle radiation < 34 degrees (why later..)

5. - - - - - - - - - - - NSARC HF Operators58 Oct 2014 Rev 1 Vertical Radiation Plots  Example: Vertical elevation plot – dipole - 1 wavelength high over flat terrain  Lobes show angles of maximum gain and minimum gain, (peaks and nulls)  Loss effect of real ground is also noted

6. - - - - - - - - - - - NSARC HF Operators68 Oct 2014 Rev 1 Effect of Terrain  Recombination of the Direct wave and ground Reflected wave determines the angle at which max and min lobes appear  Higher the antenna, the lower becomes the first maximum lobe with more lobes developing with increased height  The angles of reflection are also determined by  the distance from the antenna to terrain variations  the angle of the terrain to the antenna – rising, falling, flat …  rising ground will increase low angle, falling will decrease low angle 15 degrees 10 degrees5 degrees

7. - - - - - - - - - - - NSARC HF Operators78 Oct 2014 Rev 1 How Lobes are Formed  Lobes occur due to the phase re-enforcement or cancellation of the direct wave from the antenna and the reflected wave from the ground  (Reflected wave undergoes a 180 deg phase shift since E field must = 0 at t he surface of a conductor, i.e the ground) Formation of a Max Lobe at 50 degFormation of a Null at 30 deg

8. - - - - - - - - - - - NSARC HF Operators88 Oct 2014 Rev 1 Where’s the Terrain Info?  HFTA does not contain terrain / topographical information  HFTA uses a digital topographical mapping application which renders topographical information into a file format suitable for use by HFTA  MicroDEM is the companion mapping software that provides HFTA with the required land profiles for mapping  More on MicroDEM later ….

9. - - - - - - - - - - - NSARC HF Operators98 Oct 2014 Rev 1 HFTA – What will it do?  Enter the Type and Height of your antenna above ground  Enter Frequency  Enter the geographical definition of your terrain from MicroDEM  HFTA will calculate the terrain profile every 5 degrees around your QTH out to 4400 m / 14,500 feet  HFTA will plot the vertical angle of radiation of the antenna,  can be compared to flat ground performance  can be compared to the arrival of low angle DX signals

10. - - - - - - - - - - - NSARC HF Operators108 Oct 2014 Rev 1 Main HFTA Window  Enter Frequency  Terrain Files  as generated by MicroDEM are loaded here  Ant Type  select the antenna from a drop down menu  Height of Antenna – type in  There are 4 fields so that 4 models can be compared

11. - - - - - - - - - - - NSARC HF Operators118 Oct 2014 Rev 1 Completed Window  MicroDEM has generated a profile at a 60 deg AZ from my QTH. 3 element yagi at 60 ft, all entered  Loaded the Flat File that plots patterns of flat terrain  Checked both lines 1 and 4 to plot pattern of same graph

12. - - - - - - - - - - - NSARC HF Operators128 Oct 2014 Rev 1 Terrain Profile Plot  Hit the Button Height of Antenna above ground Ground (Terrain) Profile at 60 degrees Azimuth Burrard Inlet – Sea LevelBurke Mtn Ridge

13. - - - - - - - - - - - NSARC HF Operators138 Oct 2014 Rev 1 Vertical Radiation Plots  Hit the Button  Typical Gain over Flat about 4 to 6 dB out to 20 deg. The Negative Profile advantage  No advantage 14 to 18 degrees  Sharp nulls at 8 & 23 deg  One would experiment with various heights to find optimum performance Antenna Pattern Flat Terrain Pattern

14. - - - - - - - - - - - NSARC HF Operators148 Oct 2014 Rev 1 DX Low Angle Skip  Many DX signals arrive at low angles due to long skips  Long skip typically arrives at < 34 degrees (ARRL Antenna Handbook 21 st edition, pages 3-21 ff)  Antenna performance for low angle / long skip of particular interest to DX operators  HFTA allows for examination of low angle arrivals with respect to the vertical elevation antenna plot  Enter desired angle coverage in HFTA window.

15. - - - - - - - - - - - NSARC HF Operators158 Oct 2014 Rev 1 DX Profile Files  HFTA is supplied with files (.PRN) that provide a statistical angle of arrival of DX signals as a percentage of time that can be plotted along with the vertical radiation pattern  Select your call zone i.e. VE7 from the.PRN file listing  Areas are Africa (AF), South Asia (AS), Europe (EU), Far East (JA), South Pacific (OC), South America (SA), and the US  Select the DX “area” from the list of VE7 files by clicking in the Elevation field of HFTA  The PRN elevation file is entered in to the HFTA main window

16. - - - - - - - - - - - NSARC HF Operators168 Oct 2014 Rev 1 The Complete Plot  Introduce the EU file for DX angle of arrival  Bar graph representation  Most often, signals arrive between 3 and 6 degrees  Antenna pattern happens to peak in this area – that’s good  Try other bands, directions  That’s it! except for the mapping ….

17. - - - - - - - - - - - NSARC HF Operators178 Oct 2014 Rev 1 Maps and MicroDEM  MicroDEM software loads and displays digital topographical maps  Digital topographical map is called a DEM = Digital Elevation Module (Digital Elevation Map makes more sense)  DEM’s are 3 dimensional topographical providing latitude, longitude and elevation  Canada and US DEM’s are available on the web and are free  MicroDEM processes these maps & provides HFTA with terrain files that allows HFTA to plot the profiles and calculate the vertical radiation patterns

18. - - - - - - - - - - - NSARC HF Operators188 Oct 2014 Rev 1 Where to Get MicroDEM?  MicroDEM is downloadable from the web, free  Do NOT download the MicroDEM version from the ARRL CD. It is out of date  Developed by Professor Peter Guth of the US Naval Academy http://www.usna.edu/Users/oceano/pguth/website/microdem/microdem.htm  The latest MicroDEM version is now 64bit  Runs under Windows XP and Win 7

19. - - - - - - - - - - - NSARC HF Operators198 Oct 2014 Rev 1 About MicroDEM  MicroDEM is a powerful and complex application  Do not “experiment” with it as setup is critical  Recommend downloading “Beginners Guide to HFTA” for setup directions and settings to get started http://www.nsarc.ca/tech_archive/Articles/hfta.pdf  Also download “Operating Instructions for HFTA Ver 1.04” by Dean Straw, dated 22 Feb 2013, http://www.arrl.org  or go to the ARRL website, search for HFTA, click on HFTA …

20. - - - - - - - - - - - NSARC HF Operators208 Oct 2014 Rev 1 Canadian DEM’s  Access DEMS at http://www.geobase.ca http://www.geobase.ca  Geobase > data > digital elevation data  Whole Canada map  Select General Region  i.e. South West Canada, Region 92  Click on 92 to expand  Region 92 is subdivided  Select Vancouver is 092G  Click to expand again

21. - - - - - - - - - - - NSARC HF Operators218 Oct 2014 Rev 1 Expanded DEM  DEM now shows districts within 092G  Click on the NAME closest to QTH  This case Port Coquitlam (PoCo)  Data field below map shows selected DEM file(s) for download  092G07 is the DEM file for PoCo  This is downloaded to a directory set up by HFTA

22. - - - - - - - - - - - NSARC HF Operators228 Oct 2014 Rev 1 Sub-DEM Structure (Canadian only)  Sub sections within 092G are identified by suffixes 01 thru 08 with attached names as shown. Each sub section has an East and West map i.e. demw – DEM west and deme = DEM east

23. - - - - - - - - - - - NSARC HF Operators238 Oct 2014 Rev 1 MicroDEM Appearance  Main window  This is a map of the lower mainland, a composite of 8 DEM’s  North shore Mtns  Harbour  Vancouver  New Westminster  Surrey  Richmond, Delta, Ladner

24. - - - - - - - - - - - NSARC HF Operators248 Oct 2014 Rev 1 Opening the DEM’s  Refer to Beginners Guide for unzipping and saving the file  When DEM file has been selected, open in MicroDEM  First time may take a moment to interpret  Display is set to represent elevation by color. Blue ~ sea level, red ~ 2000m  Resolution looks miserable but it is not  Magnification can show great detail  MicroDEM will stitch together maps to make larger maps i.e. lower main land VA7JW QTH

25. - - - - - - - - - - - NSARC HF Operators258 Oct 2014 Rev 1 Where Am I ?  You have to know where you are located, accurately  Use Google Earth (suggest version 7.1.1.1888 or later)  Enter your street address in the SEARCH field  Magnify and find your house  Zoom in and place cursor on top of your antenna / tower  Lower right, read off your Latitude. Longitude and Elevation i.e. 49 degrees 16 minutes 59.73 seconds North etc., EXACTLY (why?)

26. - - - - - - - - - - - NSARC HF Operators268 Oct 2014 Rev 1 Position Accuracy  Profile plots and antenna pattern accuracy are based on position of antenna / tower on the map. Get within 10 ft.  Distances between Latitudes are constant North to South  Distance between Longitudes varies with Latitude North and South of equator > becomes zero at Poles  Table shows uncertainty of location at equator; E-W error becomes less at higher latitudes.

27. - - - - - - - - - - - NSARC HF Operators278 Oct 2014 Rev 1 Find QTH on the Map  Write down the Google Earth coordinates  Open up your MicroDEM QTH map  Mouse over estimated QTH  Watch bottom of MicroDEM window for Lat, Long and Elev readings  Move mouse until Lat Long read ~ same as Google Earth Lat & Long  That’s your QTH (VA7JW)

28. - - - - - - - - - - - NSARC HF Operators288 Oct 2014 Rev 1 Enter QTH in MicroDEM  Double Click on your QTH  Window appears with Lat and Long of the mouse on map  This does not have to be precisely set on the map  Now enter the exact Lat and Long as per Google Earth in the fields  MicroDEM now knows exactly where your antenna is

29. - - - - - - - - - - - NSARC HF Operators298 Oct 2014 Rev 1 FAN Generation  MicroDEM, will generate a land profile, radially from the QTH, every 5 degrees, over 360 degrees, out to 4400 meters  This “suite” of files is referred to as a FAN  Each 5 degree profile is saved as a.PRO file  There is one file for each 5 degree increment (71 in total)  This is the field that will populate the HFTA window under the Terrain Files field ( MicroDEM saves these files automatically as degrees (i.e. VA7JW-60.00.PRO) Suggest renaming with date & time stamp i.e. VA7JW-21jun13-1708-60.00.PRO)

30. - - - - - - - - - - - NSARC HF Operators308 Oct 2014 Rev 1 HFTA is READY  You can now run HFTA to do your site analysis  Run profiles  Run antenna patterns  There are other very important, useful features in MicroDEM  MicroDEM will plot,  The Blocking Horizon  Topology coverage map  Lines of Sight, useful for VHF/ UHF

31. - - - - - - - - - - - NSARC HF Operators318 Oct 2014 Rev 1 The Blocking Horizon  The horizon limits the ultimate angle for blockage of signal, both on transmit and receive  MicroDEM will graph the blocking horizon  Line of Sight – your QTH to the horizon in terms of vertical angle as well as distance to the blockage vs. azimuth  Horizon Blocking Plots  Elevation plot to blocking horizon, over 360 degrees  Distance plot to the blocking horizon, over 360 degrees  Topographical MAP showing areas where blockage occurs

32. - - - - - - - - - - - NSARC HF Operators328 Oct 2014 Rev 1 VE7NSR Example  A Topographical map showing blocking horizon  The Vertical elevation plot to the horizon, in degrees  can also run distance to blocking horizon  Reveals problematic areas as well as good areas, by Azimuth  Plot profiles in directions of interest as well as worst & best  Take into account antenna beam width with respect to coverage

33. - - - - - - - - - - - NSARC HF Operators338 Oct 2014 Rev 1 VE7NSR Topology  Blocking Horizon from NSEMO out to ~ 20 km

34. - - - - - - - - - - - NSARC HF Operators348 Oct 2014 Rev 1 VE7NSR Blocking Horizon Grouse Seymour Cypress Lions Buraby Mtn VancouverStraits

35. - - - - - - - - - - - NSARC HF Operators358 Oct 2014 Rev 1 VE7NSR, the HFTA Plots  PRO files generated  Freq 14.2 MHz  PRO file at 120 0, 3 ele yagi at 70ft entered  Flat Terrain file  DX Rx angles.PRN files for South America

36. - - - - - - - - - - - NSARC HF Operators368 Oct 2014 Rev 1 Typical 2 Degree Horizon  North Van platform at 120 degrees  Land profile drops, looking up Burrard inlet towards Bby Mtn  Actual is not as good as Flat

37. - - - - - - - - - - - NSARC HF Operators378 Oct 2014 Rev 1 Worst Case, 9 0 Horizon  Grouse blockage  Ant pattern is impaired for Low angle DX  Flat Terrain  DX Arrival Angle

38. - - - - - - - - - - - NSARC HF Operators388 Oct 2014 Rev 1 Best Case, 0 0 Horizon  Negative Horizon, ground slopes away at 250 0  Ant pattern excellent  No blockage of low angle sig arrival. Good for DX

39. - - - - - - - - - - - NSARC HF Operators398 Oct 2014 Rev 1 LOS – Bowen Repeater  LOS is Line Of Sight  VHF/ UHF path  Green is visible  Red is obscured Mt Gardner NSEMO

40. - - - - - - - - - - - NSARC HF Operators408 Oct 2014 Rev 1 LOS – Seymour Repeater  VHF – UHF Path (actual repeater site – tower uncertain)  and for something really cool > NSEMO

41. - - - - - - - - - - - NSARC HF Operators418 Oct 2014 Rev 1 Panoramic View - NSEMO  MicroDEM generates a panorama view that can be scrolled through 360 degrees Grouse Lions Seymour Eagle

42. - - - - - - - - - - - NSARC HF Operators428 Oct 2014 Rev 1 DONE  Once the PRO(files) are generated, HFTA is ready to compute  Characterize your location  all antennas (horizontally polarized only)  all heights  all bands  all directions  Vancouver has a complex horizon - good and no so good for DX  plot your horizon as shown slide 34  know which parts of the world are at what azimuth, slide 34  blockages mean low angle will be impaired but under most openings, higher angle is common and DX will be worked

43. - - - - - - - - - - - NSARC HF Operators438 Oct 2014 Rev 1 Summary  HFTA and MicroDEM will provide a characterization of your antenna vertical radiation patterns as altered by local terrain at your QTH  HFTA software is easy to use  MicoDEM mapping software takes effort to setup  To make this task EASIER download “Beginners Guide to HFTA and Microdem” at: http://www.nsarc.ca/tech_archive/Articles/hfta.pdf  Provides step x step instructions