RF Explorer (Beta) It really is a simple process to collect signal data about a known transmitter or RF Source. However, you will need some items and some knowledge to make the process painless and actually kind of fun. I have listed everything here as a checklist towards beginning the process. Please read this entire section BEFORE you begin using the software. This will aquaint you with the necessary knowledge to get you up and running with the RF Explorer Software and reduce any frustration factor you may have with new software and connecting additional hardware to the computer. Things Need BEFORE you get started: 1. Working GPS Device capable of sending NMEA 0183 data to a serial port on the computer you are using to map. 2. A working second serial port to connect your GPS device. 3. A second serial port cable to connect the GPS Device to your computer 4. KE7ATE PCR-1000 Signal Capture and Analysis Software (Loaded and setup) 5. ICOM IC-PCR1000 Communication Receiver 6. Power Inverter to connect your laptop to your vehicle 7. Cigarette lighter power adapter for the IC-PCR1000 to power it from the vehicle 8. Appropriate antenna for the signal you will be capturing 9. A comfortable logging position in your vehicle or place to control your laptop as you drive. 10. Any other cable you need to connect your system together 11. Make sure you have enough real estate on your computer screen to display the map view window. (At 1280x1024, my Dell 8100 has enough room to comfortably display the map view window. Yes, I know this computer is old, but I have my reasons for using it for this software and this is just one of the many.) Safety One of the most important parts of making this a successful and interesting process, is to ensure you have a safe and comfortable operating position within the vehicle. There is really no reason to change any settings in the software once you are driving and collecting data. The software was designed to reduce any user interaction while driving. I did this for the safety of the driver, any passengers, nearby pedestrians and other vehicles on the road. If in case you do need to make an adjustment and you are drivng and collecting data without any assistance, I highly recommend and strongly suggest that the driver/operator find a safe place off the road or terrain to manipulate the software, since it involves a laptop and/or detail oriented adjustments. Trying to manipulate any changes or control the receiver while driving can endanger you, nearby pedestrians and other drivers on the road. Please take any precautions to be safe while driving and collecting data with this software. I am not responsible for any situations that may be unsafe or become unsafe while using this software. You as the driver/operator are responsible for what goes on inside your vehicle. Origins of this Software One of my goals with this software is to make it as simple as possible to use, yet as comprehensively complete as necessary. I developed this software because I wanted to get an idea of the coverage patterns of a few local transmitters in my area. Knowing that there was very little out there that did what I wanted to do, I set out on the task of making my own software to perform this exact function. Several years ago (back in 1999) I found a web site of a gentleman who did this same thing, but the software only worked with a specific setup, special hardware and ran under MS-DOS. Also, his software, though it was very cool, didn't display the data in real time as it was being collected. So, you had no way to verify everything was working as expected while collecting the needed data. You literally could go the whole time and not know for sure if what you were collecting was going to be usuable after processing the data. So, it was time to get to work on a better way. Over a year ago, as I was working on my software, I opened up a trade magazine a saw an article on almost the same exact thing I had developed. The similarities were suprising, almost scarey. Although, the needed equipment and software was much more expensive than I would dream of paying just to map a signal or emission pattern. My development demanded a simple yet effective method to aquire or capture similar information. Since, I was already aquiring this data through the interface, it was a natural progression to create this software. Although, my software is not what I would consider commercial quality, it has many features and can do a variety of things that could make it competitive with some commercial software packages. My system allows the measurement of only one transmitter or RF source at one time and it is significantly easier to use. Connecting Your GPS to the Computer This is essential to getting the RF Explorer software working properly and graphing real time signal information over a given terrian. First, you will need a GPS device that can transmit NMEA data to the serial port of a computer. If you are new to using GPS or lack some knowledge as to how it works. It is a good idea to do alittle extracurricular reading online about it and how to use GPS devices. The NMEA data set includes information about your position, elevation and current UTC time that can assist you in knowing where you are in 3D space. I use the Latitude and Longitude data from the GPS device and corrolate it with the signal data to create a 2D map of the received signal at your present position. This is useful when you measure the output signal of a known transmitter or RF source to create a map of the resulting RF emissions. Your GPS device may require a special cable to connect to a secondary serial port on your computer. If you computer doesn't have a secondary serial port, you can add one using a USB to serial port Bridge cable. I don not recommend using a cheap one available from some internet aution sites. I have tried them and they do not work. I like to use cables that utilize the Prolific drivers and also cables listed on the Prolific driver web site. I have found that these work well and are uaually trouble free. I personally use an older cable that I found several years ago made by ioconnect. I have three of these and each one has worked flawlessly with the Macintosh computer and the latest Windows Operating system Windows Vista). Once you have a working secondary serial port, you will want to note its COM port number, because you will need to set this value in the Configuration and Setup dialog box of my software in order to make the connection to the RF Explorer software. Also, you will need to know what data rate your GPS device is sending data. Most send at 4800 baud, but I have seen a few that also send at 9600 baud. You will need to set this value in the Configuration and Setup dialog box of my software in order to make the connection function properly in the RF EXplorer software. Where are the Maps? You will need to make them for your own Use. It is simply impossible for me to provide maps of the entire planet earth when I only need a small chunk for my own use. It would be impractical for me to provide this data, but better if I provide a way for you to make your own maps from other sources. This is what I have done and at the same time, it has made it possible for you to use a variety of map sources in the RF Explorer software. For more information see the text under step 2 of the next section. A Typical Mapping Senario Setup 1. Tune your receiver to the frequency being used by the known transmitter or RF Source. Make any adjustments necessary to receive the signal under the conditions you have specified. I say this because you may have some special conditions your are investigating or you may not, depending upon your situation. I leave this up to you to decide. I know I have had to attenuate some signals to get a reduced mapping of the known transmitter or RF source. The attenuation can be calculated back into the values later if you are going to do some further analysis outside the scope of this software. The software doesn't account for any attenuation, but I may add this in a later version. Why use attenuation? Well, you may be trying to simulate conditions for a specific operator that uses a specific receiver or transceiver. Law enforcement agencies may find it useful to know what kind of coverage a vehicle mounted transeciver may have in relation to the dispatcher transmitter location. You are then putting your test receiver into a situation that must imitate the reception conditions of the communications system in question. Wow, simulation...this is really nerdy stuff. Extra measures may need to be taken in order to simulate the equipment under scrutiny. 2. Load the map of the area you will be covering. This may be any screenshot of the area you will be surveying that surrounds the known transmitter or RF source. I like to use aerial photos or maps from the Internet. Since they are easy to obtain and if you are using Google Earth, you can get a rough idea of what the bounding latitudes and longitude for the selected area are by noting them after you take a screenshot of the area you have chosen to survey. I simply take a screenshot using the print screen button on the keyboard and develop the correct size of map using Microsoft Paint (cut and Paste to and from the clipboard). The 'correct size' should be 800 pixels wide by 584 pixels in height, showing the area you will be surveying. Do not enlarge or reduce the screenshot once it has been taken, because the related bounding latitude and longitude corrdinates will be out of proportion and your real-time mapping will be very noticeably incorrect. Using the tools Microsoft has given us with the Windows XP OS makes this process simple to get you what you need to begin your RF survey. Another reason I like aerial photos is that they contain alot of terrian information not present in street maps, which can help understand how a signal may be propagated around nearby structures or natural barriers such as mountains. The beauty of using your own custom maps is that you can generate maps for almost any situation even after the data has been collected and saved to the hard drive. Looking at the map creation another way, you could theoritically, make the map later and do the signal mapping first and then add the map later. This way you could screenshot the plot to the clipboard and import it into more sophistocated image manipulation software, such as photoshop and combine the signal map and the aerial map using some transparancy. This will allow some of the aerial map to be visible through the signal map. 3. Load the known transmitter or RF source coordinates Latitude and Longitude (without the decimals) into the appropriate RF Source latitude and longitude boxes. Future versions may automate this process. This is designated by knowing the latitude and longitude of the transmitter or RF source. 4. Load the accompanying map coordinates, Latitude and Longitude (without the decimals), into the bounding coordinate boxes. Future versions may automate this process. These are the coordinates you noted when you processed the map image. Initialization 5. Activate or turn on your GPS device. If you are using an eTrex like I do, you MUST wait for it to find the satellites and tell you, "READY TO NAVIGATE" on the display before you press the GPS "On" button in the map window. It usually needs to lock on four satellites before I get a "READY TO NAVIGATE" message. If you don't wait and turn the GPS Device connection on before you are "READY TO NAVIGATE", the software will error out and crash. This is the nature of the serial port connection, but as long as you wait for the GPS unit to initialize and give you this message, you will be ok and ready to go. 6. You should see NMEA data filling the NMEA data view in the lower left hand part of the map window. This is good. Also, you will note a colored dot or line at your present location in the map display overlaying your chosen map. This is also good. The color depends upon your signal strength from the known transmitter or RF Source location. If you do not see these things, your GPS device is not sending NMEA strings to the computer. You must have NMEA data being processed before you can continue to the next step. Driving and Collecting the Signal Data 7. Once you have all of this set up and working, drive to the furthest point at which the signal strength of the known transmitter or RF source is at its weakest, but remaining within the area defined by the map view. As you drive, depending upon which type of graphing you have chosen, you may see radial lines from the known transmitter or RF source location to your driving path or simple a multicolored series of dots creating as a line indicating your drive path. 8. Find your start location. Press the 'Clear' button to clear the map view. This doesn't remove your map, just the mapping of the signal lines. 9. Press the Logging button to begin logging the current latitude, longitude, elevation, UTC time, and signal strength to a text file. This is optional, but a good idea if you want to plot the map for visualizing or use the collected data for further processing at a later point in time. 10. Travelling in one direction (do not back track), begin driving in a spiral driving path around the known transmitter or RF source until you find yourself back at the known transmitter or RF source location. (Spiraling inward towards the known transmitter or RF source location) This may involve predetermining a spiral-like path on existing roadways or terrian depending upon the driving conditions. The goal here is that you are trying to achieve a consistant spacing between the spiral paths. Part of being successful at aobtaining a consistant mapping of the signal emission pattern may be learning the roads or the terrian you will be doing your survey. This too will reduce any frustrations that may arise from going through this process. 11. As you drive your vehicle, your map view will reveal an emission pattern of the known transmitter or RF source. Although, you can devise your own senarios, these are the basic steps to achieving a map of a known transmitter or RF source. I have found the results to be very good and contains a lot of good information about the signal and its source. Also, I have found it useful to perform a test run of the system before I use it in a practical situation. This is important since, the arrangement of your vehicle may be different than my set up or weather conditions may not be optimal. There are any number of reasons that you should test before you go live. Just getting used to the software may be a good reason to try a few test runs before you do the real thing. Data Processing After you have collected your data, you have some options as to how you want to use the information. First, if you didn't chose to log the data during collection, the only real option you have of storing the information will be to copy a screenshot of the window on your computer to the clipboard and paste it into Microsoft Paint to save as a bimap file. The save view button is inactive because this is a feature I am trying to make work correctly. So, for now, the previously mention method of save a visual view of the map for later reference is the only method available for saving your work to the hard drive. No log information exists so this is only a visual record of what was recorded. In some situations this may be all you need. This is why I have a "On Top" and "Not on Top" button. The map window must always be "On Top" during mapping as to not obscure the visual data being collected. The window will automatically switch to being "On Top" when you are actively mapping and the GPS device is turned on. However, if you had the foresight to turn the logging feature on, you then may plot the data to the display at anytime in the future in a track or signal graph format. These are the same two mapping choices allowed when in real time data collection. So, the outcome is the same. Pressing one of the "Plot..." buttons displays a load file dialog box and allows the user to select a log file to display in the desired format to the map view. Clever tricks such as merging log files together, can work to your advantage. In case the software crashes (not the vehicle) and you need to restart the setup during data collection, you really don't have to start over. Just start where you had the problem and continue until you finish, reminding yourself that you will need to merge the files together after you have completed your survey. If you follow the steps listed above, everything should work out well. Merging files can also help in relating one suvery to another, bar any overlapping of graphs and the previous log file was not lost in the crash. The ability to use your own custom maps makes plotting your data interesting and more explanatory when you are looking for natural barriers or man made structures tha may be affecting the path or range of a received signal. Street maps don't show surronding terrian, but aerial and contour maps can reveal information about an area that was not easily visible in a street map. If you decide to use different maps, make sure they all use the same bounding coordinates, so the data may be related accurately between them. Using Other Software to Process the Data The only practical example of this is converting the Latitudes and Longitudes into Northing Eastings and the remaining data into elevation and description data so that it may be imported into AutoCAD and displayed and rotated in 3D. Neat stuff, but unless you can afford the cost of an AutoCAD license, you will need to find another method of interperlating the coordinates into another third-party software product. However, if you do have an AutoCad License and can do this kind of manipulation, the results can be wonderful. Viewing the signal emission pattern in 3D is very enlightening and can really give you a sense of how the signal propagates over the mapped terrian.