Weather Calc iPhone app performs Weather and Meteorology Calculations
Custom software is continuously reading A/D values from the SDR-14 (in real, not complex, mode). The A/D sample rate is approximately 66.67 MHz. Blocks of 262,144 readings are taken, and an FFT is performed. The result is an array of signal strength readings for the entire HF spectrum, 0 to 30 MHz.
For frequencies of interest, the software then computes the signal strength in dBm over a +/-3 kHz bandwidth around a center frequency. This is computed approximately twice per second, and these readings are averaged over one minute. They are then uploaded to the web server, where they are stored, and graphs are made on demand. These graphs show the last three days worth of readings. (Possibly less if I just started taking readings for that frequency)
The purpose of this is to log and chart the signal strengths of various stations, to observe actual propagation conditions at various times of the day.
There is a slightly more in depth description of the process on my blog
Do you have a suggestion for a frequency to monitor? Ideally, the frequency should have a station that is on 24 hours a day. If so, please pass it along: hfu @ hfunderground dot com
The Google Charts API is used to generate the graphs. I've tested this on several browsers, and it worked fine. Some users have reported probelms with specific browsers, such as IE, taking a while to generate the charts, so you may need to be patient.
Signal strength charts for the following frequencies are available:
24 kHz - US Navy NAA Station in Cutler, Maine
60 kHz - WWVB - Fort Collins, Colorado
254 kHz - No description available
289 kHz - DGPS Station located in Driver, VA
291 kHz - DGPS Station located in Hawk Run, PA
301 kHz - DGPS Station located in Annapolis, MD
303 kHz - DGPS Station located in Greensboro, NC
305 kHz - DGPS Station located in Dandridge, TN
307 kHz - DGPS Station located in Hagerstown, MD
309 kHz - DGPS Station located in Reedy Point, DE
530 kHz - No description available
1280 kHz - WHVR - Hanover, PA
1320 kHz - WGET - Gettysburg, PA
1710 kHz - Unallocated mediumwave band frequency
2396 kHz - CFH - Canadian Forces, Halifax, NS
2500 kHz - WWV - Fort Collins, Colorado
2574 kHz - CFH - Canadian Forces, Halifax, NS
3330 kHz - CHU - Barrhaven, Canada
3485 kHz - New York Radio and Gander Radio Aviation Weather
5000 kHz - WWV - Fort Collins, Colorado
5340 kHz - NAR Saddlebunch Keys, FL
5345 kHz - NPG Dixon, CA
6070 kHz - CFRX - Toronto, ON
6160 kHz - CKZN - St. John’s, NF
6270 kHz - Radio Cairo, Egypt
6385 kHz - CFH - Canadian Forces, Halifax, NS
6425 kHz - CFH - Canadian Forces, Halifax, NS
6489 kHz - NAR Saddlebunch Keys, FL
6604 kHz - New York Radio and Gander Radio Aviation Weather
6726 kHz - NAA Cutler, ME
6925 kHz - Used by pirate radio stations
6955 kHz - Used by pirate radio stations
7663 kHz - NAR Saddlebunch Keys, FL
7850 kHz - CHU - Barrhaven, Canada
9030 kHz - NAR Saddlebunch Keys, FL
9085 kHz - NPG Dixon, CA
9830 kHz - NAR Saddlebunch Keys, FL
10000 kHz - WWV - Fort Collins, Colorado
10051 kHz - New York Radio and Gander Radio Aviation Weather
10428 kHz - NPG Dixon, CA
10832 kHz - NDT Yukosuka, Kanagawa, Japan
10945 kHz - CFH - Canadian Forces, Halifax, NS
11687 kHz - NAA Cutler, ME
12015 kHz - NAR Saddlebunch Keys, FL
12120 kHz - NAR Saddlebunch Keys, FL
13270 kHz - New York Radio and Gander Radio Aviation Weather
13508 kHz - CFH - Canadian Forces, Halifax, NS
13870 kHz - NAR Saddlebunch Keys, FL
14670 kHz - CHU - Barrhaven, Canada
15000 kHz - WWV - Fort Collins, Colorado
15959 kHz - NAA Cutler, ME
16122 kHz - NAA Cutler, ME
16134 kHz - KVM70 Honolulu, HI
16200 kHz - Russian Navy
16268 kHz - NPG Dixon, CA
20000 kHz - WWV - Fort Collins, Colorado
20100 kHz - No description available
25555 kHz - No station, used to see noise levels
25910 kHz - WBAP Fort Worth, TX
25950 kHz - KOA Denver, CO
25990 kHz - KSCS Arlington, TX