HackRF Receiving HRPT Weather Satellite Images

On Twitter user @uhf_satcom has been using a HackRF software defined radio together with GNU Radio, a tracking L-Band antenna and this HRPT decoding software to receive and decode HRPT weather satellite images. He used GNU Radio to output to a .RAW16 file, which the HRPT decoding software was then able to use to produce an image.     HRPT is a picture transmission protocol which stands for High Resolution Picture Transmission. There are multiple satellites which broadcast weather images in this format including the NOAA, GOES, Metop-A and Feng Yun satellites. These satellites transmit HRPT at about 1.7 GHz. @uhf_satcom also tried to receive these images with the RTL-SDR, but was unsuccessful. But you can still receive the lower resolution APT weather satellite images using the RTL-SDR. Below are some examples of the images he was able to receive. hrpt_hackrf1_thumb hrptdata_noaa19a_thumb Update: This is an image of the L-band antenna he used.


  1. guest2

    What are the odds you could use a small ceramic patch antenna similar to those in GPS or Iridium devices to receive these signals?

  2. Mike

    Also, looking at the HackRF’s specs, it looks like it should be able to do both HRPT and CDMA easily! Too bad I missed the boat earlier. :(

    • admin

      Thanks for the info Mike. If you missed out on the HackRF kickstarter there’s always the BladeRF which is similarly speced and priced as the HackRF.

  3. Mike

    Everything I’ve read says that the RTL-2832U has a nominal SAMPLE rate of 2.8 megaSAMPLES per second–big difference from megaCYCLES. Under certain circumstances (I’ve somehow skimmed over what they are), it can be maxed out at 3.2 MSps. Since this is the sample rate for the A/D converter, your Nyquist limit is half that, thus 1.4 MHz nominal to 1.6 MHz max, and, for practical purposes, you should stay somewhat under this so we’ll call it 1 MHz (that’s 1,000 KHz for those of you who think HF is not DC :P). Also remember this is USB-2 so you’re limited by that as well as bus rate and contention since this is semi-realtime.

    In any case (and maybe Corgan can reply to this if he’s still watching) I’m guessing this is also the reason why GSM can be received, but CDMA (IS-95) can’t.

    Oh, and finally, the R820T and E4000 are the TUNER chips and only set where the device can tune; the problem here is almost certainly with the RTL-2832u itself.

    • Null

      You are correct in regards to the sample rate however they use quadrature sampling ( that is they take 2 sample and in phase and out of phase sample ). So the effective sample rate is actually 5.6 MSPS. By doing this you are able to increase the available bandwidth without increasing the sample clock. So yes the sample rate is 2.8 MSPS but correcting for the effects quadrature sampling the available bandwidth is also 2.8MHz with out violating the Nyquist rate.

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