A Video Tutorial about Receiving HRPT Weather Satellite Images

Over on YouTube 'Tysonpower' has recently uploaded a very informative video and blog post showing how he is able to receive HRPT weather satellite images. Note that the video is in German, but English subtitles are provided.

Most readers of this blog are probably familiar with the more commonly received APT images that are broadcast by the NOAA satellites at 137 MHz, or perhaps the LRPT images also broadcast at 137 MHz by the Russian Meteor M2 satellite. HRPT signals are a little different and more difficult to receive as they are broadcast in the L-band at about 1.7 GHz. Receiving them requires a dish antenna (or high gain Yagi antenna), L-band dish feed, LNA and a high bandwidth SDR such as an Airspy Mini. The result is a high resolution and uncompressed image with several more color channels compared to APT and LRPT images.

In his video Tysonpower shows how he receives the signal with his 3D printed L-band feed, a 80cm offset dish antenna (or 1.2m dish antenna), two SPF5189Z based LNAs and an Airspy Mini. As L-band signals are fairly directional Tysonpower points the dish antenna manually at the satellite as it passes over. He notes that a mechanised rotator would work a lot better though. For software he uses the commercial software available directly from USA-Satcom.com.

[EN subs] HRPT - Erste Bilder! und mein Setup

An Example HRPT Image Received by Tysonpower.
An Example HRPT Image Received by Tysonpower.
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Anonymous
Anonymous

There is an article here you may be interested in that applies a loop Yagi antenna and a telescope mount for tracking: https://www.sdrplay.com/community/viewtopic.php?f=5&t=2624

Anonymous

That’s a perfect article on how to build the wrong antenna for the polarization required.

Anonymous

The article does mention that the loop Yagi antenna was used for HRIT/LRIT reception as well as HRPT, so you could figure there are bound to be some tradeoffs in a dual use solution. Cleary, it appears to be optimized for HRIT/LRIT linearly polarized operation with a secondary use for RHC polarized HRPT.

A. Judging from the images, it works quite well, even on the RHCP signals from polar orbital satellites.
B. It doesn’t require changing the antenna out for another one to receive the lower level HRIT/LRIT signals that are linearly polarized.
C. It doesn’t have a larger reflector required by an efficient helical antenna, so it fits into the low cost telescope mount without modifying the mount. The mount can then even be used with a telescope tube.

Perhaps it is not a perfect solution for HRPT, but it appears to have reasonable tradeoffs to save expense in using one setup for HRIT/LRIT and HRPT (plus astronomy when swapping out the antenna for the telescope tube). If you are going to apply a solution for HRPT only, you could always adapt an antenna such as the helical antenna developed by Arne Van Belle here: http://www.g-romahn.de/wxsat/download/helical.zip .

Tysonpower [Manuel]

I have read that article before and the helical method seems to be a great alternative.

The biggest difference is that both of them use a Special HRPT Receiver instead of a SDR. I would guess that the HPT137 Receiver is way more sensetive and better filtered than a 100$ SDR. Because of that i think that it is not possible to get a noise free Image with such a helical on a SDR.

I also find it more complicated to wind such a big helical including matching and so on then using a Dish. But i’m really curious if it would work with a SDR and a helical or YAGI as well.

Anonymous

The article with the loop Yagi antenna is using an SDR.

Tysonpower [Manuel]

Oh right…wow i really missed that? xD

Then it should be possible, but the RSP2 has some more filtering as it seems and is quite a bit more expensive. Curious if it also works with a Airspy Mini.

AD5NL

I’ve been sitting on a set up I put together, but never tested, for HRPT and Goes using a 0.9 meter offset dish, a helical feed (made mine with PVC, copper tape and and a piece of copper-clad PCB), an RTL-SDR and an LNA4ALL.

I have been hesitant to test because I thought my dish was too small for GOES and did not think manual pointing of the dish would work.

However, if others are having success I may try it. Will still need to get decode software though.

Also, I think for HRPT a cross-polarized yagi with maybe 12 elements would also likely have enough gain, and a yagi at 1.7 GHz is pretty tiny. I bet I could use some hobby servos to point such a thing.

Tysonpower [Manuel]

The 90cm Offset dish should work fine, but you Need a better SDR when you like to decode HRPT.
But you should be able to see the Signal at least with the RTL-SDR.
One LNA4ALL didn’t work that well in my Setup, but one of those SPF5189Z LNAs only cost around 7$, so it’s not a big deal i would say.

The Yagi idea is great, curious if it has enough gain.

Anonymous

Food for thought once you have a circularly polarized Yagi antenna:

1) Low Cost Alt-Az mount: https://www.ebay.com/itm/Celestron-Nexstar-102-GT-Computerized-Alt-Az-Mount-and-Hand-Control/272626149556?hash=item3f79c8e8b4:g:p8IAAOSw5VFWJzY7

2) Satellite Tracking Software for the Mount: http://www.heavenscape.com/index.html