Sharjahsat-1 images decoding

Regarding Observation 7092144

There was image transmitted apparently. Is someone able to get an image out of this?

So this is what I was able to get:)


What algorithm did you use to recover the image? Simply write to JPEG?

There are other observcations with more data, but most have less than 90 packets… not sure if this is enough to complete an image. However, the packet sizes seem to be huge so maybe the packets are just really large - that would explain the small packet numbers.

I cropped header from every packet. It have same length. For example, first packet have following header: 82 6C 64 AA 9E A6 E0 82 6C 60 AA 9E A6 61 03 F0 45 53 45 52 41 F6 10 00 00 00.
And then merged remaining data

This observation have also image in it. One might try to get an image from there.
I think resolution of an image is low, plus packet sizes are huge. So it wouldn’t take much packets to translate an image. Although if you lose one packet, you lose big chunk of image. It might result broken image every time

Nice. Looks like JFIF data in there

How are you downloading the data from the observation?

I just manually download frames from data page. There more efficient way to download from (sat entry - data tab). But for this situation i prefer to download manually.

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I came up with this script:

import requests
from bs4 import BeautifulSoup
import binascii

final_file = open("output_ss_1.bin", 'wb')

urls = []

URL = ""
page = requests.get(URL)

soup = BeautifulSoup(page.content, "html.parser")

results = soup.find_all("a", class_="data-link")

counter = 0
for i in results:
  print("Found " + results[counter]['href'])
  counter = counter+1

print("Downloading "+str(len(urls))+" packets.")

for i in range(len(urls)):
  x = requests.get(urls[i])
  text = x.content

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You can also use the endpoints.

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It appears that SS-1 (sorry I need to call it that :joy: ) sometimes transmits 4 separate binary counters sometimes?? They shift by one byte though :person_shrugging:

tres interesant…

@geoscan this also has a JFIF header


Can you please share your decoder? I’ll try one myself soon enough…

Good pass with lots of data. We should try to decode.

looks fantastic! Will try

@geoscan what type of demodulator are you using?

Which demodulator are we talking about?:slight_smile:

For the packets, I tried soundmodem with 9600bd GMSK but it didn’t work unfortunately

It is FSK 9k6 G3RUH AX.25, so you can use the UZ7HO hs_soundmodem version.

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