Root API call's Q:?

1

Can I call the api to return a png?

I don’t see any documentation on the api.

I would like to get more precise with the return. specifically the most recent “payload_demod”: “https://network-satnogs.freetls.fastly.net/media/data_obs/3294428/data_3294428_2020-12-14T17-46-26.png” from my NOAA apt pass’s.

https://network.satnogs.org/api/observations/?id=&status=good&ground_station=984&start=&end=&satellite__norad_cat_id=&transmitter_uuid=&transmitter_mode=APT&transmitter_type=&waterfall_status=1&vetted_status=good&vetted_user=&payload_demod=1

Is it better to just write a post pass script to uploads it to my server?

2

There isn’t an API to return directly the image. You need to use the observations API endpoint and check the field demoddata to get the link to the image.

3

is there a document on the observations API endpoint?

4

Documentation is a work in progress. However browsing the https://network.satnogs.org/api/observations/ endpoint and using filters can give you some hints on how it works. If something is not very clear, let me know to help you.

5

I see the field demoddata Just wish I could use the api to return that field, so I can Wget files. Do you have any examples of code that uses the api’s return to find and download the file in the “payload_demod” field?

Q; think that :
“Start is greater than or equal to”
“End is less than or equal to”

Implies a date? in what format?

6

Here is some python example code that checks all the observations of one satellite from now back to a given date and prints all the payload_demod that it finds on these observations (maybe there are better ways to implement this but you can get an idea):

import json
import sys
import requests
import re
from time import sleep, gmtime, strftime
from datetime import datetime

try:
    norad_id = int(sys.argv[1])
except:
    print('Please give a valid norad id')
    sys.exit()

try:
    date = str(sys.argv[2])
except:
    print('Please give a valid date for example 2018-07-29T07:10:00Z')
    sys.exit()

status = ''
try:
    status = str(sys.argv[3])
except:
    pass

now = datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S")
url = 'https://network.satnogs.org/api/observations/?format=json&satellite__norad_cat_id=' + str(norad_id) + '&end=' + now

if status:
    url += '&status=' + status

next_url = url
while next_url is not '':
    print(strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime()))
    print("Requesting " + next_url)
    sleep(2)
    r = requests.get(next_url)

    if 'Link' in r.headers:
        if 'next' in r.headers['Link']:
            regex = r"<(.*)>.*next.*"
            next_url = matches = re.match(regex, r.headers['Link']).groups()[0]
            sleep(2)
        else:
            next_url = ''
    else:
        next_url = ''

    observations = json.loads(r.content.decode('utf8'))
    for observation in observations:
        obs_id = str(observation['id'])
        obs_start = observation['start']
        if obs_start > date:
            if observation['demoddata']:
              for datum in observation['demoddata']:
                  print(datum['payload_demod'], flush=True)
        if obs_start < date:
            print("Stop looking for next observations, last was obs: " + obs_id + "\n")
            exit(1)

Example how to run it (it may need to install some python packages):

python get_payload_demod.py 28654 2020-12-24T00:00:00Z good

In the example you can see how the date is formatted.

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