JSON Decode Error being raised testing orbdetpy

[OrbitalMechanic]

I have orbdetpy installed on a Mac Pro (2019) running Mac OS X ver. 10.15.3 (Catalina) under the Anaconda distribution (Python 3.7.6). In running the example posted on https://github.com/ut-astria/orbdetpy, and as listed below.

(base) user@Samuels-Mac-Pro examples % python run_tests.py
run_tests start : 2020-03-05 00:21:11
Simulating azel_sim_cfg.json
Simulating radec_sim_cfg.json
Simulating tle_sim_cfg.json
Simulating radar_sim_cfg.json
Simulating radec_sim_cfg.json
Simulating plate_sim_cfg.json
Fitting radec_od_cfg.json
Fitting radar_od_cfg.json
Fitting tle_od_cfg.json
Fitting azel_od_cfg.json
Fitting radec_od_cfg.json
Fitting plate_od_cfg.json
Fitting posvel_od_cfg.json
run_tests end : 2020-03-05 00:21:59

(base) user@Samuels-Mac-Pro examples % python
Python 3.7.6 (default, Jan 8 2020, 13:42:34)
[Clang 4.0.1 (tags/RELEASE_401/final)] :: Anaconda, Inc. on darwin
Type "help", "copyright", "credits" or "license" for more information.

from orbdetpy.simulation import simulate_measurements
simulate_measurements("radar_sim_cfg.json", output_file = "sim_data.json")
Traceback (most recent call last):
File "", line 1, in
File "/Users/user/opt/anaconda3/lib/python3.7/site-packages/orbdetpy/simulation.py", line 62, in simulate_measurements
resp = stub.simulateMeasurements.future(build_settings(config))
File "/Users/user/opt/anaconda3/lib/python3.7/site-packages/orbdetpy/rpc/tools.py", line 102, in build_settings
inp = read_param(param)
File "/Users/user/opt/anaconda3/lib/python3.7/site-packages/orbdetpy/init.py", line 29, in read_param
data = json.loads(param)
File "/Users/user/opt/anaconda3/lib/python3.7/json/init.py", line 348, in loads
return _default_decoder.decode(s)
File "/Users/user/opt/anaconda3/lib/python3.7/json/decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/Users/user/opt/anaconda3/lib/python3.7/json/decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

A JSON decode error occurred when I executed the command simulate_measurements("radar_sim_cfg.json", output_file = "sim_data.json").

Any thoughts on how to fix this problem?

Sam Dupree.

[Shiva-Iyer]

You need to either cd into the folder that contains radar_sim_cfg.json or pass the fully qualified path name to radar_sim_cfg.json as the first argument to simulate_measurements. Otherwise it will look for that file in your current working directory which is probably not where the json file is.