Context: Although little was officially announced by Chinese authorities about the signals of the new system, the launch of the first COMPASS satellite permitted independent researchers not only to study general characteristics of the signals, but even to build a COMPASS receiver.

Question: How much information about the COMPASS system did Chinese authorities release?
Answer: little was officially announced

Question: What is one thing launching the first COMPASS satellite enable researchers to do?
Answer: to study general characteristics of the signals

Question: What is another thing launching the first COMPASS satellite enable researchers to do?
Answer: to build a COMPASS receiver

Question: How much information  about the new system's signals was released by Japanese authorities? 
Answer: Unanswerable

Question: What type of receiver did FBI researchers build?
Answer: Unanswerable

Question: The launch of the third COMPASS satellite allowed for researchers to do what?
Answer: Unanswerable

Question: How much information did Taiwanese authorities announce about the old system's signals?
Answer: Unanswerable