GLONASS data and jailbroken iOS - ios

Question

Are there programmatic ways to access GLONASS satellite signal and position data on iOS on a jailbroken device? That is, are there private calls one can make on a jailbroken device, which return this data? (As far as what I've tried, I don't have a jailbroken device, so I can't try anything out yet, but I'm curious as to what is possible there. Thanks.)

Answer 1

Even if your device isn't jailbroken, you can still see what's available to a jailbroken device ... you just can't fully test it yet.
On your development Mac, you have the complete frameworks, public and private, and you can use something like class-dump (or class-dump-z) to inspect them.
Download class-dump, and then on your Mac, you can use a script like this (to dump all the headers out to a folder under /Users/Shared/Headers/):
#!/bin/bash
cd /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk/;
for FRAMEWORKS in Frameworks PrivateFrameworks; do
frameworklib=./System/Library/"${FRAMEWORKS}"
for frameworkpath in "${frameworklib}"/*.framework; do
frameworkdir="$(basename "${frameworkpath}")"
frameworkbin="${frameworkdir%.*}"
if [ -f "${frameworkpath}/${frameworkbin}" ]; then
echo "Framework: ${frameworkbin}"
mkdir -p /Users/Shared/Headers/5.0/${frameworkbin}
class-dump -H -o "/Users/Shared/Headers/5.0/${frameworkbin}" "${frameworkpath}/${frameworkbin}"
fi
done
done
Then, you'll be left with headers that show not just the publicly documented APIs, but the private ones, too. Both frameworks that are completely private, and the private parts of public frameworks.
Then, I'd just go to the root folder of where this script dumps out the .h files, and start grepping:
> find . -name '*.h' | xargs grep -i GLONASS
Sadly, that term (GLONASS) doesn't turn up in the 5.0 headers, but as it sounds like you understand this problem domain, you probably could find some better terms to search on.
Unfortunately, the headers just include method prototypes and data definitions. No documentation. So, where there are int parameters, for example, you may need to do some guessing as to what they mean.
But, such is the trial-and-error nature of discovering hidden device capabilities :)
Note: you certainly can test some private APIs on your own non-jailbroken phone, after discovering them with the above process. Other APIs, however, won't work without the device being jailbroken, the app getting out of its sandbox, or maybe having root privileges, or other entitlements.

Answer 2

Well, for starters you are looking in the right direction: if you don't jailbreak you'll have access to Core Location framework & API that can give you location, precision etc, but no info from GPS/GLONASS receiver (not even which of them was used to get location).
But before you go digging around inside framework: do you need to access build in GPS/GLONASS receiver or is external bluetooth one acceptable? Have a look http://itunes.apple.com/us/app/bluetooth-gps-status-tool/id422661436?mt=8

Answer 3

The iPhone 4S supports AGPS and GLONASS. I am under the believe that Core Location manages the lower level communication and that my app doesn't care whether the lat/long data is coming from US GPS satellites or Russian GLONASS satellites. Core Location will provide you the correct lat/long info regardless.
UPDATE: After rereading your question perhaps I misunderstood the question to begin with. I don't think you will be able to access the GLONASS satellite signal and position. But good luck with that!