Receiving signals but co-ordinates remain unchanged.

[r00tb3]

My smartphone is receiving signals but the location is undetected.

What might be the problem?

@osqzss

[Johsnon]

Hi, what SDR device is this? Hackrf? Is there an additional TCXO (=clock) installed? I had the same problem when using hackrf without that clock part (the internal clock of my hackrf wasn't precise enough).

[r00tb3]

Hi, what SDR device is this? Hackrf? Is there an additional TCXO (=clock) installed? I had the same problem when using hackrf without that clock part (the internal clock of my hackrf wasn't precise enough).

It's HackRF and I'm not using an external clock with the HackRF.

Will this work as it is compatible with HackRF & Nooelec sdr?

Also, will I need a passive GPS antenna?

[osqzss]

You can make one by yourself ;) https://github.com/osqzss/gps-sdr-sim/tree/master/extclk

[osqzss]

A simple dipole antenna works just fine. https://www.u-blox.com/sites/default/files/products/documents/GPS-Antenna_AppNote_%28GPS-X-08014%29.pdf

[r00tb3]

Following this setup I'm buying a passive GPS antenna, RF attenuator & TCXO Module.

Also, do I need the 30db attenuator as shown here?

What if I don't use the attenuator?

[osqzss]

It will disturb the GPS receivers in your neighborhood.

[r00tb3]

Hi, what SDR device is this? Hackrf? Is there an additional TCXO (=clock) installed? I had the same problem when using hackrf without that clock part (the internal clock of my hackrf wasn't precise enough).

Did you also change the antenna? Or just used an external clock of 10Mhz at pin 22 and it worked?

[b4cktr4ck2]

I'm having a similar issue where my car's GPS is receiving the signal but is not changing location. I'm using a HackRF with a TXCO module from NooElec, and an ANT500 in a controlled environment. The same occurs with my smartphone- I've turned off Wifi/Cellular/Bluetooth and when I launch Google Maps my location is not changed. I'm just broadcasting a static location, should I broadcast something else?

[ogord]

Hi, I have the same problem, but with LimeSDR. I use the next parameters: ./gps-sdr-sim -e brdc1850.19n -s 2500000 -l 35.170514,25.009579,100 -b 8 -o sim111.bin ./limeplayer -s 2500000 -b 8 -g 0.5 < ../sim111.bin Device configuration: os ubuntu 16.04 LimeUtil --info Version information: Library version: v19.04.0-gd20557de Build timestamp: 2019-07-04 Interface version: v2019.1.0 Binary interface: 19.04-1 SoapySDRUtil --info Lib Version: v0.8.0-gfe8dfd18 API Version: v0.8.0 ABI Version: v0.8 Install root: /usr/local Search path: /usr/local/lib/SoapySDR/modules0.8 Module found: /usr/local/lib/SoapySDR/modules0.8/libLMS7Support.so (19.04.0-d20557d) Available factories... lime Available converters...

• CF32 -> [CF32, CS16, CS8, CU16, CU8]
• CS16 -> [CF32, CS16, CS8, CU16, CU8]
• CS32 -> [CS32]
• CS8 -> [CF32, CS16, CS8, CU16, CU8]
• CU16 -> [CF32, CS16, CS8]
• CU8 -> [CF32, CS16, CS8]
• F32 -> [F32, S16, S8, U16, U8]
• S16 -> [F32, S16, S8, U16, U8]
• S32 -> [S32]
• S8 -> [F32, S16, S8, U16, U8]
• U16 -> [F32, S16, S8]
• U8 -> [F32, S16, S8

[r00tb3]

I'm having a similar issue where my car's GPS is receiving the signal but is not changing location. I'm using a HackRF with a TXCO module from NooElec, and an ANT500 in a controlled environment. The same occurs with my smartphone- I've turned off Wifi/Cellular/Bluetooth and when I launch Google Maps my location is not changed. I'm just broadcasting a static location, should I broadcast something else?

I guess you'll have to get a GPS antenna I doubt if ANT500 will work!!

[osqzss]

@r00tb3 The signal strength shown in your picture seems too low. They should be somewhere around 45dB. By the way, the nominal TX power of HackRF or any other SDR devices is very high. You can use ANT500 to transmit the GPS signal without any trouble.

[r00tb3]

I've mounted the TXCO module and a GPS antenna so now the spoofing attack works!!

[b4cktr4ck2]

Thanks @osqzss for confirming the ANT 500 will indeed work, I figured that made no sense why it wouldn't. I'll open a separate issue for my case.