# Identify GW with GPS time synchronization **URL:** \ **Category:** Gateways\ **Created:** [September 20, 2020, 7:27pm UTC](https://www.thethingsnetwork.org/forum/t/identify-gw-with-gps-time-synchronization/40033 "2020-09-20T19:27:47Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![E\_T](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/e_t/32/35697_2.png) [@E\_T](https://www.thethingsnetwork.org/forum/u/E_T)\ **Post date:** [September 20, 2020, 7:27pm UTC](https://www.thethingsnetwork.org/forum/t/identify-gw-with-gps-time-synchronization/40033/1 "2020-09-20T19:27:47Z")
Hello, is it possible to identify lorawan gateways wich use a GPS receiver for time synchronization? E\_T ---
**Author:** ![descartes](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/descartes/32/47220_2.png) [@descartes](https://www.thethingsnetwork.org/forum/u/descartes)\ **Post date:** [September 20, 2020, 7:34pm UTC](https://www.thethingsnetwork.org/forum/t/identify-gw-with-gps-time-synchronization/40033/2 "2020-09-20T19:34:57Z")
Not unless you can find it in the meta data - which I haven’t seen … ---
**Author:** ![E\_T](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/e_t/32/35697_2.png) [@E\_T](https://www.thethingsnetwork.org/forum/u/E_T)\ **Post date:** [September 20, 2020, 7:48pm UTC](https://www.thethingsnetwork.org/forum/t/identify-gw-with-gps-time-synchronization/40033/3 "2020-09-20T19:48:34Z")
Thank you! ---
**Author:** ![descartes](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/descartes/32/47220_2.png) [@descartes](https://www.thethingsnetwork.org/forum/u/descartes)\ **Post date:** [September 20, 2020, 8:38pm UTC](https://www.thethingsnetwork.org/forum/t/identify-gw-with-gps-time-synchronization/40033/4 "2020-09-20T20:38:04Z")
To expand on this, TTN doesn’t use a GPS to set the gateway location, it has to be set via the console ---
**Author:** ![arjanvanb](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/arjanvanb/32/46626_2.png) [@arjanvanb](https://www.thethingsnetwork.org/forum/u/arjanvanb)\ **Post date:** [September 21, 2020, 8:02am UTC](https://www.thethingsnetwork.org/forum/t/identify-gw-with-gps-time-synchronization/40033/5 "2020-09-21T08:02:06Z")
I surely get GPS-provided coordinates and altitude in the list of gateways in an uplink’s metadata. I also see those change slightly over time, especially the altitude. After someone changed the coordinates of many gateways years ago by, I think, sending status messages with fake coordinates, TTN has implemented some protection. But surely the GPS coordinates as sent in a gateway’s uplink message are used (and preferred) by TTN; see [Gateway GPS configuration in local\_conf.json](https://www.thethingsnetwork.org/forum/t/gateway-gps-configuration-in-local-conf-json/6176/4). Some locations include `"location_source": "registry"`, which made me _assume_ that lacking this attribute would indicate that the location provided by a gateway was used. However, even if a gateway provides a location, that still does not tell one if the gateway **truly** has a GPS, nor if that GPS is also used for time synchronization. (Aside: note that uplinks of gateways that use the MQTT protocol, like the Kickstarter The Things Gateway which does not have a GPS, [have not included coordinates since May 11th](https://www.thethingsnetwork.org/forum/t/gateways-dont-show-up-in-ttn-mapper-android-app/37993/3).) ---
**Author:** ![E\_T](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/e_t/32/35697_2.png) [@E\_T](https://www.thethingsnetwork.org/forum/u/E_T)\ **Post date:** [September 26, 2020, 8:36pm UTC](https://www.thethingsnetwork.org/forum/t/identify-gw-with-gps-time-synchronization/40033/6 "2020-09-26T20:36:29Z")
Thats a good hint. Thank you E\_T