SMS Locators

in this lesson

New in July 2021

With this feature, you can quickly send a text that allows the recipient of that text to share their location on your CalTopo map.

Assuming that person has a cell signal and a gps-capable phone can open a link that they receive in a text and send their location to a saved CalTopo map. Then anyone viewing that map can see the location of the user.

Note: At this time this action is only available in the web browser. There is no SMS Locator function available in the mobile app.

Location accuracy for this feature is generally <75m.

Topics on this Page:

Initiating the Text

To use this new feature, you must:

  • Be a part of a team account subscription
  • Be working from a saved map.

As long as these conditions are met, you can go to +Add, choose “locator”, then choose SMS locator.

In the edit box that appears:

  • The Label box will be what shows up on the map, such as “subject” or “Joe Smith” or “mp.”
  • The target phone number is the cell phone number for the subject. Use the indicated format, with no spaces.
  • The Message field allows you to send a note along with the link. We highly recommend that you say that the text is being sent from Search and Rescue. Any note that will alert the person that they should click the link is important to include here.

Fill out the edit box.

Click OK to send the message. The user will receive a text message from a 530 area code. Their instructions are simple, and included in the webpage that opens when they click the link.

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The Text Recipient

The person receiving the text must:

  • Be able to receive a text,
  • Have a web browser on their phone
  • Have cellular data service

After they click the link in the text message and approve location sharing, they’ll get a webpage that looks like this. As long as the webpage is visible, the track will continue to update. As it updates the latitude and longitude will change as they move. If the phone sleeps so that you cannot see the page, location will stop reporting till the phone awakes and that page is visible. If they close the web page, they can reopen via the same link and it will report again.

Troubleshooting Location Sharing for the Recipient

Some users, especially those on iPhones, will need to take extra steps to send their locations due to privacy restriction setting in their phones.

To get the SMS Locator working, the user will need to change privacy settings on their selected browser to allow location services in that browser.

To do this on the iPhone, go to Settings / Privacy / Location Services then select your browser app and make sure it is NOT set to “Never”. You can select either “Ask Next Time” or “While using the App” (which is what I chose). I also allowed “Precise Location” but that may not be available on everyone’s device.

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Using and Editing the Track on Your Map

Once the person receiving the text activates the locator there will be a pop-up that will alert you. Note: If you close the browser or the map before the subject has activated the locator, you will not get the pop-up alert. When you see the alert click ok, then at any time you can click the App Track label and your map will center on the subject's location.

A pop-up will alert you when the subject activates the SMS Locator.

Much like using other locators or shared locations, the position can continue to update and will draw a track “tail” so that you can see where the person is moving to and about how fast, or if they are staying more or less in the same spot.

In this image we see the locator track for “Jane Smith” on the map, with its track. In the map objects column there is an app track and a locator object.

You can edit the app track like any other track - change the color or name, view the profile, etc. By clicking on the name of the locator object, you can view the status of the locator:

An active SMS Locator object looks like this when you click on the name of the object in the map object menu. .

Here you can also send a new message to the user. This is not the best way to send extensive information or have a conversation with the recipient. For that, you should text with the person as normal, or use the phone. However, if you need to re-send the link for any reason, or a new message to confirm for the user that you are sending it from Search and Rescue or similar, this is possible.

Bring in the Whole Team

Since the track is a map object, any team member can open the same map via the mobile app, and navigate to the subject.

Here we see a mobile app user finding the app track in the map items list. In the next image, the app user has their location turned on and is pointing more or less in the direction of the sms user.

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