You can use the Field Recording page anywhere, even when there is no mobile phone signal. You will need to have visited the page once when you have internet connection (Wi-Fi or mobile data) to ensure that it is available when offline. Go to trapper.azurewebsites.net. Bookmark this page. Now log in, and click on Field Recording at the top of the screen. Your phone is now ready for field use.
In the field, open your phone’s browser and go to the page you bookmarked. Navigate to Field Recording. Note that the words ‘GWCT trapper’ show in red when there is no connection, and ‘No Connection’ is shown at the bottom of the screen. When internet connection is lost, Trapper automatically switches to the Field Recording page and other menu items are disabled.
Select the beat you are going to check. The first trap in sequence in the beat will automatically be selected in the trap selection window, but you can change this either by using the pull-down list of traps, or by clicking the forward arrow.
Make sure GPS is on
When checking traps in the field, make sure the GPS system on your phone is switched on. The phone’s GPS system takes a few minutes to ‘acquire’ satellites and determine its position. Acquisition of location data is usually indicated by a flashing icon at the top of the screen; the icon stops flashing when the location has been determined. Accuracy may continue to improve over several minutes. Accuracy will be reduced where the phone’s ‘view’ of satellites is restricted, e.g. among buildings, in a deep gorge, or under trees in leaf. In such circumstances, the location recorded for your trap may be inaccurate, but this fact is noted against the record. Viewed on the map, this may seem confusing. We have not included the option to adjust the trap symbol on the map, because any location error due to satellite masking may be repeated on later visits. The app will only allow you to record data with a location stamp if you appear to be close to the location originally recorded.
If you suspect GPS inaccuracy may be a big issue in your case, the app GPS Status, downloadable free from Google Play Store for Android devices, will allow you to see what is going on in terms of satellites, which is quite fascinating in itself!
The GPS system in a phone is rather power-hungry, so you will notice appreciably shorter phone use per charge when you are using Trapper in the field. Most phones will nevertheless go a full day from fully charged.
How the GPS is used and what happens if there’s no GPS signal
The ‘Inspect’, ‘Deactivate’ and ‘Remove’ buttons will change colour to indicate when you are within the inspection distance for the trap selected on the screen. The meanings of the colours are:
| Green |
|
GPS OK and within inspection range for the selected trap |
| Amber |
|
GPS OK but outside inspection range for the selected trap |
| Red |
|
No GPS |
If you press any of these buttons while green or amber, the event will be recorded with a full time, date and location stamp. Pressing the button while amber will obviously be less satisfactory as evidence that you visited the trap.
If the device has not obtained a GPS location (buttons are red), you can still record your actions when the buttons are red, but no location data will be recorded, so the record gives no evidence that you actually visited the trap. If you are in the process of checking a sequence of traps, and locations are determined for the majority of those, the date and time ‘stamp’ would still provide strong evidence that you visited the trap, because the records are logged in sequence.
You can also use the Inspect, Deactivate and Remove buttons when they are amber (indicating GPS location obtained but out of range). This allows you to put things straight if you realise that you forgot to record a trap inspection while you were at a trap you visited earlier in the day. Obviously because your present location is no longer close to the trap, the record will not prove that you visited the trap, but given the sequence of records you have generated during your trap round, it will at least confirm that you were out and about.
The north arrow
Compass north is indicated by a red arrow. When you first use Trapper in the field, it’s advisable to check that the compass arrow points correctly to north. Some browsers fail to feed correct compass and phone orientation data to web pages such as Trapper. If you are using an Android device and find the compass direction is incorrect, try – as a first step – downloading Mozilla Firefox and using that as your browser. Firefox is free, very effective, and works reliably with Trapper.
If the north arrow does not swivel as you turn the phone, and your phone is relatively old, it’s possible that the phone does not support compass orientation. In this case, the red compass arrow will always point the same way relative to the screen. The direction arrow still indicates the trap direction relative to the compass arrow, but this is useful only if the phone is physically turned to point the compass arrow to north. Everything else on the Field Recording page will still work fine on these older phones. A few phones may show correct directions only in certain orientations (portrait, landscape left, landscape right, upside-down); if this is your situation, please contact us (support@trapper.ffrwd.net).
The direction arrow
The black on-screen arrow that indicates the (horizontal) direction of the next trap in your beat is only as good as the GPS data allow. Typically it will be most reliable when you are more than 20m from the trap. That will usually allow you to find the trap or snare, even if it was set by someone else. Don’t expect 1m accuracy! Also, bear in mind that if you move, the GPS system has to update your position before the direction arrow can be correct. This usually happens every few seconds, but in some circumstances the GPS may be much slower. Watch the screen-top GPS icon: if it’s flashing the position hasn’t yet been fixed.
Correct display of the direction arrow depends entirely on the browser conveying data from the phone’s operating system to Trapper. This varies even from one version of the browser software to the next. We have found that Firefox for Android works very well.