Android Phone Sensors Missing Data
Discussion around peculiarities of Android phone sensors, data incompleteness, known issues, work-arounds etc.
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https://github.com/RADAR-base/RADAR-Schemas/tree/master/specifications/passive
Values not recorded if unchanged
There are two data streams, the light sensor and battery level, that only record data if the value changes. Therefore the data is collected in very irregular intervals.
Night time values may get limited by Android
There is some indication that over the night Android makes assumptions around sensor activity variability and may limit the data collected.
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Environment Sensor → Light
Other → Battery
Other Android limitations
Android may be more aggressively limiting phone sensor data collection
RSD-13 Text Messages Contacts Status can be NULL
https://radar-base.atlassian.net/servicedesk/customer/portal/1/RSD-13
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it is not allowed to determine if OUTGOING messages ids are contacts (as far as we are aware, seems to be an API limitation)
see: source code https://github.com/RADAR-base/radar-android-phone/blob/master/src/main/java/org/radarcns/phone/PhoneLogManager.java#L260-L285
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Some of the contacts will later be know because the same hash value is seen in INCOMING, it may at that point be possible to add populate a TRUE value into some of the messages that previously were OUTGOING. See the image attached to the issue
FITBIT DATA Anomalies
Sleep stages Unknown
a bug in the sleep stage mapping, where the "wake" sleep stage is mapped to "UNKNOWN". So during analysis, any UNKNOWN sleep stage can be mapped to AWAKE.
The android_phone_usage_event data is sent by the passive app that does not know the categories of the apps and hence its empty.
This data is then processed and app categories are added from the playstore in the backend and output the data to android_phone_usage_event_output.
Both of them use the same schema.
The android_phone_usage_event_aggregated uses this android_phone_usage_event_output data as input and creates windowed phone usage events with duration of usage of each app.
There was a bug that caused the file name unknown_date.csv in android_phone_usage_event_aggregated data but it is fixed now so the files should be name by time now.
Also another point, the android_phone_usage_event_aggregated and android_phone_usage_event_output depends on streams application on the server which is stopped due to resource constraints on the backend. So this data may not be updated anymore. But you can easily calculate this data from the android_phone_usage_event and playstore HTML parsing.
As for the eventType it will only be "Foreground" or "Background" as stated in the schema doc. The others are added just in case if needed in the future.
For the user interaction these are as suggested by their names -