Meta Data Name: Safegraph POI Visits
Last Modified: 2/26/2021
Author: Andres Crucetta Nieto
Safegraph Point of Interest Data can be accessed via their COVID-19 data consortium signup.
Source is here via Safegraph.
The data was generated using a panel of GPS pings from anonymous mobile devices. We determine the common nighttime location of each mobile device over a 6 week period to a Geohash-7 granularity (~153m x ~153m). For ease of reference, we call this common nighttime location, the device's "home". We then aggregate the devices by home census block group and provide the metrics set out below for each census block group. [1]
The data for Point of Interest visits was used raw. We didn't end up adding it to the final US COVID Atlas, however, we still include the data-frame below for reference.
County Point of Interest Visits
| Variable | Variable ID in .csv | Description |
|---|---|---|
| FIPS Code (Join Column) | fips_code |
County level fips code to join to county geospatial data |
| Week | YYYY-MM-DD | Numer of devices moving into the county for that week |
To preserve privacy, we apply differential privacy to all of the device count metrics other than the device_count. This may cause the exact sum of devices to not equal device_count, especially for sparsely populated origin_census_block_group. Differential privacy is applied to all of the following columns: completely_home_device_count, part_time_work_behavior_devices, full_time_work_behavior_devices, delivery_behavior_devices, at_home_by_each_hour, bucketed_away_from_home_time, bucketed_distance_traveled, bucketed_home_dwell_time, bucketed_percentage_time_home. [1]
If as a result of the differential privacy applied:
device_count < part_time_work_behavior_devices + full_time_work_behavior_devices +completely_home_device_count or
device_count < sum(counts in bucketed_distance_traveled) or
device_count < sum(counts in bucketed_home_dwell_count),
we then increase the device_count to the applicable sum (this only occurs in census_block_groups with small device_counts).
n/a