You can use the following snippets to start querying crash pings with STMO and BigQuery. Using these tools, you can quickly get counts and other information about crash pings that are submitted day-to-day.
The following example just counts all existing pings for a few days across several dimensions:
SELECT date(submission_timestamp) AS crash_date, count(*) AS crash_count FROM telemetry.crash WHERE date(submission_timestamp) >= DATE_SUB(CURRENT_DATE(), INTERVAL 7 DAY) GROUP BY crash_date
Although the total crash counts is not always useful, you may want to restrict a query to a channel or some other dimensions, and also facet the results. Therefore, you can add a few more fields to the SQL:
SELECT date(submission_timestamp) AS crash_date, normalized_os AS os, count(*) AS crash_count FROM telemetry.crash WHERE date(submission_timestamp) >= DATE_SUB(CURRENT_DATE(), INTERVAL 7 DAY) AND normalized_channel='nightly' GROUP BY normalized_os, crash_date
These are just initial examples. You can query across all the fields in a telemetry crash ping, which provides useful information about the crashes themselves. You can view a summary of the available fields in the STMO schema browser, referring to the documentation on the Firefox crash ping for more information where necessary.