The EFM-100C sensor outputs 20 electric field strength measurements per second. The format is described on page 47 of the manual (see EFM-100C_Manual_121415.pdf). Example of the EFM-100C sensor output for one second:

$+00.65,0*CE

$+00.64,0*CD

$+00.64,0*CD

$+00.64,0*CD

$+00.64,0*CD

$+00.64,0*CD

$+00.64,0*CD

$+00.64,0*CD

$+00.65,0*CE

$+00.64,0*CD

$+00.65,0*CE

$+00.64,0*CD

$+00.65,0*CE

$+00.65,0*CE

$+00.65,0*CE

$+00.64,0*CD

$+00.65,0*CE

$+00.65,0*CE

$+00.65,0*CE

$+00.64,0*CD

The LD-250 sensor outputs status telemetry once per second. When a strike is detected, strike telemetry is outputted. If noise is detected, noise telemetry is outputted. The maximum noise level, above which noise telemetry is outputted, can be configured via the SQ command. The commands are described on page 17 and the telemetry formats on page 18 of the manual (see LD-250 User Manual 02232018.pdf). Example of the LD-250 sensor output, taken from the sensor at Cerro Pachón,  for one second:

$WIMST,0,0,0,0,000.0*42

No example of noise telemetry has been obtained since the query squelch setting has been set sufficiently high (level 1 of a maximum of 15) to suppress noise altogether. However, it may be prudent to make sure that the sensor code supports processing this kind of telemetry as well.

No example of strike detection has been obtained since no thunderstorm has passed Cerro Pachón yet since the sensor was installed. There already is a lightning event for ESS in ts_xml, which may be reused for this sensor. That may need rework of the XML though.

In an email exchange with Russell Owen we decided to

• Collect all EFM-100C data over a period of 1 second and then store one telemetry entry with the median electric field strength, the std dev and the max.
• Collect all LD-250 status data and store one telemetry entry. The telemetry are emitted at a rate of once per second.
• Compute strike alerts based on ts_config_ocs configuration settings for the distances and emit events for those. As soon as no strike has been detected for a configurable amount of time, an event with all zeros will be emitted to indicate that.
• Compute high electric field alerts based on ts_config_ocs configuration settings and time limits and emit events for those. As soon as the electric field strength drops below the threshold for a configurable amount of time, an event with all zeros will be emitted to indicate that all is safe again.

Collecting all data and computing the alarms will be done in a new ESS DataClient. The XML will be modified accordingly.

ts_config_OCS PR: https://github.com/lsst-ts/ts_config_ocs/pull/121

ts_ess_common PR: https://github.com/lsst-ts/ts_ess_common/pull/24

ts_ess_controller PR: https://github.com/lsst-ts/ts_ess_controller/pull/32

ts_ess_csc PR: https://github.com/lsst-ts/ts_ess_csc/pull/73

Partially reviewed by Russell but asking fora review so I can claim the SP. The code review will continue in the next sprint but I will not open a ticket for that.

completed task for SP at end of sprint.  Task will continue with new ticket in next sprint.