Metrics with Amazon CloudWatch - AWS Ground Station

Metrics with Amazon CloudWatch

During a contact, AWS Ground Station automatically captures and sends data to CloudWatch for analysis. Your data can be viewed on a graph or as source code in the Amazon CloudWatch console. For more information about accessing and CloudWatch Metrics, see Using Amazon CloudWatch Metrics.

AWS Ground Station Metrics and Dimensions

What metrics are available?

The following metrics are available from AWS Ground Station.

Metric Description

Es/N0

The signal to noise ratio.

Units: dBm (decibels relative to milliwatts)

BitErrorRate

The unrecoverable error rate on bits in a given number of bit transmissions. Bit errors are caused by noise, distortion, or interference

Units: Bits errors per unit time

BlockErrorRate

The error rate of blocks in a given number of received blocks. Block errors are caused by interference.

Units: Erroneous blocks / Total number of blocks

ReceivedPower

The measured signal strength in the demodulator/decoder.

Units: dBm (decibels relative to milliwatts)

What dimensions are used for AWS Ground Station?

You can filter AWS Ground Station data using the following dimensions.

Dimension Description

Channel

The channels for each contact include One, Two, I (in-phase), and Q (quadrature).

Polarization

The polarization for each contact include LHCP (Left Hand Circular Polarized) or RHCP (Right Hand Circular Polarized).

SatelliteId

The satellite ID contains the ARN of the satellite for your contacts.

Viewing Metrics

When viewing graphed metrics, it is important to note that the aggregation window determines how your metrics will be displayed. Each metric in a contact can be displayed as data per second for 3 hours after the data is received. Your data will be aggregated by CloudWatch Metrics as data per minute after that 3 hour period has elapsed. If you need to view your metrics on a data per second measurement, it is recommended to view your data within the 3 hour period after the data is received or persist it outside of CloudWatch Metrics.

In addition, any data captured within the first 60 seconds will not contain enough information to produce meaningful metrics, and will likely not be displayed. In order to view meaningful metrics, it is recommended to view your data after 60 seconds has passed.

For more information about graphing AWS Ground Station metrics in CloudWatch, see Graphing Metrics.

To view metrics using the console

  1. Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

  2. In the navigation pane, choose Metrics.

  3. Select the GroundStation namespace.

  4. Select your desired metric dimensions (for example, Channel, Polarization, SatelliteId.

  5. The All metrics tab displays all metrics for that dimension in the namespace. You can do the following:

    1. To sort the table, use the column heading.

    2. To graph a metric, select the check box associated with the metric. To select all metrics, select the check box in the heading row of the table.

    3. To filter by resource, choose the resource ID and then choose Add to search.

    4. To filter by metric, choose the metric name and then choose Add to search.

To view metrics using AWS CLI

  1. Ensure that AWS CLI is installed. For information about installing AWS CLI, see Installing the AWS CLI version 2.

  2. Create a CloudWatch agent configuration JSON file. For instructions on creating a CloudWatch agent configuration file, see Create the CloudWatch Agent Configuration File.

  3. List the available CloudWatch metrics by running aws cloudwatch list-metrics.

  4. Modify the JSON file you created in step 2 to match the SatellitID from your metrics.

    Note

    Do not reduce the Period field to a value under 60. AWS Ground Station publishes metrics every 60 seconds and no metrics will be returned if the value is reduced.

  5. Run aws cloudwatch get-metric-data with time periods of your passes and your CloudWatch agent configuration JSON file. An example is provided below.

    aws cloudwatch get-metrics-data –start-time 2020-02-26T19:12:00Z –end-time 2020-02-26T19:24:00Z –metric-data-queries file://metricdata.json

Metrics will be provided with timestamps from your contact. An example output of AWS Ground Station metrics is provided below.

{ “MetricDataResults”: [ { “Id”: “myQuery”, “Label”: “Es/N0”, “Timestamps”: [ “2020-02-18T19:44:00Z”, “2020-02-18T19:43:00Z”, “2020-02-18T19:42:00Z”, “2020-02-18T19:41:00Z”, “2020-02-18T19:40:00Z”, “2020-02-18T19:39:00Z”, “2020-02-18T19:38:00Z”, “2020-02-18T19:37:00Z”, ], “Values”: [ 24.58344556958329, 24.251638725562216, 22.919391450230158, 22.83838908204037, 23.303086848486842, 22.845261784583364, 21.34531397048953, 19.171561698261222 ], “StatusCode”: “Complete” } ] “Messages”: [] }