Public broadcast satellite utilizing a dataflow endpoint (demodulated and decoded) - AWS Ground Station
Communication pathsAWS Ground Station configsAWS Ground Station mission profilePutting it together

Public broadcast satellite utilizing a dataflow endpoint (demodulated and decoded)

This example builds off the analysis done in the JPSS-1 - Public broadcast satellite (PBS) - Evaluation section of the user guide.

To complete this example, you'll need to assume a scenario -- you want to capture the HRD communication path as demodulated and decoded direct broadcast data using a dataflow endpoint. This example is a good starting point if you plan to process the data using NASA Direct Readout Labs software (RT-STPS and IPOPP).

Communication paths

This section represents Plan your dataflow communication paths of getting started. For this example, you will be creating two sections in your AWS CloudFormation template: Parameters and Resources sections.

Note

For more information about the contents of a AWS CloudFormation template, see Template sections.

For the Parameters section, you're going to add the following parameters. You'll specify values for these when creating the stack via the AWS CloudFormation console. 


Parameters:
  EC2Key:
    Description: The SSH key used to access the EC2 receiver instance. Choose any SSH key if you are not creating an EC2 receiver instance. For instructions on how to create an SSH key see https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/create-key-pairs.html
    Type: AWS::EC2::KeyPair::KeyName
    ConstraintDescription: must be the name of an existing EC2 KeyPair.

  ReceiverAMI:
    Description: The Ground Station DDX AMI ID you want to use. Please note that AMIs are region specific. For instructions on how to retrieve an AMI see https://docs.aws.amazon.com/ground-station/latest/ug/dataflows.ec2-configuration.html#dataflows.ec2-configuration.amis
    Type: AWS::EC2::Image::Id
Note

You need to create a key pair, and provide the name for the Amazon EC2 EC2Key parameter. See Create a key pair for your Amazon EC2 instance.

Additionally, you'll need to provide the correct region specific AMI ID, when creating the AWS CloudFormation stack. See AWS Ground Station Amazon Machine Images (AMIs).

The remaining template snippets belong in the Resources section of the AWS CloudFormation template. 


Resources:
  # Resources that you would like to create should be placed within the resource section.

Given our scenario to deliver a single communication path to an EC2 instance, you'll have a single synchronous delivery path. Per the Synchronous data delivery section, you must set up and configure an Amazon EC2 instance with a dataflow endpoint application, and create one or more dataflow endpoint groups. 


  # The EC2 instance that will send/receive data to/from your satellite using AWS Ground Station.
  ReceiverInstance:
    Type: AWS::EC2::Instance
    Properties:
      DisableApiTermination: false
      IamInstanceProfile: !Ref GeneralInstanceProfile
      ImageId: !Ref ReceiverAMI
      InstanceType: m5.4xlarge
      KeyName: !Ref EC2Key
      Monitoring: true
      PlacementGroupName: !Ref ClusterPlacementGroup
      SecurityGroupIds:
        - Ref: InstanceSecurityGroup
      SubnetId: !Ref ReceiverSubnet
      BlockDeviceMappings:
        - DeviceName: /dev/xvda
          Ebs:
            VolumeType: gp2
            VolumeSize: 40
      Tags:
        - Key: Name
          Value: !Join [ "-" , [ "Receiver" , !Ref "AWS::StackName" ] ]
      UserData:
        Fn::Base64:
          |
          #!/bin/bash
          exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
          echo `date +'%F %R:%S'` "INFO: Logging Setup" >&2

          GROUND_STATION_DIR="/opt/aws/groundstation"
          GROUND_STATION_BIN_DIR="${GROUND_STATION_DIR}/bin"
          STREAM_CONFIG_PATH="${GROUND_STATION_DIR}/customer_stream_config.json"

          echo "Creating ${STREAM_CONFIG_PATH}"
          cat << STREAM_CONFIG > "${STREAM_CONFIG_PATH}"
          {
            "ddx_streams": [
              {
                "streamName": "Downlink",
                "maximumWanRate": 4000000000,
                "lanConfigDevice": "lo",
                "lanConfigPort": 50000,
                "wanConfigDevice": "eth1",
                "wanConfigPort": 55888,
                "isUplink": false
              }
            ]
          }
          STREAM_CONFIG

          echo "Waiting for dataflow endpoint application to start"
          while netstat -lnt | awk '$4 ~ /:80$/ {exit 1}'; do sleep 10; done

          echo "Configuring dataflow endpoint application streams"
          python "${GROUND_STATION_BIN_DIR}/configure_streams.py" --configFileName "${STREAM_CONFIG_PATH}"
          sleep 2
          python "${GROUND_STATION_BIN_DIR}/save_default_config.py"

          exit 0


  # The AWS Ground Station Dataflow Endpoint Group that defines the endpoints that AWS Ground
  # Station will use to send/receive data to/from your satellite.
  DataflowEndpointGroup:
    Type: AWS::GroundStation::DataflowEndpointGroup
    Properties:
      ContactPostPassDurationSeconds: 180
      ContactPrePassDurationSeconds: 120
      EndpointDetails:
        - Endpoint:
            Name: !Join [ "-" , [ !Ref "AWS::StackName" , "Downlink" ] ] # needs to match DataflowEndpointConfig name
            Address:
              Name: !GetAtt ReceiverInstanceNetworkInterface.PrimaryPrivateIpAddress
              Port: 55888
          SecurityDetails:
            SecurityGroupIds:
              - Ref: "DataflowEndpointSecurityGroup"
            SubnetIds:
              - !Ref ReceiverSubnet
            RoleArn: !GetAtt DataDeliveryServiceRole.Arn

  # The security group that the ENI created by AWS Ground Station belongs to.
  DataflowEndpointSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Security Group for AWS Ground Station registration of Dataflow Endpoint Groups
      VpcId: !Ref ReceiverVPC
      SecurityGroupEgress:
        - IpProtocol: udp
          FromPort: 55888
          ToPort: 55888
          CidrIp: 10.0.0.0/8
          Description: "AWS Ground Station Downlink Stream To 10/8"
        - IpProtocol: udp
          FromPort: 55888
          ToPort: 55888
          CidrIp: 172.16.0.0/12
          Description: "AWS Ground Station Downlink Stream To 172.16/12"
        - IpProtocol: udp
          FromPort: 55888
          ToPort: 55888
          CidrIp: 192.168.0.0/16
          Description: "AWS Ground Station Downlink Stream To 192.168/16"

  # The placement group in which your EC2 instance is placed.
  ClusterPlacementGroup:
    Type: AWS::EC2::PlacementGroup
    Properties:
      Strategy: cluster

  # The security group for your EC2 instance.
  InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: AWS Ground Station receiver instance security group.
      VpcId: !Ref ReceiverVPC
      SecurityGroupIngress:
        # To allow SSH access to the instance, add another rule allowing tcp port 22 from your CidrIp
        - IpProtocol: udp
          FromPort: 55888
          ToPort: 55888
          SourceSecurityGroupId: !Ref DataflowEndpointSecurityGroup
          Description: "AWS Ground Station Downlink Stream"

  ReceiverVPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: "10.0.0.0/16"
      Tags:
        - Key: "Name"
          Value: "AWS Ground Station - PBS to dataflow endpoint Demod Decode Example VPC"
        - Key: "Description"
          Value: "VPC for EC2 instance receiving AWS Ground Station data"

  ReceiverSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      CidrBlock: "10.0.0.0/24"
      Tags:
        - Key: "Name"
          Value: "AWS Ground Station - PBS to dataflow endpoint Demod Decode Example Subnet"
        - Key: "Description"
          Value: "Subnet for EC2 instance receiving AWS Ground Station data"
      VpcId: !Ref ReceiverVPC

  # An ENI providing a fixed IP address for AWS Ground Station to connect to.
  ReceiverInstanceNetworkInterface:
    Type: AWS::EC2::NetworkInterface
    Properties:
      Description: Floating network interface providing a fixed IP address for AWS Ground Station to connect to.
      GroupSet:
        - !Ref InstanceSecurityGroup
      SubnetId: !Ref ReceiverSubnet

  # Attach the ENI to the EC2 instance.
  ReceiverInstanceInterfaceAttachment:
    Type: AWS::EC2::NetworkInterfaceAttachment
    Properties:
      DeleteOnTermination: false
      DeviceIndex: "1"
      InstanceId: !Ref ReceiverInstance
      NetworkInterfaceId: !Ref ReceiverInstanceNetworkInterface

  # The instance profile for your EC2 instance.
  GeneralInstanceProfile:
    Type: AWS::IAM::InstanceProfile
    Properties:
      Roles:
        - !Ref InstanceRole

You'll also need the appropriate policies, roles, and profiles to allow AWS Ground Station to create an elastic network interface (ENI) in your account. 


  # AWS Ground Station assumes this role to create/delete ENIs in your account in order to stream data.
  DataDeliveryServiceRole:
    Type: AWS::IAM::Role
    Properties:
      Policies:
        - PolicyDocument:
            Statement:
              - Action:
                  - ec2:CreateNetworkInterface
                  - ec2:DeleteNetworkInterface
                  - ec2:CreateNetworkInterfacePermission
                  - ec2:DeleteNetworkInterfacePermission
                  - ec2:DescribeSubnets
                  - ec2:DescribeVpcs
                  - ec2:DescribeSecurityGroups
                Effect: Allow
                Resource: '*'
            Version: '2012-10-17'
          PolicyName: DataDeliveryServicePolicy
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
              - groundstation.amazonaws.com
            Action:
            - sts:AssumeRole

  # The EC2 instance assumes this role.
  InstanceRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: "2012-10-17"
        Statement:
          - Effect: "Allow"
            Principal:
              Service:
                - "ec2.amazonaws.com"
            Action:
              - "sts:AssumeRole"
      Path: "/"
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess
        - arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceforEC2Role
        - arn:aws:iam::aws:policy/CloudWatchAgentServerPolicy
        - arn:aws:iam::aws:policy/service-role/AmazonEC2RoleforSSM

AWS Ground Station configs

This section represents Create configs of the user guide.

You'll need a tracking-config to set your preference on using autotrack. Selecting PREFERRED as autotrack can improve the signal quality, but it isn't required to meet the signal quality due to sufficient JPSS-1 ephemeris quality. 


  TrackingConfig:
    Type: AWS::GroundStation::Config
    Properties:
      Name: "JPSS Tracking Config"
      ConfigData:
        TrackingConfig:
          Autotrack: "PREFERRED"

Based on the communication path, you'll need to define an antenna-downlink-demod-decode config to represent the satellite portion, as well as a dataflow-endpoint config to refer to the dataflow endpoint group that defines the endpoint details.

Note

For details on how to set the values for DemodulationConfig, and DecodeConfig, please see Antenna Downlink Demod Decode Config . 


  # The AWS Ground Station Antenna Downlink Config that defines the frequency spectrum used to
  # downlink data from your satellite.
  JpssDownlinkDemodDecodeAntennaConfig:
    Type: AWS::GroundStation::Config
    Properties:
      Name: "JPSS Downlink Demod Decode Antenna Config"
      ConfigData:
        AntennaDownlinkDemodDecodeConfig:
          SpectrumConfig:
            CenterFrequency:
              Value: 7812
              Units: "MHz"
            Polarization: "RIGHT_HAND"
            Bandwidth:
              Value: 30
              Units: "MHz"
          DemodulationConfig:
            UnvalidatedJSON: '{
              "type":"QPSK",
              "qpsk":{
                "carrierFrequencyRecovery":{
                  "centerFrequency":{
                    "value":7812,
                    "units":"MHz"
                  },
                  "range":{
                    "value":250,
                    "units":"kHz"
                  }
                },
                "symbolTimingRecovery":{
                  "symbolRate":{
                    "value":15,
                    "units":"Msps"
                  },
                  "range":{
                    "value":0.75,
                    "units":"ksps"
                  },
                  "matchedFilter":{
                    "type":"ROOT_RAISED_COSINE",
                    "rolloffFactor":0.5
                  }
                }
              }
            }'
          DecodeConfig:
            UnvalidatedJSON: '{
              "edges":[
                {
                  "from":"I-Ingress",
                  "to":"IQ-Recombiner"
                },
                {
                  "from":"Q-Ingress",
                  "to":"IQ-Recombiner"
                },
                {
                  "from":"IQ-Recombiner",
                  "to":"CcsdsViterbiDecoder"
                },
                {
                  "from":"CcsdsViterbiDecoder",
                  "to":"NrzmDecoder"
                },
                {
                  "from":"NrzmDecoder",
                  "to":"UncodedFramesEgress"
                }
              ],
              "nodeConfigs":{
                "I-Ingress":{
                  "type":"CODED_SYMBOLS_INGRESS",
                  "codedSymbolsIngress":{
                    "source":"I"
                  }
                },
                "Q-Ingress":{
                  "type":"CODED_SYMBOLS_INGRESS",
                  "codedSymbolsIngress":{
                    "source":"Q"
                  }
                },
                "IQ-Recombiner":{
                  "type":"IQ_RECOMBINER"
                },
                "CcsdsViterbiDecoder":{
                  "type":"CCSDS_171_133_VITERBI_DECODER",
                  "ccsds171133ViterbiDecoder":{
                    "codeRate":"ONE_HALF"
                  }
                },
                "NrzmDecoder":{
                  "type":"NRZ_M_DECODER"
                },
                "UncodedFramesEgress":{
                  "type":"UNCODED_FRAMES_EGRESS"
                }
              }
            }'
  

  # The AWS Ground Station Dataflow Endpoint Config that defines the endpoint used to downlink data
  # from your satellite.
  DownlinkDemodDecodeEndpointConfig:
    Type: AWS::GroundStation::Config
    Properties:
      Name: "Aqua SNPP JPSS Downlink Demod Decode Endpoint Config"
      ConfigData:
        DataflowEndpointConfig:
          DataflowEndpointName: !Join [ "-" , [ !Ref "AWS::StackName" , "Downlink" ] ]
          DataflowEndpointRegion: !Ref AWS::Region

AWS Ground Station mission profile

This section represents Create mission profile of the user guide.

Now that you have the associated configs, you can use them to construct the dataflow. You'll use the defaults for the remaining parameters. 


  # The AWS Ground Station Mission Profile that groups the above configurations to define how to
  # uplink and downlink data to your satellite.
  SnppJpssMissionProfile:
    Type: AWS::GroundStation::MissionProfile
    Properties:
      Name: "37849 SNPP And 43013 JPSS"
      ContactPrePassDurationSeconds: 120
      ContactPostPassDurationSeconds: 60
      MinimumViableContactDurationSeconds: 180
      TrackingConfigArn: !Ref TrackingConfig
      DataflowEdges:
        - Source: !Join [ "/", [ !Ref JpssDownlinkDemodDecodeAntennaConfig, "UncodedFramesEgress" ] ]
          Destination: !Ref DownlinkDemodDecodeEndpointConfig

Putting it together

With the above resources, you now have the ability to schedule JPSS-1 contacts for synchronous data delivery from any of your onboarded AWS Ground Station AWS Ground Station Locations.

The following is a complete AWS CloudFormation template that includes all resources described in this section combined into a single template that can be directly used in AWS CloudFormation.

The AWS CloudFormation template named AquaSnppJpss.yml is designed to give you quick access to start receiving data for the Aqua, SNPP, and JPSS-1/NOAA-20 satellites. It contains an Amazon EC2 instance and the required AWS Ground Station resources to schedule contacts and receive demodulated and decoded direct broadcast data.

If Aqua, SNPP, JPSS-1/NOAA-20, and Terra are not onboarded to your account, see Onboard satellite.

Note

You can access the template by accessing the customer onboarding Amazon S3 bucket using valid AWS credentials. The links below use a regional Amazon S3 bucket. Change the us-west-2 region code to represent the corresponding region of which you want to create the AWS CloudFormation stack in.

Additionally, the following instructions use YAML. However, the templates are available in both YAML and JSON format. To use JSON, replace the .yml file extension with .json when downloading the template.

To download the template using AWS CLI, use the following command: 

aws s3 cp s3://groundstation-cloudformation-templates-us-west-2/AquaSnppJpss.yml .

You can view and download the template in the console by navigating to the following URL in your browser: 

https://s3.console.aws.amazon.com/s3/object/groundstation-cloudformation-templates-us-west-2/AquaSnppJpss.yml

You can specify the template directly in AWS CloudFormation using the following link: 

https://groundstation-cloudformation-templates-us-west-2.s3.us-west-2.amazonaws.com/AquaSnppJpss.yml

What additional resources does the template define?

The AquaSnppJpss template includes the following additional resources:

  • (Optional) CloudWatch Event Triggers - AWS Lambda Function that is triggered using CloudWatch Events sent by AWS Ground Station before and after a contact. The AWS Lambda Function will start and optionally stop your Receiver Instance.

  • (Optional) EC2 Verification for Contacts - The option to use Lambda to set up a verification system of your Amazon EC2 instance(s) for contacts with SNS notification. It is important to note that this may incur charges depending on your current usage.

  • Ground Station Amazon Machine Image Retrieval Lambda - The option to select what software is installed in your instance and the AMI of your choice. The software options include DDX 2.6.2 Only and DDX 2.6.2 with qRadio 3.6.0. If you want to use Wideband DigIF Data Delivery and the AWS Ground Station Agent, please see Public broadcast satellite utilizing AWS Ground Station Agent (wideband). These options will continue to expand as additional software updates and features are released.

  • Additional mission profiles - Mission profiles for additional public broadcast satellites (Aqua, SNPP, and Terra).

  • Additional antenna-downlink configs - Antenna downlink configs for additional public broadcast satellites (Aqua, SNPP, and Terra).

The values and parameters for the satellites in this template are already populated. These parameters make it easy for you to use AWS Ground Station immediately with these satellites. You do not need to configure your own values in order to use AWS Ground Station when using this template. However, you can customize the values to make the template work for your use case.

Where do I receive my data?

The dataflow endpoint group is set up to use the receiver instance network interface that part of the template creates. The receiver instance uses a dataflow endpoint application to receive the data stream from AWS Ground Station on the port defined by the dataflow endpoint. Once received, the data is available for consumption via UDP port 50000 on the loopback adapter of the receiver instance. For more information about setting up a dataflow endpoint group, see AWS::GroundStation::DataflowEndpointGroup.