IRIS Active Source Workshop Jan 29, 2014 Tucson AZ 125 Texan Recorder Data Storage

125 Texan circa 1997  Size of beer can - external geophone  D-Cell alkaline batteries  NAND Memory on PCB assembly –Initially 32 MByte –Eventually 256 MByte  Offload using special 1 Mbps serial –Effective rate of 100 KBps –45 minutes for 256 Mbyte  No Operating System –Interrupt driven task

125A Texan II circa 2005  Size of beer can - external geophone  D-Cell alkaline batteries  Embeded Linux OS  Embedded USB flash drive –256 MByte initial capacity –Eventually 1 GByte capacity  Hi Speed USB data transfer –480 Mbps –Effective rate depends on the USB drive  Current device ~40 MBps  Less than 1 minute for 1 Gbyte (~30 seconds) –.

Key limitations in 2005  Putting a MPU between the data storage device and the PC slowed the transfer –No Embedded MPU offered Hi Speed USB  Thru-put is limited by the USB, even though multiple devices can be copied simultaneously, effectively only one device is copied at a time  Implementation was to multiplex the USB drive between the slower embedded MPU and the PC.

S tate of the Art Data Storage Today  USB-3 5 Gbps – point to point and transfer speed is limited by the device 80 MBps consumer grade  USB-2 Industrial grade 40 MBps  Firewire 1-2 Gbps – p2p  SATA – 6 Gbps – p2p  SD Card – 90 MBps (Sandisk Extreme) 25 MBps Industrial grade (~3 min for 4 Gbyte – p2p

Possible data configuration  10 Gbps Ethernet Hubs –1 Gbps effective rate per connection  10 Gbps Network Access Storage  Dual CPU in recorder –Low Power CPU for data acquisition –Hi performance embedded Linux CPU that supports Gbps Ethernet and SD Flash storage  Or dual speed CPU –unlikely to find low enough power coupled with Gbps Ethernet.

Paul’s list from today for a new instrument  > data storage – 32 GB is available  1 vs 3 channels – increase in power  Reliability – keep it simple  Ease of deployment –Size –Weight –Limited configuration/field user interaction  Longer operating time – lower power  Time-keeping for longer duration  Raw data format

New Product for REF TEK Was not designed for Active Source – but has a lot of the features Self contained – no cables - preconfigured 3-channel – internal 2-Hz geophone Batteries for 7 days continuous recording and autonomous operation GPS timing M-SEED recording