1. Cloudland Instruments Hawkeye Executive Summary Compiled April 15th, 2016

2. Cloudland Instruments The SeaHawk Program Goal of program is to fly two high resolution ocean color instruments carried by two CubeSat Platforms –Clyde Space provides the CubeSat bus –Cloudland Instruments provides the Hawkeye Sensor Program is funded by the Gordon and Betty Moore Foundation The program is administered by Dr. John Morrison –Affiliated with the University of North Carolina – Wilmington –Details are available at http://www.uncw.edu/soconhttp://www.uncw.edu/socon

3. Cloudland Instruments Optical Parameters 120 meter pixel footprint on ground Minimum image size is 1800 pixels wide x 4000 rows tall x 8 bands –Maximum number of rows will be 6000 – nominally 96 seconds of data Angular swath width is 22.6 degrees Nominal 540 Kilometer orbit 8 spectral bands – derived from SeaWiFS bands Sensitivity comparable to SeaWiFS Unit is designed for smaller targets, such as: –Large lakes –Coastal zones –Bays and estuaries –rivers

4. Cloudland Instruments Field of View from 540 Km Orbit -Santa Barbara Channel MODIS image 1800 x 5000 pixels illustrated

5. Cloudland Instruments Practical Constraints Spacecraft is defined to be a CubeSat –Severe size limitations –Shorter lifetimes than larger satellites Money was limited for initial effort –“Off-The-Shelf” CCD arrays had to be used Custom arrays would have been too expensive and time consuming to obtain Guiding principle was to do the best we can in a small package with readily available parts Excellent performance can be obtained!

6. Cloudland Instruments Orbital Operation Parameters Nominal orbital height = 540 km –Ground speed is 7600 meters per second Data nominally collected between 10AM and 2PM local time Latitudes from +?? to –?? degrees will be surveyed Orbital lifetime of 1 year is baseline Lunar calibration is possible by rolling the spacecraft attitude No solar calibrator is planned

7. Cloudland Instruments Hawkeye Spectral Bands

8. Cloudland Instruments Pushbroom Linear Array Concept chosen as Baseline Linear array chosen is On-Semi (Kodak) KLI-4104 –Includes three rows of 4080 pixels, 10 microns square –Includes one row of 8160 pixels, 5 microns square Array is available with no RGB filter matrix over CCD sites Full well performance is good –120K electrons for Chroma arrays –110K electrons for Luma array Electronic shutter can be implemented We do not use Luma array in any way (but we do clock it)

9. Cloudland Instruments Overview of OnSemi KLI-4104 CCD Quad-Linear Array (G, R, B, L) High Resolution: Luma (Monochrome) Array with 5 um Pixels with 8,160 Count (Active Pixels) Luma Channel has 4 Outputs High Resolution: Color (RGB) Array with 10 um Pixels with 4,080 Count (Active Pixels). For our application we use CCDs with no RGB filter Each Color (Chroma) Channel has 1 Output Two-Phase Register Clocking Electronic Exposure Control is possible

10. Cloudland Instruments Overview of KLI-4104 Geometry KLI-4104 Linear Array Arrangement

11. Cloudland Instruments Sample Array Mounted inside SBIG STT Camera for Characterization

12. Cloudland Instruments Measurements of Prototype CCD Array and Subsystems AN SBIG STT-3200 was modified to support the a KLI-4104 Exposure time can be varied from about 5 ms to 100ms –Exposure actually takes place during camera readout Only one Chroma channel can be read out Other Chroma channels are clocked and amplifiers powered Luma array not tested

13. Cloudland Instruments Array Testing – A Hand-Scanned Picture from my Backyard * (4 Millisecond exposure time, F/22, 2000 x 6000 pixel crop) * Legacy calibration target added for continuity

14. Cloudland Instruments It Looks Better in Color, after some Rain! RGB Image is 1800 x 6000 pixels, Mechanically Scanned 3 times with Different Filters

15. Cloudland Instruments A Rotary Stage Scanned RGB Scene of the Santa Barbara Airport (Image is 1800 x 6000 pixels) Detail

16. Cloudland Instruments CCD Uniformity is the Largest Noise Source in this Prototype Image No flat field calibration has been applied here – only a dark subtraction. Only one channel was aggregated.

17. Cloudland Instruments CCD Blooming is another Important Problem to Consider F/11 F/8 F/5.6 Blooming Appearing

18. Cloudland Instruments Design Concept 8 Lens assemblies and 8 filters feeding light to 4 linear arrays, each with dedicated readout circuitry “Finderscope” 752x480 pixel array for attitude determination Shutter for dark frame collection One computer collects data Separate preamp used for every single CCD output Four sets of clock drivers are used Four 16 bit A/D converters, each with 3 channels, are used

19. Cloudland Instruments Lens Design Triplet lens with 45 mm focal length, F/5 (9.0 mm aperture) Max lens diameter is constrained to 20 mm by packaging limitations Field of view is +/- 11.3 degrees in extent Filter CCD Plane Lens elements (Scrambler Front to CCD is 66 mm length) Scrambler

20. Cloudland Instruments Optical Design Concept – Dual Optical Path Shown CCD Array Filter Lens assembly Scrambler

21. Cloudland Instruments Optical Design Concept – 4 Arrays

22. Cloudland Instruments Mechanical Design Concept Solenoids for shutter Circuit Cards Science Apertures Finderscope Aperture Interface to CubeSat Debug Port Shutter Vane

23. Cloudland Instruments A Shutter is used to Provide a Dark Frame Reference Immediately before Data Capture Strip to block light from CCD Solenoids Shutter Mask

24. Cloudland Instruments Payload Illustration Within Rails Without Rails

25. Cloudland Instruments Payload to Platform Interface 16x Rail Attachment (4 per rail) 4x End Plate attachment

26. Cloudland Instruments Instrument fits within CubeSat Envelope

27. Cloudland Instruments We have Constructed a Solid Model for Fit-Check Purposes

28. Cloudland Instruments Nominal CubeSat Configuration and Coordinate System

29. Cloudland Instruments Circuit Card Configuration CCD Board Analog Board Motherboard Picozed Board Interface Board Finderscope sensor

30. Cloudland Instruments Solid Model contains Prototype Circuit Boards to Check Cabling We needed to make sure it could be assembled!

31. Cloudland Instruments CCD Stack Assembly CCD Parts Stack, Top to Bottom Lightshield * CCD Pedestal CCD Board * Held in by two 2-56 flat head Phillips screws using two threaded swages.

32. Cloudland Instruments CCD Board supports CCDs, Buffer Amplifiers and Passive Filtering Components Board Includes: 4 CCDs. 3 Output buffer amplifiers per CCD. Filtering Components. 4 Connectors to Analog Board. 4 CCD temp sensors. Notes: Each CCD has it’s own signal connector to help ease routing. Each CCD has it’s own supply latch-up current monitoring and protection located on the mother board.

33. Cloudland Instruments Analog Board contains Preamplifiers, A/Ds and CCD Clock Drivers Top View Board Includes: 1 Connector to mother board. 4 A/Ds. 4 Connectors to CCD board. 3 Preamplifiers per CCD. 8 Clock Drivers per CCD. Notes: Each CCD has it’s own set of drivers to allow clocking flexibility.

34. Cloudland Instruments Xilinx Zynq System on a Chip is Current Choice for Control Computer Hardware ARM CPU and Peripherals (PS) Section FPGA (PL) Section Interconnect system between PS and PL Sections

35. Cloudland Instruments A COTS PicoZED Board is used for the Processor Board includes: ZYNQ ARM processor 1 GB DDR3 SDRAM 128 Mb for QSPI Flash 4 GB eMMC Flash Board Dimensions: 4.0 x 2.25 in 4.0 in length drives mechanical design Notes: Bottom side contains 3 connectors for all board I/O Top View Bottom View

36. Cloudland Instruments Motherboard Ties all the other Boards Together Top View Board Includes: 3 Connectors for PicoZed Interconnects. All System Power Supplies (not shown). Power Supply Monitoring. Shutter Solenoid Driver. Notes: All boards connect to Motherboard except CCD board. Connection to Finder Scope not shown. Most likely on upper left front or back side. Connection to analog board Connection to interface board

37. Cloudland Instruments Interface Board connects to Spacecraft Top View Board Includes: Spacecraft Interface Connector. Purposed High Density, 26 Pin D- Sub. Payload Debug Connector. Purposed High Density, 15 Pin, D- Sub. Spacecraft Connector Contains: Power Input Command and Control Serial Interface. Image LVDS Quad SPI Data Download Interface. Payload Debug Connector Contains: JTAG Interface to ZYNQ Processor. Gbit Ethernet Debug Port. Note: as of this date Clyde- Space has proposed a different interface geometry!

38. Cloudland Instruments “Finderscope” Assembly RG 830 Filter Lens Elements Micron 752x480 Pixel CMOS Sensor Field Of View

39. Cloudland Instruments Finder Scope is on a small Separate Board Board Includes: Area Array Image and socket. Power bypass filters. Flat Flex Connector. Notes: Flat Flex Cable used to connect Finder Scope to mother board. Micron CMOS Image Sensor socket requires extension (bump out) of the camera back cover. All parts fit on top layer.

40. Cloudland Instruments Finderscope images were collected along with Linear Array Images Lens focal length was 8 mm. Flight will be 11.5 mm.

41. Cloudland Instruments Flight Software was used to Collect Finderscope Images Four of the 12 images captured are shown to illustrate progression and overlap

42. Cloudland Instruments Thermal Considerations Heat sinking rails will be used on the Analog and Mother board. Heat sinking will be needed to dissipate heat from four CCDs. Additional heat sinking will be required on the PicoZed board due to heat produced by Zynq processor. We plan to create a heat sinking surface on main housing that contacts processor.

43. Cloudland Instruments Data Acquisition 8 Spectral Bands with 2 Bands per CCD 6000+ Rows per Image 16 Dark + 1800 16-Bit Light Pixels Per Band 222 MByte Raw Image Buffer 4.7 to 30+ ms Row Interval (16ms typical) 1:1, 2:1 and 4:1 Hardware Oversampling G, R & B Channels Aggregated with 32 Row Buffer (G[n] + R[n-9] + B[n-18])/3 Up to 12 Finderscope Images per Exposure 788 x 480 10-Bit Pixels 12 Telemetry Records per Exposure

44. Cloudland Instruments Data Acquisition Timeline (177 Seconds Total) Boot to Linux (30 sec) Launch and Initialize (3 sec) Setup Exposure (1 sec) Acquire Darks and 6000 Rows (100 Sec) Post Process Data (11 sec) Download to Spacecraft (estimated 30 Sec) Shutdown (6 Sec) Optional Commands: Save Image to Instrument Flash (44 Sec) Restore Image from Instrument Flash (32 Sec) Full Power

45. Cloudland Instruments Bilinear Gain will be used to Fit data Within 12 bit Range (0 to 4096 ADU)

46. Cloudland Instruments Compression of 12-bit Pixels into13-bit Codes To begin: Encode Pixel[0] into 13-Bits with msb 1 and 12-bit Value If Pixel[1] – Pixel[0] is +31 to -32 and If Pixel[2] – Pixel[1] is +31 to -32 then Encode into 13-bits with msb 0 and two 6-bit Deltas Else Encode Pixel[1] into 13-Bits with msb 1 Repeat: for all Pixels in the row (This scheme works well for low contrast scenes)

47. Cloudland Instruments Hawkeye Image File Format Single file is a stream of individual data records Loss of individual records doesn’t mean loss of entire image Interspersed data from multiple sources: Row based Spectral Band and Finderscope data including timestamps with millisecond precision Multiple sets of Telemetry data Multiple Image Parameter records (Date/time, Exposure, etc.) Indices and checksums reveal missing or invalid records Cloudland will supply a C library for decoding records Multiple downloaded copies with missing or damaged records could be merged to fill-in missing records