FM Telemetry Data Format

Transcription

1 FM Telemetry Format For "SPROUT" CAM Revision A Date:2014/5/23 Authored Nihon University CubeSat Project Kento Ohinata 2014/5/23 Revision Revision Date Revised point Authored by A 2014/5/23 Kento Ohinata

2 Chapter List 1.Communicaiton Protocol FM Telemetry Format FM Downlink Structure Notification Introduction of CAM System CAM(Row data) CAM (thumbnail)...9

3 1.Communicaiton Protocol This is the protocol of FM communication of SPROUT. And, you need to see our HP to know which mode SPROUT is in now. Band rate and type SPROUT FM Downlink MHz 1200bps FM/AFSK 9600bps FM/GMSK MHz 1200bps FM/AFSK 2.FM Telemetry Format These is seven mode of SPROUT FM Telemetry. (1) Test FM Send real time sensor data by FM packet (2)CDH1 Sensing Send CDH1 sensor data which saved at FEPROM by FM packet. (3)INF Sensing (Pressure, Temperature) Send INF sensor data (Pressure Sensor, Temperature Sensor) which saved at FEPROM by FM packet. (4)INF Sensing (Piezo) Send INF sensor data(piezo Sensor) which saved at FEPROM by FM packet. (5)CAM Row Send camera data(row data) which saved at FEPROM by FM packet. (6)CAM Thumbnail Send camera data(compressed data) which saved at FEPROM by FM packet. (7)ADC Send ADC sensor data which saved at FEPROM by FM packet. This paper provide FM packet formant only "CAM(Row )" and "CAM(Thumbnail) sensing data" 2.1 FM Downlink Structure These are data structure for FM downlink except "Test FM". Call sing DBN TIM group CR FM Downlink Structure SPROUT>JQ1ZJQ: Block Number Time Group. group number for one sensing. Carriage Return "0X0D" Put sensing time is N(times). The data saved in FEPROM is below. And, satellite time is header of data structure. Group 1 Group 2 Group 3 Group N The data group saved in FEPROM This saved data group will send downlink by FM packet. The data quantity of data group and single packet is different. So, FM packet downlink such as this figure below.

4 T I M group 1 group 2 group 3 group N Call sign D B N T I M group 1 Part of grou p 2 C R Call sign D B N Part of group 2 Part of group 3 C R Call sign D B N 1 st packet DBN = 0x nd packet DBN = 0x rd packet DBN = 0x0002 The maximum data of single packet is 224[byte]. We use DBN( Block Number) method. The number of data group and single packet is not same quantity. So the data break into couple blocks. We call this bock is " Block". A DBN shows downlink packet number (This number is serial number which saved in FEPROM). Also, A satellite time shows time which is inside satellite. Each number formed hexadecimal number. This calculation is below. DBN TIM FM downlink calculation Group data Word(s) Mean Calculation DBN block number [blocks] TIM Satellite time ( )/10 [s] The satellite time gives only start of sensing. And, An interval time between sensing is only able to see at telemetry formant(chaper 3 testfm,4 CDH1 sensing). However, This cycle can change by us. So you have to see our web site to know this information. Usually, single packet is contain 224[byte] (448 worlds)for SPROUT. However, we can change packet number. You can see our website to know this information.

5 2.2 Notification There is 4 things have to be checked our web site to use FM telemetry. (1) Communication mode This shows FM communication mode. (2) Sensing start time Sensing start time is only give top of DBN. You can see our website to know FM sensing start time. (3) Sampling cycle The time between sensing(sampling cycle)is written on(chapter 3,4).But, this cycle is able to change. (4) Number of single packet This is the number(s) of byte contain single packet. Normally, this number is 224[byte](448 worlds). But it is able to change.

6 3. Introduction of CAM System The CAM system contains three sub system.(cam1,cam2,cam3). These three system is little bit different each other. The CAM1 and CAM2 has three FEPROM. Also, CAM3 has one FEPROM This CAM1 and CAM2 take photo maximum 14 photos. Also, CAM3 takes maximum 6 photos. And, The CAM1 and CAM2 takes photo at same period So TIM(exposure time) save only CAM1.(CAM2 use CAM1's TIM to take a photo). CAM3 takes photo as standalone unit. So, TIM save FEPROM on CAM3. CAM1 <ROM1> T I M Photo 1 Photo 4 <ROM2> Photo 5 Photo 6 Photo 9 <ROM3> Photo 10 Photo 11 Photo 14 CAM2 <ROM1> Photo 1 Photo 4 <ROM2> Photo 5 Photo 6 Photo 9 <ROM3> Photo 10 Photo 11 Photo 14 CAM3 T I M Photo 1 Photo 2 Photo 6 And, it is different satellite time(exposure time) which saved in CAM1 and CAM3. The single exposure time is 4byte = 8worlds. CAM1 CAM3 CAM System Exposure Time 14 shots = 56byte = 112 words 6 shots = 24byte = 48 words

7 The satellite time (exposure time) gives top of CAM1, ROM1 or CAM3.ROM data structure. The FEPROM gives 224[byte] capacity for saving satellite time. And, the photo data save after 224[byte]data(satellite time). Non TIM Photo 1 data 224 byte The length of satellite time is not 224 byte. So, we give Non data between TIM and photo data. The length of Non data is deferent CAM1 and CAM3. CAM System Non data CAM1 168byte = 336 words CAM3 200byte = 400 words To know the type of CAM subsystem(cam1,cam2,cam3) and ROM number has to check our website.

8 4. CAM(Row data) JQ1ZJQ>SPROUT: DBN 0x0D Callsign Satellite name Carriage return Block Number DBN CAM(Row ) Group Block Number Camera Group The calculation process of DBN( Block Number) shows to chapter 2.1. number except header call sign. This data formed hex (Total 4 words) Give the "0X0D" code at end single packet of downlink data A single data group represents 1 pixel for 2byte=16bit(4words). The photo data formed 16 bit color. The detail of RGB value is 5bit as R(red), 6bit as G(green), 5bit as B(blue). Also, size of photo is 640pixel 480 pixel

9 5. CAM (thumbnail) JQ1ZJQ>SPROUT: DBN 0x0D Callsign Satellite name Carriage return Block Number DBN CAM(thumbnail) Group Block Number Camera Group The calculation process of DBN( Block Number) shows to chapter 2.1. number except header call sign. This data formed hex (Total 4 words) Give the "0X0D" code at end single packet of downlink data A single data group represents 1 pixel for 2byte=16bit(4words). The photo data formed 16 bit color. The detail of RGB value is 5bit as R(red), 6bit as G(green), 5bit as B(blue). Also, size of photo is 640pixel 480 pixel. The height and width for thumbnail data is x pixel and y pixel. The relationship between this shows below. CAM Thumbnail Compressibility x [pixel] y [pixel] 1/ / / / / / The compressibility of data shows at our website.

10 Copy Right All copy right for this paper contribute to Nihon university "SPROUT project". In order to use this paper, we have to obtain copy right from us. Nihon university aerospace engineering department "SPROUT project". Room No. 232, 2F Building No.3, Funabashi campus, aerospace engineering department, Nihon university, Narashinodai, Hunabashi city, Chiba, Japan TEL: