Sample Rate Confirmation


#1

Hello, I am from YHS LEOIC. After the seminar yesterday, our group research the sensors we were planning on using for our code to see how it will comply with the 15kB limit to output data. We plan to use all 3 channels of the Magnetometer (16B per channel) and a light sensor (somewhere between 7 and 16B) such as Infrared or Ultra Violet. From what we were able to gather, we found that it would be approximately 55B per data intake, giving us 2 data intakes per equatorial orbit with a duration of a week. We were hoping to learn if our findings were in fact accurate, and if not, what would the amount actually be?
Cheers,
YHS LEOIC


Space Experiment Questions
#2

Hi, YHS LEOIC
You look perfect for getting two readings per orbit for a two week period and keep under the payload max.

Here are a few values to help everyone with estimating payload sizes related to orbits.

Orbital Period (satellite around earth): 97.6 minutes from: http://www.wolframalpha.com/input/?i=lemur-2+peter
Orbits per day 14.8 = (24 hours * 60 minutes) / 97.6 minutes
Data payload maximum = 15kB
Avg data point size = 10B
Number of experiment data points per payload = 1500

Your team is using 4 sensors ( X,Y & Z of the magnetometer and a light sensors). You can use the average data size 10B * 4 sensors that would give you approx. 40B per data intake.

2 (data intakes) * 40B (per data intake) * 14.8 (orbits per day) * 7 (days) = 8,288B = 8.2kB

Or with your more exactly (nice work!) calculated data size measurement 55B per data intake, 11.4kB

Thanks for the question
-Kevin


#3

Interesting! We are posting our questions as well(another thread) and estimating payload size is key
My question is: Are you planning to do this programatically? ie uploading code to read sensors or configure the sensors to record at specific times and send the readings kind rgds Ajit