The Amprobe TR-200 Temperature/RH Datalogger collected data inside its sunshield for 24 hours. Below is the data it collected. It appears the sunshield is letting the datalogger get hotter than the air temperature. So I may try to add an electric fan next.
Sunday, August 26, 2018
Saturday, August 25, 2018
UAVSonde for NearSys Station, 25 August 2018
Sunday, August 19, 2018
Diameter of a Lunar Crater
Using one of the moon images I recorded last night, I determined the diameter of one of its largest craters, Alphonsus.
Alphonsus is the circled crater of the moon. According to Wikipeda, this crater has a diameter of 73 miles.
The moon in my image has a height of 2366.5 pixels. The moon's polar diameter is 2,117.9 miles, or .895 miles per pixel for my image. I found the diameters by using Pythagorean Theorem on the X-axis and Y-axis location of the pixels.
Alphonus has a diameter of 88.2 pixels. At a scale of .895 miles per pixel, Alphonsus has a diameter of 79 miles in this image.
My calculation is 6 miles too large, or an error of 8%. One source of error is trying to locate the edge of the craters bottom when it is heavily shadowed. Also, a second error is due to the edges of the moon are a little fuzzy. They're fuzzy because the telescope has a wide angle view and the eyepiece doesn't properly focusing on the extreme edges.
Nonetheless, this is a more accurate diameter than if I had just guessed.
Alphonsus is the circled crater of the moon. According to Wikipeda, this crater has a diameter of 73 miles.
The moon in my image has a height of 2366.5 pixels. The moon's polar diameter is 2,117.9 miles, or .895 miles per pixel for my image. I found the diameters by using Pythagorean Theorem on the X-axis and Y-axis location of the pixels.
Alphonus has a diameter of 88.2 pixels. At a scale of .895 miles per pixel, Alphonsus has a diameter of 79 miles in this image.
My calculation is 6 miles too large, or an error of 8%. One source of error is trying to locate the edge of the craters bottom when it is heavily shadowed. Also, a second error is due to the edges of the moon are a little fuzzy. They're fuzzy because the telescope has a wide angle view and the eyepiece doesn't properly focusing on the extreme edges.
Nonetheless, this is a more accurate diameter than if I had just guessed.
Visibility for NearSys Station, 19 August 2018
Colorimeter for Lunar Images
I installed a Colorimetry app on my cellphone so my students can collect colorimeter data during a chemical reaction.
You see, Beer's Law states that the absorbance of a chemical in solution is proportional to it's (molar) concentration. So the more concentrated, the darker to solution appears.
A colorimeter measures the intensity of a particular color of light. So to use it in chemistry, you need to aim light of the opposite color through a colored solution. So for,example, measure the color of red light shining through a green-colored solution. If you measure the brightness of at least two known solutions (one being zero concentration), you can determine the concentration of other solutions of the same chemical.
Let's now turn this in a new direction. I wanted to measure the color/intensity of lunar maria and highlands. Maria are young lava flood plains (rich in basalt and dense) and highlands are older feldsic-rich scum that floated to the surface of the once molten moon.
Maria are darker than highlands. This is in fact very apparent when you look at the moon even with just your eyes. But could I actually make a measurement of this?
I pointed my new 16" dobsonian telescope at the moon on the 18th and focused it while wearing my glasses. Then I started the colorimeter app and pointed the cellphone at the moon. I also had a screen capture app running so I could record the results.
In the two pictures below, you can see that indeed the colorimeter app did detect the difference between lunar maria and highlands and quantify that difference. But I don't know how consistent this will be. I really need a bracket to hold the cellphone to the eyepiece while I record data.
By the way, the app is from Research Lab Tools and costs $0.99.
You see, Beer's Law states that the absorbance of a chemical in solution is proportional to it's (molar) concentration. So the more concentrated, the darker to solution appears.
A colorimeter measures the intensity of a particular color of light. So to use it in chemistry, you need to aim light of the opposite color through a colored solution. So for,example, measure the color of red light shining through a green-colored solution. If you measure the brightness of at least two known solutions (one being zero concentration), you can determine the concentration of other solutions of the same chemical.
Let's now turn this in a new direction. I wanted to measure the color/intensity of lunar maria and highlands. Maria are young lava flood plains (rich in basalt and dense) and highlands are older feldsic-rich scum that floated to the surface of the once molten moon.
Maria are darker than highlands. This is in fact very apparent when you look at the moon even with just your eyes. But could I actually make a measurement of this?
I pointed my new 16" dobsonian telescope at the moon on the 18th and focused it while wearing my glasses. Then I started the colorimeter app and pointed the cellphone at the moon. I also had a screen capture app running so I could record the results.
In the two pictures below, you can see that indeed the colorimeter app did detect the difference between lunar maria and highlands and quantify that difference. But I don't know how consistent this will be. I really need a bracket to hold the cellphone to the eyepiece while I record data.
Interesting color description. You'll notice the RGB values for the lunar highlands are higher than those for Lunar maria. |
Maria is darker than highlands, according to the colorimeter app. The screen capture app was set to vibrate when it captured an image, hence the blurriness of this capture. |
By the way, the app is from Research Lab Tools and costs $0.99.
Friday, August 17, 2018
24-hour Temperature and Relative Humidity for NearSys Station, 15 August 2018
I built a sunshield for the Amprobe temperature and relative humidity datalogger. So these data were recorded in the backyard. Interesting temperature spike and abrupt drop in the relative humidity near midnight.
Sunday, August 12, 2018
UAVSonde Data for NearSys Station, 11 August 2018
Wednesday, August 1, 2018
July Monthly Weather for NearSys Station
Below are the charts I generated for the weather conditions at NearSys Station.
The ground temperature has continued to rise as heat from the air above flows into the ground. |
No precipitation in the month of July. |
High pressure has dominated. |
The afternoon relative humidity has stayed comfortable in the 25% range. |
The air temperature has changed very little this month. We are at above average temperatures for the month of July. |
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