Apollo Frequently Asked Questions (FAQ)

Question 1

Would it be possible to have a copy of the poles and zeros file for both the ALSEP short period instrument and long period instrument?


Please see the response function page where we have prepared the poles and zeros file for the short period and the long period seismometers. A0 values are also listed on the page.
There is a note on using these files. The LP seismometer has two operational modes: Flat and Peaked modes. Most of the observations were taken by the Peaked mode, but the Flat mode was also used sometimes.

Question 2

I have used Moon Seismic Monitor(obsolete) to download the Apollo seismic data. Is there a way to access the data directly within the database without going through the webpage interface?


You can download the data directly by using the following methods:

FORMAT: https://darts.isas.jaxa.jp/planet/seismology/apollo/dump/dump/{type}/START_TIME/{yyyy-mm-ddThh:mm:ss}/STOP_TIME/{yyyy-mm-ddThh:mm:ss}

"type" must be lp, sp, tidal, temp, and lspe.
Please set the time after "START_TIME" and "STOP_TIME" respectively.
The duration between "START_TIME" and "STOP_TIME" must be less than 3 hours, or time out will occur.

https://darts.jaxa.jp/planet/seismology/apollo/dump/dump/lp/START_TIME/1971-04-17T07:00:00/STOP_TIME/1971-04-17T09:00:00 ]

Question 3

What is the unit of the PSE for long period events? Centimeters or digital counts?


The unit of PSE LP data is digital counts.

Question 4

Have the Apollo Instrument corrections been performed by convolving the instrument response out of the raw data?


Our website does not provide calibrated data. Most scientists have been doing it themselves, through their own efforts. The following document is the most useful one to perform it: [Response]

Question 5

I would like the LPX, LPY, LPZ, SPZ for all the stations.
Can I download the entire dataset from somewhere?


As the entire dataset is huge, we recommend that you create the database from the raw files if you are familiar with Linux.

The raw files: [raw data]
And the software to extract it: [software]

Question 6

I have downloaded seismic data from the Moon Seismic Monitor(obsolete). What exactly do each of the columns in the ASCII files represent?


column 1: frame_count
The raw data are composed of 90 frames, and this is the counter of frames. The frame count cycles through 0 to 89. The detailed description is written in the UTIG Technical Report 118, here: [Tech Report 118.]

column 2: ap_station
This is apollo station No. (11,12,14,15,16,17)

column 3: ground_station
'ground_station' is the number that corresponds to NASA's Deep Space Network (DSN). You can find out the station name from here: [Data Correction]. Please see the Time Error Correction on the Ground Stations of the URL.

column 4: nc
One frame includes 64 words, and four data for Long Period Seismometer (LP). The following link may be helpful: [Quick Look]

column 5: time
The estimated time for the data.

column 6, 7, 8: lpx, lpy, lpz
The digital data of Long Period X, Y, Z. These values are raw data, and are normally used together with the response function, here: [Response]

Question 7

Is there a way to have the Passive Listening Mode data in LSPE to reanalyze it?


There are two ways to obtain the decoded data of LSPE.

1. Web Service API
The easiest way to obtain LSPE data is by using the following link. [Web Service API]
You can download an hour's data from the date time just after the START_TIME of the above link.

2. alsep_tools
You can download our software from the following link: [Software]. This tool includes decoder of High-Bit-Rate Work Tape file (the prefix is wth). The High-Bit-Rate Work Tape file is open here: [wth]
You can then decode the file like this:

$ wthinfo -rdf wth.1.1
#dp1: 144,124,120,124,128,136,128,128,128,128,128,128,128,128,126,122,122,108,124,126
#dp6: 136,134,128,128,118,116,114,116,126,132,128,128,136,128,126,124,136,128,128,136
#dp11: 136,134,138,134,128,128,128,128,128,128,128,128,128,128,128,128,132,128,134,136
#dp16: 128,132,134,166,138,136,194,130,128,128,128,110,160,128,128,128,128,166,138,138

The following URL might be useful if you wish to check if the data has been correctly decoded: [Quick Look]

To see the detailed info, please click the wths/wth.1.1 in the side menu.

Question 8

How do I analyze the Apollo seismic data from the beginning?


You need the relevant knowledge to analyze seismic data. Normally, the following steps are required:

1. Remove the offset
To delete the offset, calculate the average and subtract it from each value

2. Remove the trend
To delete the long-term trend, fit with the linear function and then subtract them

3. Convert the unit from DU to meter
Convert the unit from DU to meter using 1 LSB [V/DU] and response [V/m]

4. Perform the Fourier transformation
Change from the time-domain to frequency-domain by using Fourier transformation

5. Correct the seismometer response
Correct the seismometer response with the response function

6. Apply the filter
The Butterworth filter can be applied to extract the moon's seismic events effectively.

7. Perform the Inverse Fourier transformation
Change from frequency-domain to time-domain by using Inverse Fourier transformation

8. Perform despiking
To obtain a smooth seismic wave, perform despiking.
The median despiking algorithm might be used.

Question 9

Can I obtain the Apollo seismic data by using a generic format, such as SEED, SEGY, etc. from DARTS?


No, you can't. DARTS only provides the original raw format and decoded CSV data.

Question 10

Is it possible to download data from formats other than DARTS? Why should we use DARTS?


You can also obtain Apollo seismic data from IRIS or NSSDC. We know some of the Apollo 15 or 16 data is not on the IRIS website, and NSSDC does not have Apollo 11 seismic data. Our data was copied from the University of Texas in the 1990s, and it covers all of the data listed in the Technical Report 118.

However, IRIS and NSSDC are still available:

1. Incorporated Research Institutions for Seismology (IRIS):
You can download the Apollo data using the IRIS query form: [IRIS].
Please set the dataset name as "ALSEP". You can then find the generic seismic format of Apollo seismic data.

2. NASA Space Science Data Coordinated Archive (NSSDC) [NSSDC]

Question 11

Where can I obtain the orbit data from AKATSUKI?


The orbit data from AKATSUKI can be downloaded at the following URL:
[Akatsuki SPICE : Japanese]
[Akatsuki SPICE : English]

In the field of planet exploration, ancillary data such as orbit and attitude data use a format called SPICE, developed by NASA Jet Propulsion Laboratory (JPL). Data from HAYABUSA, KAGUYA, AKATSUKI, HISAKI, and HAYABUSA 2 are published in SPICE format. The data archived in SPICE format is called a SPICE kernel, which can be manipulated using the utilities and library published on the SPICE website. The orbit data are called the SPK (spacecraft and planet kernel) among the SPICE kernels.

Question 12

How can I convert the orbit data in SPICE format to ASCII format?


You can convert the data using the spkdiff utility on the SPICE website. Follow the three steps below:

STEP 1. Download the necessary data files.
STEP 2. Create a meta kernel.
STEP 3. Output the orbit using a tool.

The details of each step are as follows:

STEP 1. To convert the data from AKATSUKI, download the files at the following URLs:
https://darts.isas.jaxa.jp/pub/pds3/vco-v-spice-6-v1.0/vcosp_1000/data/(as below)

lsk/naif0012.tls ... Leap second.
pck/pck00010.tpc ... Constants, such as the radii of the planets and the moon.
spk/vco_de423_de430.bsp ... The orbits of the planets and the moon.
spk/vco_2017_v01.bsp ... The orbit of AKATSUKI (2017).

STEP 2. Create a "kernels.tm" text file (meta kernel) as stated below:

STEP 3. Run the spkdiff.
Download the spkdiff that is suitable for your operating environment at the following link: [LINK]
$ chmod +x spkdiff
$ ./spkdiff -k kernels.tm -b1 VCO -c1 EARTH -r1 J2000 -b 2017-04-01T00:00:00 -e 2017-04-02T00:00:00 -s 3600 -f 'YYYY-MM-DDTHR:MN:SC.### ::UTC'

In this example, the orbit of AKATSUKI seen from the Earth is displayed every 3,600 seconds at J2000 in the equatorial coordinate system. By changing Earth to Venus, the orbit of AKATSUKI seen from Venus can be displayed. Please refer to the SPICE website for further details.

Question 13

Are there any 3D spacecraft models available in DARTS?


Unfortunately, DARTS does not provide users with any 3D spacecraft models. It appears that in many cases, users create spacecraft models for themselves.

Question 14

How do I print the terrain data from KAGUYA using a 3D printer?


The most efficient way is to output the data in STL format using KADIAS. Currently, only some of the data are supported in STL format.

Below is an easy way of outputting "Elevation-TC" data in STL format:
1. Specify the range using the "Specify range" button.
2. Press the "Add layer" button. While "Elevation - TC" is selected, press the "Add layer" button.
3. Press the "Proceed to download mode" button.
4. Press the "Select layer to download" button, making sure that "Elevation - TC" is checked, and press the "Confirm" button.
5. Press the "Select download option" button and select "(C) Data for 3D printer (STL format)."
6. Set various parameters.
7. Press the "Download analysed file" button.
8. Wait until the "Download" button becomes valid and then press it.

Last Modified: 21 December 2020