Pulsar Voices

<strong>The data is sourced from CSIRO Parkes ATNF.</strong><strong>eg </strong>http://www.atnf.csiro.au/research/pulsar/psrcat/<strong>Feel the pulse of the universe</strong>We're taking signal data from astronomical "pulsar" sources and creating a way to listen to their signals audibly.Pulsar data is available from ATNF at CSIRO.au. Our team at #SciHackMelb has been working on a #datavis to give researchers and others a novel way to explore the Pulsar corpus, especially through the sound of the frequencies at which the Pulsars emit pulses.Link to project page at #SciHackMelb - http://www.the-hackfest.com/events/melbourne-science-hackfest/projects/pulsar-voices/The files attached here include: source data, project presentation, data as used in website final_pulsar.sql, and other methodology documentation. Importantly, see the Github link which contains data manipulation code, html code to present the data, and render audibly, iPython Notebook to process single pulsar data into an audible waveform file. Together all these resources are the Pulsar Voices activity and resulting data.<strong>Source Data;</strong>* RA - east/west coordinates (0 - 24 hrs, roughly equates to longitude) [theta; transforms RA to 0 - 360*]<br>* Dec - north/south coordinates (-90, +90 roughly equates to latitude i.e. 90 is above north pole, and -90 south pole)<br>* P0 - the time in seconds that a pulsar repeats its signal<br>* f - 1/P0 which ranges from 700 cycles per sec, to some which pulses which occur every few seconds<br>* kps - distance from Earth in kilo-parsecs. 1 kps = 3,000 light years. The furthest data is 30 kps. The galactic centre is about 25,000 light years away i.e. about 8kps.psrcatShort.csv = 2,295 Pulsars all known pulsars with above fields; RA, Dec, ThetapsrcatMedium.csv - add P0 and kps, only 1428 lines - i.e. not available for all 2,295 datapointpsrcatSparse.csv - add P0 and kps, banks if n/a, 2,295 linesshort.txt - important pulsars with high levels of observation (** even more closely examined)pulsar.R - code contributed by Ben Raymond to visualise Pulsar frequency, period in histogrampulsarVoices_authors.JPG - added photo of authors from SciHackMelb<b>Added to the raw data:</b>- Coordinates to map RA, Dec to screen width(y)/height(x)y = RA[Theta]*width/360; x = (Dec + 90)*height/180- audible frequency converted from Pulsar frequency (1/P0)Formula for 1/P0(x) -&gt; Hz(y) =&gt; y = 10 ^ (0.5 log(x) + 2.8)Explanation in text file; Convert1/P0toHz.txtTone generator from: http://www.softsynth.com/webaudio/tone.php- detailed waveform file audible converted from Pulsar signal data, and waveform image (and python notebook to generate; available):The project source is hosted on github at:<br>https://github.com/gazzar/pulsarvoicesAn IPython/Jupyter notebook contains code and a rough description of the method used to process a psrfits .sf file<br>downloaded via the CSIRO Data Access Portal at http://doi.org/10.4225/08/55940087706E1<br>The notebook contains experimental code to read one of these .sf files and access the contained spectrogram data, processing it to generate an audible signal.<br>It also reads the .txt files containing columnar pulse phase data (which is also contained in the .sf files) and processes these by frequency modulating the signal with an audible carrier.<br>This is the method used to generate the .wav and .png files used in the web interface.https://github.com/gazzar/pulsarvoices/blob/master/ipynb/hackfest1.ipynb A standalone python script that does the .txt to .png and .wav signal processing was used to process 15 more pulsar data examples. These can be reproduced by running the script.https://github.com/gazzar/pulsarvoices/blob/master/data/pulsarvoices.pyProcessed file at: https://github.com/gazzar/pulsarvoices/tree/master/webhttps://github.com/gazzar/pulsarvoices/blob/master/web/J0437-4715.pngJ0437-4715.wav | J0437-4715.png)#Datavis online at: http://checkonline.com.au/tooltip.php. Code at Github linked above. See especially:https://github.com/gazzar/pulsarvoices/blob/master/web/index.phpparticularly, lines 314 - 328 (or search: "SELECT * FROM final_pulsar";) which loads pulsar data from DB and push to screen with Hz on mouseover.<b>Pulsar Voices webpage Functions</b>:<br>1.There is sound when you run the mouse across the Pulsars. We plot all known pulsars (N=2,295), and play a tone for pulsars we had data on frequency i.e. about 75%.<br>2. In the bottom left corner a more detailed Pulsar sound, and wave image pops up when you click the star icon. Two of the team worked exclusively on turning a single pulsars waveform into an audible wav file. They created 16 of these files, and a workflow, but the team only had time to load one waveform. With more time, it would be great to load these files.<br>3. If you leave the mouse over a Pulsar, a little data description pops up, with location (RA, Dec), distance (kilo parsecs; 1 = 3,000 light years), and frequency of rotation (and Hz converted to human hearing).<br>4.If you click on a Pulsar, other pulsars with similar frequency are highlighted in white. With more time I was interested to see if there are harmonics between pulsars. i.e. related frequencies.<br><b>The Team</b>Michael Walker is: orcid.org/0000-0003-3086-6094 ; Biosciences PhD student, Unimelb, Melbourne.Richard Ferrers is: orcid.org/0000-0002-2923-9889 ; ANDS Research Data Analyst, Innovation/Value Researcher, Melbourne.Sarath Tomy is: http://orcid.org/0000-0003-4301-0690 ; La Trobe PhD Comp Sci, Melbourne.Gary Ruben is: http://orcid.org/0000-0002-6591-1820 ; CSIRO Postdoc at Australian Synchrotron, Melbourne.Christopher Russell is: Data Manager, CSIRO, Sydney.https://wiki.csiro.au/display/ASC/Chris+RussellAnderson Murray is: orcid.org/0000-0001-6986-9140; Physics Honours, Monash, Melbourne.Contact: [e-mail] for more information.<br><strong>What is still left to do?</strong>* load data, description, images fileset to figshare :: DOI ; DONE except DOI<br>* add overview images as option eg frequency bi-modal histogram<br>* colour code pulsars by distance; DONE<br>* add pulsar detail sound to Top three Observants; 16 pulsars processed but not loaded<br>* add tones to pulsars to indicate f; DONE<br>* add tooltips to show location, distance, frequency, name; DONE<br>* add title and description; DONE<br>* project data onto a planetarium dome with interaction to play pulsar frequencies.DONE see youtube video at https://youtu.be/F119gqOKJ1U<br>* zoom into parts of sky to get separation between close data points - see youtube; function in Google Earth #datavis of dataset. Link at youtube.* set upper and lower tone boundaries, so tones aren't annoying* colour code pulsars by frequency bins e.g. &gt;100 Hz, 10 - 100, 1 - 10, &lt;1 Hz

**本数据集源自澳大利亚联邦科学与工业研究组织（CSIRO）帕克斯天文台的澳大利亚望远镜国家设施（ATNF）。**
示例链接：http://www.atnf.csiro.au/research/pulsar/psrcat/
**感受宇宙的脉动**
我们从天文"脉冲星（pulsar）"源获取信号数据，并将其转换为可听觉播放的信号。
脉冲星数据可从CSIRO.au的ATNF获取。我们墨尔本科学黑客松（#SciHackMelb）团队开发了一套数据可视化（#datavis）工具，为研究人员及其他用户提供一种新颖的脉冲星数据集探索方式，尤其是通过脉冲星发射脉冲的频率所对应的声音来进行探索。
项目页面链接（#SciHackMelb）：http://www.the-hackfest.com/events/melbourne-science-hackfest/projects/pulsar-voices/

本附件包含以下内容：源数据、项目演示文稿、网站所用的`final_pulsar.sql`数据库文件，以及其他方法学文档。重要的是，可通过GitHub链接获取数据处理代码、用于展示数据并生成可听觉播放内容的HTML代码，以及将单颗脉冲星数据转换为可听波形文件的IPython笔记本（iPython Notebook）。所有这些资源共同构成了"脉冲星之声"项目及其产出数据集。

**源数据字段：**
* 赤经（Right Ascension, RA）：东西方向坐标（范围0-24小时，大致对应经度）[通过`theta`将RA转换为0-360°]
* 赤纬（Declination, Dec）：南北方向坐标（范围-90至+90，大致对应纬度，即+90为北极上空，-90为南极上空）
* P0：脉冲星重复发射信号的周期，单位为秒
* f：1/P0，即脉冲频率，范围从700次/秒至每隔数秒发射一次脉冲的极低频率
* 千秒差距（kilo-parsecs, kps）：脉冲星与地球的距离，单位为千秒差距。1千秒差距=3000光年。本次数据集最远的脉冲星距离为30千秒差距，而银河系中心距离地球约25000光年，即约8千秒差距。

* `psrcatShort.csv`：包含2295颗已知脉冲星的数据集，包含上述RA、Dec、Theta字段
* `psrcatMedium.csv`：在`psrcatShort.csv`基础上新增P0与kps字段，共1428条数据，即并非所有2295颗脉冲星都具备这两个字段的完整数据
* `psrcatSparse.csv`：同样新增P0与kps字段，缺失值以空值填充，共2295条数据
* `short.txt`：包含观测数据丰富、经细致研究的重要脉冲星列表
* `pulsar.R`：由Ben Raymond贡献的代码，用于以直方图形式可视化脉冲星频率与周期
* `pulsarVoices_authors.JPG`：SciHackMelb团队成员合影

**原始数据补充处理：**
* 坐标映射：将RA、Dec转换为屏幕的y/x坐标，计算公式为：`y = RA[Theta] * 宽度 / 360`；`x = (Dec + 90) * 高度 / 180`
* 可听频率转换：将脉冲星频率（1/P0）转换为人类可听的音频频率，转换公式为：`y = 10^(0.5 log(x) + 2.8)`，具体说明详见`Convert1/P0toHz.txt`文本文件
* 音频生成器参考自：http://www.softsynth.com/webaudio/tone.php
* 由脉冲星信号数据转换而来的详细可听波形文件与波形图像（生成所用的Python Notebook可获取）

本项目源代码托管于GitHub：https://github.com/gazzar/pulsarvoices
其中一份IPython/Jupyter Notebook包含了处理通过CSIRO数据访问门户（http://doi.org/10.4225/08/55940087706E1）下载的psrfits .sf格式文件的代码与方法简述。该Notebook包含实验性代码，可读取此类.sf文件并提取其中的频谱图数据，经处理后生成可听信号；同时，该Notebook还可读取包含柱状脉冲相位数据的.txt文件（此类数据同样存储于.sf文件中），并通过可听载波对信号进行频率调制来完成处理。此即为生成网页界面所用.wav与.png文件的方法。
具体Notebook链接：https://github.com/gazzar/pulsarvoices/blob/master/ipynb/hackfest1.ipynb
另有一个独立Python脚本可完成.txt文件到.png与.wav的信号处理，我们使用该脚本额外处理了15颗脉冲星的数据，可通过运行该脚本复现此过程：https://github.com/gazzar/pulsarvoices/blob/master/data/pulsarvoices.py
处理后的文件存放于：https://github.com/gazzar/pulsarvoices/tree/master/web
示例文件：https://github.com/gazzar/pulsarvoices/blob/master/web/J0437-4715.png、J0437-4715.wav | J0437-4715.png

#数据可视化在线页面：http://checkonline.com.au/tooltip.php。相关代码已在上文的GitHub仓库中提供，尤其需关注：https://github.com/gazzar/pulsarvoices/blob/master/web/index.php 中的第314-328行代码（或搜索"SELECT * FROM final_pulsar"），该部分代码从数据库加载脉冲星数据，并在鼠标悬停时显示对应赫兹频率后展示于页面。

**"脉冲星之声"网页功能：**
1. 鼠标悬停于脉冲星图标上即可播放对应声音：我们绘制了全部2295颗已知脉冲星的分布，为具备频率数据的脉冲星（约占总数75%）生成了可播放的音频提示音。
2. 点击左下角的星形图标，将弹出单颗脉冲星的详细音频与波形图像：团队中有两名成员专门致力于将单颗脉冲星的波形转换为可听wav文件，他们共生成了16份此类文件并搭建了完整流程，但团队仅来得及加载其中一份波形文件。若有更多时间，我们将加载全部16份文件。
3. 鼠标悬停于脉冲星图标上时，将弹出简要数据说明，包含位置（赤经、赤纬）、距离（千秒差距，1千秒差距=3000光年）以及自转频率（已转换为人类可听的赫兹值）。
4. 点击某颗脉冲星，其余频率相近的脉冲星将以白色高亮显示：我原本计划在有更多时间时，探索脉冲星之间是否存在谐波关联，即频率相关的现象。

**项目团队**
* 迈克尔·沃克（Michael Walker）：ORCID：0000-0003-3086-6094，墨尔本大学生物科学博士生
* 理查德·费勒斯（Richard Ferrers）：ORCID：0000-0002-2923-9889，澳大利亚国家数据服务（ANDS）研究数据分析师、创新价值研究员，墨尔本
* 萨拉特·托米（Sarath Tomy）：ORCID：0000-0003-4301-0690，拉筹伯大学计算机科学博士生，墨尔本
* 加里·鲁本（Gary Ruben）：ORCID：0000-0002-6591-1820，澳大利亚同步辐射装置CSIRO博士后，墨尔本
* 克里斯托弗·拉塞尔（Christopher Russell）：CSIRO数据管理员，悉尼，相关介绍：https://wiki.csiro.au/display/ASC/Chris+Russell
* 安德森·默里（Anderson Murray）：ORCID：0000-0001-6986-9140，莫纳什大学物理学荣誉学士，墨尔本
如需更多信息，请联系：[e-mail]

**待完成事项**
* 将数据集、说明文档与图像文件上传至Figshare并分配DOI：除DOI分配外已全部完成
* 新增概览图像选项，例如频率双峰直方图
* 按距离为脉冲星设置颜色编码：已完成
* 为观测数据最多的前三颗脉冲星添加详细音频：已处理16颗脉冲星的详细音频，但尚未加载至页面
* 为脉冲星添加对应频率的音频提示：已完成
* 添加悬停提示框以显示位置、距离、频率与脉冲星名称：已完成
* 添加页面标题与项目说明：已完成
* 将脉冲星数据投影至天文馆穹顶并支持交互播放脉冲星频率：已完成，相关视频可参见：https://youtu.be/F119gqOKJ1U
* 支持缩放天空区域以区分邻近的数据点——相关功能已在谷歌地球（Google Earth）的数据可视化中实现，详见YouTube链接
* 设置音频提示音的上下限阈值，避免生成刺耳的音频
* 按频率区间为脉冲星设置颜色编码，例如：>100Hz、10-100Hz、1-10Hz、<1Hz