一、引言
JAVAD卫星定位系统是美国JAVAD(佳瓦特)公司在国际上最早推出的第四代GPS产品。北京合众思壮公司首次将其引入国内。由于该仪器具有GPS/GLONASS双系统双频跟踪能力，精度指标高，所以一经面世，便引起业界和用户的广泛关注。为检验该仪器的综合性能，石油物探局测量仪器检测中心于2000年1月4日至7日依据GPS检定规程，对该公司生产的三台Legacy(来格赛)卫星定位仪进行了检测，并根据检测结果提交了检定证书及测试报告，供有关部门参考。
二、仪器配置及主要技术指标
主机型号：Legacy (L00282 L00239 L00276)
天线型号：LegANT (LA0321 LA0318 LA0326)
跟踪信道：20个独立并行L1+L2通道，GPS/GLONASS兼具 ，可选
跟踪信号：L1/l2的C/A码、P码、载波
基线精度：1mm+0.1-1ppm
功耗：3瓦
主机重量：0.7公斤
主机尺寸：22.5cm×22.5cm×3.5cm
电源:外接 6-28VDC
电台：内置或外接均可
内存:16 Mb，可扩展为80Mb
三、系统软件及后处理软件
系统软件:Firmware V2.0
后处理软件:Pinnacle V1.0软件包
四、检定场地简介
石油物探局测量仪器检测中心的GPS检定装置已通过国家质量技术监督局标准考核并由河北省技术监督局授权。该中心具有边长2km的GPS检测小网和边长55km的中网以及边长13km的RTK测试网。小网的边长精度优于1/200万，每个点位都联测了国家一等水准点；中网基线点与国际GPS网进行了联测，具有精确的WGS-84坐标及BJ-54坐标，可对各种型号的GPS进行静态及动态检测。
五、精度测试
㈠静态测试
1．内部噪声
⑴ 测试方法及过程
内部噪声测试工作是在雪天进行的，三台仪器两个时段进行，基线处理采用JAVAD 随机软件Pinnacle和广播星历解算。解算过程未做任何人为干预。
⑵测试结果及精度分析
序号 基线值
m 实 测 值
m 误 差
mm 限 差
mm 备 注
1 0.3525 0.3526 0.1 1.0
2 0.3517 0.3519 0.2 1.0
内部噪声测试结果表明：实测精度满足仪器1mm的精度要求。
2．小网测试
⑴ 测试方法及过程
小网测试是在固城基线网上进行的，三台仪器分别安置在１号，2号，和5号点，同步观测1.5小时。基线处理采用JAVAD 随机软件Pinnacle和广播星历解算。解算过程未做任何人为干预。
⑵ 测试结果及精度分析
序号 基线值
m 实 测 值
m 误 差
mm 限 差
mm 备 注
1 24.0110 24.0109 0.1 1.0
2 456.0095 456.0100 0.5 1.0
3 480.0206 480.0209 0.3 1.0
小网测试结果表明：实测精度满足仪器标称精度要求。
2．中网测试
⑴ 测试方法及过程
中网测试是在石油物探局GPS检测网上进行的，三台仪器分别安置于WT00号点、WT02、和WT04，同步观测２.0小时。基线处理经JAVAD 随机软件Pinnacle和广播星历解算。解算过程未做任何人为干预。
⑵ 测试结果及精度分析
序号 基线值
m 实 测 值
m 误 差
mm 限 差
mm 备 注
1 11078.0263 11078.0365 10.2 11.1
2 40636.3338 40636.3213 12.5 40.6
3 47358.8968 47358.9032 6.4 47.4
中网的测试结果表明：实测精度满足仪器1mm+1ppm的精度要求。
㈡ 动态测试
1． RTK 实时动态精度测试
（1）测试方法及测试过程
1月6日我们进行了动态测试，按1+2组合。将基准站架设于GC01号点，输入该点的WGS-84坐标。流动站顺序观测于0、2、3、4、5、6号点，每点采集4组数据。
（2）数据处理及精度分析
外业实测数据的记录形式是WGS-84坐标，将各点的实时测量数与已知的坐标比较，即得出各点的误差值，统计如下表：
仪器号：L00239 仪器型号：Legacy 送测单位：北京合众思壮公司
点号Ｙ（测）△Ｙ(m)Ｘ（测）△Ｘ(m)Ｈ（测）△Ｈ(m)
6 390902.714 0.011 4334105.985 0.008 63.900 0.001
6 390902.711 0.014 4334105.984 0.007 63.899 0.002
6 390902.710 0.015 4334105.985 0.008 63.893 0.008
6 390902.714 0.011 4334105.987 0.010 63.895 0.006
5 390494.724 0.004 4334099.240 0.004 63.913 0.005
5 390494.724 0.004 4334099.238 0.006 63.914 0.006
5 390494.723 0.005 4334099.241 0.003 63.907 0.001
5 390494.728 0.000 4334099.243 0.001 63.906 0.002
4 390038.718 0.002 4334091.700 0.004 63.960 0.000
4 390038.717 0.003 4334091.703 0.007 63.964 0.004
4 390038.718 0.002 4334091.700 0.004 63.968 0.008
4 390038.719 0.001 4334091.702 0.006 63.963 0.003
3 389678.702 0.000 4334085.724 0.001 64.200 0.004
3 389678.698 0.004 4334085.729 0.006 64.202 0.006
3 389678.698 0.003 4334085.727 0.004 64.203 0.007
3 389678.698 0.004 4334085.726 0.003 64.207 0.011
2 389582.702 0.004 4334084.137 0.000 64.342 0.003
2 389582.700 0.006 4334084.139 0.002 64.339 0.000
2 389582.704 0.002 4334084.138 0.001 64.340 0.001
2 389582.701 0.005 4334084.139 0.002 64.341 0.002
0 389558.619 0.001 4334089.958 0.012 64.344 0.003
0 389558.620 0.002 4334089.957 0.013 64.342 0.001
0 389558.618 0.000 4334089.955 0.015 64.344 0.003
0 389558.619 0.001 4334089.957 0.013 64.344 0.003
±0.61(cm) ±0.73(cm) ±0.48(cm)
仪器号：L00282 仪器型号：Legacy 送测单位：北京合众思壮公司
点号 Ｙ（测） △Ｙ(m) Ｘ（测） △Ｘ(m) Ｈ（测） △Ｈ(m)
0 389558.618 0.000 4334089.957 0.013 64.333 0.008
0 389558.620 0.002 4334089.959 0.010 64.328 0.013
0 389558.619 0.001 4334089.958 0.012 64.338 0.003
0 389558.619 0.001 4334089.957 0.013 64.342 0.001
2 389582.702 0.004 4334084.137 0.000 64.332 0.007
2 389582.705 0.001 4334084.136 0.001 64.329 0.01
2 389582.700 0.006 4334084.139 0.002 64.331 0.008
2 389582.700 0.006 4334084.140 0.003 64.330 0.009
3 389678.696 0.006 4334085.731 0.008 64.200 0.004
3 389678.701 0.001 4334085.730 0.007 64.195 0.001
3 389678.700 0.002 4334085.733 0.010 64.205 0.009
3 389678.694 0.008 4334085.735 0.012 64.198 0.002
4 390038.717 0.003 4334091.700 0.004 63.970 0.010
4 390038.721 0.001 4334091.697 0.001 63.971 0.011
4 390038.723 0.003 4334091.692 0.004 63.971 0.011
4 390038.721 0.001 4334091.695 0.001 63.974 0.014
5 390494.721 0.007 4334099.253 0.009 63.899 0.009
5 390494.724 0.004 4334099.249 0.005 63.904 0.005
5 390494.719 0.009 4334099.251 0.007 63.901 0.007
5 390494.722 0.006 4334099.250 0.006 63.903 0.005
6 390902.714 0.011 4334105.985 0.008 63.890 0.011
6 390902.713 0.012 4334105.988 0.011 63.888 0.013
6 390902.714 0.011 4334105.985 0.008 63.889 0.012
6 390902.711 0.014 4334105.982 0.005 63.894 0.007
±0.65(cm) ±0.81(cm) ±0.89(cm)
从以上数据可以看出，测点最大平面误差1.6cm, 最大高程误差1.4cm。
2．电台通讯长度及RTK数据链质量测试
⑴ 测试方法及过程
将中心站架设在检测网E点上，将流动站分别安置在检测网F、G、H点上。每点采集几组数据。中心站至此三点的距离分别是：9.9km、 11.8km、 13.3km。
⑵测试结果及精度分析
点号 Ｙ（测） △Ｙ(m) Ｘ（测） △Ｘ(m) Ｈ（测） △Ｈ(m)
F 394051.586 0.008 4344083.662 0.018 69.128 0.015
F 394051.581 0.003 4344083.650 0.007 69.119 0.024
F 394051.590 0.012 4344083.660 0.017 69.129 0.014
F 394051.587 0.008 4344083.665 0.022 69.126 0.017
F 394051.583 0.005 4344083.652 0.008 69.138 0.005
F 394051.585 0.007 4344083.648 0.005 69.133 0.01
G 395420.168 0.022 4345664.549 0.007 69.528 0.059
G 395420.167 0.021 4345664.549 0.007 69.532 0.055
G 395420.164 0.017 4345664.548 0.007 69.536 0.052
G 395420.165 0.018 4345664.548 0.006 69.536 0.051
H 396720.481 0.005 4346591.178 0.000 70.145 0.001
H 396720.482 0.006 4346591.182 0.004 70.147 0.002
H 396720.480 0.003 4346591.182 0.004 70.151 0.005
H 396720.480 0.003 4346591.180 0.002 70.141 0.004
±1.23(cm) ±1.06(cm) ±3.19(cm)
从以上数据可以看出，此次测试电台通讯良好，数据链的通讯质量较高。测点最大平面误差2.2 cm ，最大高程误差5.9cm 。
六、其他性能测试
1． 该仪器内部噪声测试是在中雪中进行的，测试时仪器天线及主机均覆盖1cm厚的雪，而其结果仍能满足精度要求，说明该仪器具有很强的抗多路径干扰的能力。
2． 为了检验仪器的共同跟踪技术，我们将仪器天线置于距楼房2米的松林松枝中，仍可以稳定的跟踪卫星信号，取得实时固定解。说明该仪器对受到遮挡的低信噪比微弱卫星信号捕获能力很强。
3． 在距中心站13km的检测点进行RTK测试时，仪器初始化速度很快，信号稳定。
4． 为了检验仪器的抗电磁干扰能力，将其置于500KVA的变压器附近，可以得出RTK固定解。说明该仪器具有很强的抗电磁干扰能力。
七、结论
１．整个测试过程中仪器及配套设备均正常稳定工作。
２．由检测数据可以看出，该仪器可以满足1mm+1ppm的标称精度，是目前国内现有品牌中精度最高的仪器。
3．动态初始化速度较快，工作状态稳定。
4．该仪器具有GLONASS增强GPS功能，使可见卫星数增加，较其他仪器更适合于山区和城市等天空遮挡较严重的地区工作。
5．该仪器具有共同跟踪专利技术，对低信躁比卫星跟踪能力较强。
6．该仪器设计新颖，集成性好，操作简便。
7．功耗低，重量轻，适合野外工作。
8．该仪器具有4个RS232串口，一个高速并口，两个电源口，可满足多种GPS应用领域的需要。
9．后处理软件功能全面，界面丰富，操作简单。
10．由于时间仓促，对仪器的其他性能未进行更深入的测试。
参加测试人员：李明春 张继福 刘立军 岳永军 王立新
联系电话：010-69211981-55415
Aug. 6, 2003 — A Thai geneticist, a computer programmer and a music composer together have created a CD of music based o-n DNA sequencing.
While not a musical first, the CD, entitled "Genomic Music," was introduced at last month's Bio Thailand 2003 science fair and represents a somewhat surprising trend of DNA sequence patterns transformed into music. A handful of other gene-themed CDs has gone o-n the market in the past several months.
Sirasak Teparkum, a technical officer and public educator at The National Center for Genetic Engineering and Biotechnology in Thailand, decided to create the CD to provide musical accompaniment for a play celebrating the 50th anniversary of the discovery of DNA this year.
Teparkum searched databases to locate published DNA codes. He decided to focus o-n the genetic sequences for jasmine rice, an orchid, a cat, a dog, a shrimp, human hemoglobin, a human neurotransmitter, E. coli bacteria and the hepatitis virus B.
He then asked a computer programmer to write a program to decode each of the sequences. Teparkum used the program to convert the letter codes of DNA- A, T, C and G- into music notes. Since this o-nly resulted in four notes, he formed doublet pairings of DNA nucleotides to create o-ne sound resonance, which resulted in a total of 16 combinations and 16 sounds. For example, AA became low Do, AT became low Re, AC turned into low Me and so o-n.
"When I first heard my hepatitis song, all my hairs stood up," Teparkum told Discovery News. "The song was amazingly beautiful and it perfectly fit with my (play about DNA)."
Not everyone was so enthusiastic about the project.
Diana Deutsch, a professor of psychology at the University of California, San Diego, who conducts scientific research o-n music and has just released a CD entitled "Phantom Words and Other Curiosities," said Teparkum's music is "pleasant, but I think 99 percent of the music represents his (and the other creators') input."
She added, "He used DNA as an inspiration, but when o-ne listens to the music I do not believe that the sounds of DNA patterns are revealed. I asked an expert about this and was told that, due to the way protein folds, the genetic codes should have been grouped into threes instead of into twos."
Deutsch likened the genomic music more to the abstract algorithms used in several 20th century music compositions, where a mathematical pattern is altered in various ways to create music.
Teparkum still hopes that his work will help to bridge the gap between science and music.
"Science for some people is difficult and hard to understand; often they avoid it as much as possible," he said. "Therefore, I just hope that my genomic music could be used as a tool to reach out between the two distinctive fields of science and music to make things look (and sound) easier."
Aug. 6, 2003 — Italian scientists announced Wednesday they have succeeded in cloning a horse, raising the prospect of duplicating racing and show champions.
But the development, announced in the science journal Nature, was immediately denounced by two leading sporting organizations, the Jockey Club and the Thoroughbred Breeders Association.
Researchers at the Reproductive Technology Laboratory in Cremona fused skin cells with horses' eggs from which they had removed the nuclei. They created nearly 850 embryos, of which o-nly 22 reached the cell division stage.
Four mares were impregnated, but three aborted. o-ne produced a genetically identical copy of itself. The foal, born o-n May 28, was named Prometea and was said to be progressing normally.
The birth added to a list of animals that have been successfully cloned since Dolly the Sheep was born in Scotland in 1997, including mice, cattle, goats, rabbits, cats, pigs and recently, in the United States, a mule.
"In principle, cloning could enable gelding champions to contribute their genotype to future generations, as well as opening up an opportunity to verify the reproducibility of trains such as character and sporting performance," the Italian scientists said.
A gelding is a horse that has been castrated to improve certain performance characteristics, and which cannot be used for breeding.
Philip Freedman, chairman of the Thoroughbred Breeders Association, said the horse-cloning experiment was of "no value" to the racing community because a horse created by artificial insemination could not enter the stud books.
John Maxse of the Jockey Club said there was a consensus in the horse-racing community not to allow cloned horses.
"Sport should not be allowed to become a playground or amusement park for scientists," he said.
The Italian researchers are still trying to come to grips with o-ne aspect of their research. DNA tests showed that the original skin cell line from which the cloned foal was produced came coincidentally from its own mother. In other words, the mare produced an identical twin without setting off an immunological warning that would normally produce an abortion.
Until now, clones have always been produced by using surrogate animals.