DPAM: Programs for Aeromagnetic Survey Data Processing
Program Name | Function |
alog2asc |
Convert AIRLOGS airborne binary raw data into
ASCII file Format.
|
Parameters: |
log filename input binary data filename
output ASCII data filename |
|
xldam |
Generate DPAM line data file from airborne
ASCII raw data by 'alog2asc' making use of
Real-time GPS position data included, with calculation of IGRF residuals.
|
Parameters: |
log filename filename of survey line information data
output DPAM line data filename survey year
IGRF generation number thin-out ratio N (crop 1 out of N data)
|
Filename of input airborne ASCII raw data is specified in the
survey line information data. |
xldpn |
Generate DPAM line data file from airborne
ASCII raw data by 'alog2asc' and PostNav
GPS position data, with calculation of
IGRF residuals.
|
Parameters: |
log filename filename of survey line information data
output DPAM line data filename survey year
IGRF generation number thin-out ratio N (crop 1 out of N data)
|
Filenames of input airborne ASCII raw data and PostNav GPS position data
are specified in the survey line information data.
|
xldhg |
Generate HGAM line data file (similar to DPAM line
data) from helicopter-borne gradiometer AM (HGAM) data, making use of
HGAM bird-mag data and Real-time or PostNav
GPS position data, with diurnal correction by
GSmag data and calculation of IGRF residuals.
|
Parameters: |
log filename filename of survey line information data
Pos. data spec.: 0(PNAV-DGPS) or 1(Real-time)
input GSmag data filename output DPAM line data filename
survey year IGRF generation number
magnetic sensors vertical separation (m)
thin-out ratio N (crop 1 out of N data) |
Filenames of input HGAM bird-mag data and Real-time/PostNav GPS position
data are specified in the survey line information
data. |
despike |
Eliminate magnetic field spike noise in DPAM line data.
|
Parameters: |
log filename input DPAM line data filename
output DPAM line data filename |
|
dvcorr |
Correct for magnetic field diurnal variation in DPAM line data,
making use of GSmag data.
|
Parameters: |
log filename input DPAM line data filename
input GSmag data filename output DPAM line data filename |
|
ecomp |
Execute compensation of aircraft magnetic effect for DPAM CompBox line
data, using line data of CompBox flight itself. (Test purpose)
|
Parameters: |
log filename filename of DPAM CompBox data
output DPAM line data filename |
|
fcomp |
Execute compensation of aircraft magnetic effect for DPAM survey line
data, using DPAM line data of CompBox flight.
|
Parameters: |
log filename filename of DPAM CompBox data
filename of input DPAM survey line data
filename of output DPAM survey line data |
|
ggrid |
Generate magnetic field grid data from DPAM line data or equivalent,
by the method developed by Smith and Wessel [1990].
|
Parameters: |
log filename input AM line data file-type (*1)
input AM line data filename
Geodetic system of input data [WGS(1) or TYO(2)]
[if random file] data formatting parameter (*2)
effecting radius (km) areaname label
map projection coordinate number grid location parameters (*3)
output grid filename |
|
ggrids |
Generate grid data of magnetic field and observation altitude from DPAM
line data or equivalent, by the method developed by Smith and Wessel [1990].
|
Parameters: |
log filename input AM line data file-type (*1)
input AM line data filename
Geodetic system of input data [WGS(1) or TYO(2)]
[if WGS(1)] Altitude Reference [GRS(1) or Geoid(2)]
[if random file] data formatting parameter (*2)
effecting radius (km) areaname label
map projection coordinate number (NC)
[if NC>=200] Altitude Reference of output [GRS(1) or Geoid(2)]
grid location parameters (*3) output grid filename |
|
pframe |
Draw map of coordinates framework of survey area.
(For easier setting of grid location parameters.)
|
Parameters: |
log filename output PS filename areaname
map projection coordinate number Latitude/Longitude range
drawing parameter |
|
pltrk |
Draw trackline paths from DPAM line data or equivalent.
|
Parameters: |
log filename input AM line data file-type (*1)
input AM line data filename
Geodetic system of input data [WGS(1) or TYO(2)]
[if random file] data formatting parameter (*2)
output PS filename areaname map projection coordinate number
location parameters drawing parameters |
|
pchkdv |
Plot GSmag data.
|
Parameters: |
log filename input GSmag data filename
output PS filename |
|
pchkmag |
Plot magnetic total field data of DPAM/HGAM line data (in black).
|
Parameters: |
log filename
data type (0:DPAM, 1:HGAM(1st), or 2:HGAM(2nd))
input DPAM/HGAM line data filename output PS filename |
|
pchkres |
Plot IGRF residual (or difference) magnetic field data of
DPAM/HGAM/StdLIN line data (in blue).
|
Parameters: |
log filename
data type (0:DPAM, 1-3:HGAM(1st/2nd/diff), or 4:StdLIN)
input DPAM/HGAM/StdLIN line data filename output PS filename |
|
pchkcomp |
Plot IGRF residual magnetic field data before and after the compensation
of aircraft magnetic effect, for the output DPAM file from the process
ecomp/fcomp.
|
Parameters: |
log filename input DPAM line data filename
output PS filename |
|
xslin |
Convert various format line data
into StdLIN standard line data.
|
Parameters: |
log filename input AM line data file-type (*1)
input AM line data filename
Geodetic system of input data [WGS(1) or TYO(2)]
[if WGS(1)] Altitude Reference [GRS(1) or Geoid(2)]
[if generic random file] data formatting parameter (*2)
output StdLIN data filename
Geodetic system of output data [WGS(1) or TYO(2)]
[if WGS(1)] Altitude Reference [GRS(1) or Geoid(2)] |
|
xslina |
Extract StdLIN line data with averaged re-sampling
from DPAM line data.
|
Parameters: |
log filename input DPAM line data filename
Geodetic system of input data [WGS(1) or TYO(2)]
[if WGS(1)] Altitude Reference [GRS(1) or Geoid(2)]
time interval of averaged re-sampling (sec.)
output StdLIN data filename
Geodetic system of output data [WGS(1) or TYO(2)]
[if WGS(1)] Altitude Reference [GRS(1) or Geoid(2)] |
|
(*1) |
There are variations of file types of AM line data as follows:
1: DPAM survey line data, 2: AMDB-GSJ located line data,
3: AMDB-NEDO integrated located data, 4: StdLIN standard line data,
0: generic random point data.
The detail of generic random point data file is specified by the data
formatting parameter (*2). |
(*2) |
Data formatting parameter includes the unit [minute(1) or
degree(2)] of latitudes/longitudes, and the sequence numbers for
latitude, longitude, altitude (in m) and magnetic field (in nT) data
in the free-format data string. |
(*3) |
"grid location parameters" include Northing and Easting of
Southwest corner, mesh interval and number of mesh to the North, and
to the East. |
ASCII airborne raw data output from "alog2asc" (example)
//alog2asc v.2003-11-26 by T. Nakatsuka
//InputDataFilename: 030215_132849.B00
/AlogVersion 2.0200
/DateTime: 20030215 13:28:50.07 (JulianDay: 46)
/Date: 2003 - 02 - 15
/Time: 13 : 28 : 50+0.060
/SensorType: 0(Cesium)
/Flight#: 0
/CyclingInterval: 0.050 sec
/Analog0: slope= 1.000, offset= 0.000
/Analog1: slope= 1.000, offset= 0.000
/Analog2: slope= 1.000, offset= 0.000
/Analog3: slope= 1.000, offset= 0.000
/Analog4: slope= 1.000, offset= 0.000
/Analog5: slope= 1.000, offset= 0.000
/Analog6: slope= 1.000, offset= 0.000
/Analog7: slope= 1.000, offset= 0.000
/ FID SYSTIME t200 MAG FGx FGy FGz Ralt Balt AD6 AD7 AD8 UTC LAT LON ALT Q N
911.7 13:28:50.07 757.842 46654.164 -3.838 2.534 -0.757 -1.255 -0.010 -0.654 0.000 0.000 4.51931 35.25182 136.92375 16.85 1 7
911.8 13:28:50.13 757.877 46654.270 -3.838 2.532 -0.771 -1.230 -0.010 -0.635 0.000 0.000 * * * * * *
911.9 13:28:50.24 758.003 46654.295 -3.833 2.534 -0.781 -1.216 -0.010 -0.635 0.000 0.000 * * * * * *
912.0 13:28:50.29 758.027 46654.358 -3.833 2.532 -0.752 -1.245 -0.005 -0.625 0.000 0.000 4.51944 35.25182 136.92375 16.86 1 7
912.1 13:28:50.40 758.164 46654.469 -3.843 2.534 -0.771 -1.216 -0.005 -0.635 0.000 0.000 * * * * * *
.......
Ground station magnetic field data (example)
/Base: 46490 <-- Baseline value (nighttime value of quiet day) (*)
/Date: 20030215 <-- Date (8 columns of "yyyymmdd") (*)
130008 464795
130023 464802
130038 464795
130053 464803 <-- Acquired data from ground station magnetometer
130108 464805 <-- 6 cols Time "HHMMSS", 1 col space,
130123 464807 <-- and 6 cols magnetic field (in 0.1nT unit)
130138 464806
130153 464805
.......
(*) If Baseline value and/or Date is specified in the midst of file,
it is effective rearward.
PostNav DGPS / Real-time GPS position data
(example)
03:51:11.000 35.096095 137.635373 983.83
03:51:12.000 35.096319 137.635368 985.57
03:51:13.000 35.096544 137.635363 987.19
.......
05:14:46.00 36.440488 138.535838 1408.51
05:14:47.00 36.440488 138.535838 1408.50
05:14:48.00 36.440488 138.535838 1408.47
.......
All lines are GPS position data in free format consisting of UTC time,
latitude (in degrees), longitude (in degrees) and altitude (in m).
Time data must be in the form of "HH:MM:SS.tt".
Survey line information data (example)
=030217f1.asc 030217f1.pnav
220 095250 100100
210 100330 101000
200 101210 101950
.......
140 111210 112050
130 112340 113120
=030217f2.asc 030217f2.pnav
120 121300 122010
110 122235 122840
100 123105 123850
.......
Lines starting with '=' on the 1st column specify data file,
giving filenames of ASCII raw data and GPS position data.
(Prog. xldam does not require filename of GPS position data.)
All other lines are individual survey line information, i.e.,
Line name, Start time and End time separated by space.
(The time format is "hhmmss.tt", where ".tt" can be omitted.)
Various Line data File Format
There is variations of AM line data file formats, as follows.
1) DPAM line data file
2) AMDB-GSJ located line data file
3) AMDB-NEDO integrated located data file
4) StdLIN standard line data file
0) Generic random point data file
In the file format of 2 and 3, latitude and longitude values are referred to
WGS (World Geodetic System), and altitude values are elevation from the Geoid.
However, there is no such rule in other types of format, and the user has to
specify the sort of geodetic system, etc.
The format type 0 is one for manipulating general versatile data, and the
unit of latitude and longitude values and the sequence of each data are to be
specified. In this case, the data line must consist of mumeric data only, with
an exception that ":" is treated as a data seperator sama as a space.
Commonly, individual point data consists 1 line data, the 1st column of
which is a blank or the 1st digit of a value. To indicate the start of new
line with any attribute information, there is a header line starting with
"&", "#" or "%" at the 1st column. Also, there may exist some comment
lines starting with "#".
(Accordingly, the omission of lines starting with "&", "%" and "#" gives
the series of valid point data.)
StdLIN line data format (example)
# Areaname: Kobe-Kyoto
# Survey Date: 1995.12.07-12.27
&A-01
2079.0222N 8116.2764E 277.8m -45.1nT
2079.0405N 8116.3164E 278.5m -44.6nT
2079.0588N 8116.3564E 279.1m -44.4nT
.......
2087.3958N 8134.2559E 275.4m -48.3nT
2087.4158N 8134.2964E 275.4m -53.6nT
& C-2r
2088.2712N 8134.3799E 279.1m -44.9nT
2088.2563N 8134.3384E 279.3m -40.8nT
2088.2407N 8134.2964E 279.6m -40.1nT
.......
Lines starting with '#' are comment information, usually placed only at
the head of the file. (Never be placed among series of line data.)
Lines starting with '&' or '%' indicate the start of line data.
Line name (number) is described in 2nd-9th columns, and the form of
the rest is not restricted. (Starting time and number of data points
included are commonly described.)
In some cases, a line with no data points is defined for explicit
declaration of the end of file.
All other lines are data of individual points, consisting of Latitude
(in minutes), Longitude (in minutes), Altitude (in m), and Residual
magnetic anomaly (in nT) data, with the format (42 columns) of
format(f10.4, 1hN, f11.4, 1hE, f8.1, 1hm, f8.1, 2hnT).
DPAM line data format (example)
# Areaname: Ootoge
# Survey Date: 2003.02.17
&220 95250.00 100100.00
4188.6 20030217 95250.02 3 35.08857 137.71223 1033.2 46445.27 -50.13 -3.535 2.783 1.099 3170.02
4188.7 20030217 95250.09 3 35.08859 137.71223 1033.3 46445.02 -50.39 -3.525 2.783 1.108 3170.09
4188.8 20030217 95250.17 3 35.08860 137.71223 1033.3 46445.90 -49.51 -3.545 2.781 1.084 3170.17
.......
4946.6 20030217 100059.89 3 35.20598 137.71225 1258.3 46440.41 -115.48 -3.560 2.891 0.713 3659.89
4946.7 20030217 100059.95 3 35.20598 137.71225 1258.3 46439.93 -115.95 -3.555 2.874 0.708 3659.95
&210 100330.00 101000.00
5177.8 20030217 100330.09 3 35.20476 137.70676 1247.5 46418.68 -138.34 -3.281 -3.225 -0.249 3810.09
5177.9 20030217 100330.19 3 35.20473 137.70676 1247.4 46418.48 -138.52 -3.296 -3.230 -0.273 3810.19
5178.0 20030217 100330.29 3 35.20470 137.70677 1247.3 46418.52 -138.47 -3.286 -3.210 -0.288 3810.29
.......
Lines starting with '#' are comment information, usually placed only at
the head of the file. (Never be placed among series of line data.)
Lines starting with '&' or '%' indicate the start of line data,
describing Line name (number) and Start/End time.
Time data is double precision value in the form of "HHMMSS.tt".
All other lines are data of individual points (109 columns + LF).
format(f7.1, 1x,i8, 1x,f9.2, 1x,i2, 1x,f9.5, 1x,f10.5, 1x,f6.1,
* 2(1x,f8.2), 3(1x,f7.3), 1x,f9.2)
1) Fiducial number, 2) Date (yyyymmdd), 3) Time (HHMMSS.tt),
4) Data spec.(*), 5) Latitude (Deg.), 6) Longitude (Deg.),
7) Altitude (m), 8) Magnetic field (nT), 9) IGRF residual (nT),
10-12) Fluxgate 3 components values (V),
13) UTC seconds (from JST 09:00, minus before 9AM)
In case of output from ecomp/fcomp, following data related to the
aircraft magnetic field compensation are added with format (4(1x,f8.2)).
14) residual before compensation (tres),
15) correction for aircraft magnetic field (corr),
16) random variation component (rand),
17) linear trend component (trend),
[tres = corr + rand + trend]
(*) meaning of Data spec.(k) :
k = 4,5,6,7 : 5) Lat., 6) Long., 7) Alt. are from Real-time GPS
k = 0,1,2,3 : 5) Lat., 6) Long., 7) Alt. are from PostNav DGPS
k = 2,3,6,7 : 8) Mag.F, 9) IGRFres. are not diurnal corrected yet
k = 0,1,4,5 : 8) Mag.F, 9) IGRFres. are diurnal corrected already
k = 1,3,5,7 : 8) Mag.F, 9) IGRFres. are not AMF compensated yet
k = 0,2,4,6 : 8) Mag.F, 9) IGRFres. are AMF compensated already
Bird-mag data and Line data in Helicopter-borne gradiometer AM
(HGAM)
[ HGAM bird-mag data format ] (example)
.......
20051012 09:14:51.10 99999.99 46949.90
20051012 09:14:51.20 99999.99 46949.89
20051012 09:14:51.30 99999.99 46949.85
20051012 09:14:51.40 46781.33 46949.85
20051012 09:14:51.50 99999.99 46949.79
20051012 09:14:51.60 99999.99 46949.77
20051012 09:14:51.70 46795.16 46949.70
20051012 09:14:51.80 46850.40 46949.78
20051012 09:14:51.90 46851.73 46949.73
20051012 09:14:52.00 46851.76 46949.70
.......
Each data consists of Date (yyyymmdd), Time (HH:MM:SS.tt),
Total force magnetic field at 1st sensor (nT), and
Total force magnetic field at 2nd sensor (nT),
with the form (41 columns + LF) as follows.
format(1x, i8, 1x, i2,1h:,i2,1h:,f5.2, 1x, f9.1, 1x, f9.1)
[ HGAM line data format ] (example)
&F13 142618.00 152530.00
189303 20051012 142618.00 82 36.43241 138.42609 2285.5 46934.03 -58.27 46936.09 -56.09 -2.06
189304 20051012 142618.10 82 36.43238 138.42610 2285.4 46934.69 -57.58 46936.12 -56.03 -1.43
189305 20051012 142618.20 82 36.43235 138.42612 2285.4 46935.28 -56.97 46936.75 -55.38 -1.47
.......
224821 20051012 152529.80 82 36.42001 138.58405 2700.9 47043.23 112.45 47048.76 118.09 -5.53
224822 20051012 152529.90 82 36.42004 138.58408 2700.4 47043.27 112.47 47048.77 118.09 -5.50
224823 20051012 152530.00 82 36.42006 138.58409 2699.9 47042.84 112.02 47048.52 117.81 -5.67
&F23a 125215.00 130130.00
138808 20051013 125215.00 82 36.40794 138.52861 2771.7 47531.58 593.48 47536.52 598.54 -4.94
138809 20051013 125215.10 82 36.40793 138.52858 2772.0 47531.73 593.64 47536.70 598.73 -4.98
138810 20051013 125215.20 82 36.40791 138.52856 2772.3 47531.83 593.75 47536.73 598.77 -4.90
138811 20051013 125215.30 82 36.40790 138.52853 2772.6 47531.95 593.87 47536.86 598.90 -4.91
.......
Lines starting with '&' indicate the start of line data,
describing Line name (number) and Start/End time.
Time data is double precision value in the form of "HHMMSS.tt".
All other lines are data of individual points (102 columns + LF).
format(i7, 1x,i8, 1x,f9.2, 1x,i2, 1x,f9.5, 1x,f10.5, 1x,f6.1,
* 5(1x,f8.2))
1) Fiducial number, 2) Date (yyyymmdd), 3) Time (HHMMSS.tt),
4) Data spec.(*), 5) Latitude (Deg.), 6) Longitude (Deg.),
7) Altitude (m), 8) MagneticField-1(nT), 9) IGRFresidual-1 (nT),
10) MagneticField-2 (nT), 11) IGRFresidual-2 (nT),
12) Magnetic field difference (nT),
(*) Data spec.(k) :
k = 82 if position data is recovered by PostNav DGPS
k = 86 if position data is recovered by Real-time GPS
(not diurnal corrected yet, no need of AMF compensation)
This data has the form of a variation of DPAM line data.
It can be processed much the same as DPAM line, as far as dealing
with MagneticField-1 value.
When dealing with MagneticField-2 value, the file shall be processed
as a generic random point data file.
AMDB-GSJ line data format
Located line data file from GSJ digital data processing consists of
1 row of areaname
header and a repetition of line data blocks, and the line data block is
composed of 1 row
line header and repeated point data. The format of each data row is as
follows.
name | offset | cols | format |
Contents |
(Areaname Header) | |
- | 0 | 2 |
A2 | fixed string ‘## ’ |
- | 2 | 2 |
2X | (space) |
area | 4 | 8 |
A8 | Area name |
year | 12 | 8 |
F8.2 | Year of survey (as used for DGRF calculation) |
high | 20 | 6 |
F6.0 | Altitude in ft |
- | 26 | 2 |
A2 | fixed string ‘ft ’ |
(Line Header) | |
- | 0 | 2 |
A2 | fixed string ‘# ’ |
lnam | 2 | 8 |
A8 | Line name (aligned left) |
npt | 10 | 6 |
I6 | Number of point data included |
(Point data) |
(repeat npt times) |
isec | 0 | 8 |
I8 | Time in seconds (converted from DDHHMMSS string) |
alat | 8 | 9 |
F9.3 | Latitude in minutes (ITRF) |
alon | 17 | 9 |
F9.3 | Longitude in minutes (ITRF) |
tres | 26 | 8 |
F8.1 | DGRF residual magnetic value in nT after all corrections
|
AMDB-NEDO line data format
Integrated located data file of NEDO survey consists of 1 row of
areaname header and
a repetition of line data blocks, and the line data block is composed of
1 row line header
and repeated point data. The format of each data row is as follows.
name | offset | cols | format |
Contents |
(Areaname Header) | |
- | 0 | 2 |
A2 | fixed string ‘## ’ |
- | 2 | 8 |
A8 | fixed string ‘ NEDO
’ |
area | 10 | 8 |
A8 | Area name
(kyushu / tohoku / hokkaido / chubu / kanto / chugoku )
|
(Line Header) | |
- | 0 | 2 |
A2 | fixed string ‘# ’ |
lnam | 2 | 8 |
A8 | Line name (aligned right) |
npt | 10 | 6 |
I6 | Number of point data included |
(Point data) |
(repeat npt times) |
ifid | 0 | 8 |
I8 | Fiducial number |
isec | 8 | 6 |
I6 | Time of a day in seconds |
alat | 14 | 9 |
F9.3 | Latitude in minutes (ITRF) |
alon | 23 | 9 |
F9.3 | Longitude in minutes (ITRF) |
tair | 32 | 8 |
F8.1 | Magnetic field in the air in nT |
tmdv | 40 | 8 |
F8.1 | Magnetic diurnal variation in nT |
tcor | 48 | 8 |
F8.1 | Magnetic field in nT after diurnal correction
and level adjustment |
tres | 56 | 8 |
F8.1 | DGRF residual in nT after correction and adjustment |
irad | 64 | 5 |
I5 | Radio altimeter value in ft |
ibar | 69 | 5 |
I5 | Barometric altimeter value in ft |