What Affects The Number of Positions?

We assume that the positions per day is affected by: 1) the density 2) the quality of the AIS device 3) the movments of the vessel

The movement of the vessel affects how frequently it will try to broadcast its location. Based on http://www.milltechmarine.com/faq.htm:

Class A: Ships Dynamic Conditions | Dual Channel Receiver | Single Channel Receiver
Ship at anchor or moored | 3 min | 6 min
SOG 0-14 knots | 10 sec | 20 sec
SOG 0-14 knots, changing course | 3.3 sec | 6.6 sec
SOG 14-23 knots | 6 sec | 12 sec
SOG 14-23 knots, changing course| 2 sec | 4 sec
SOG >23 knots | 2 sec | 4 sec
Ship Static Information | 6 min | 12 min

Class B:
Ships Dynamic Conditions | Dual Channel Receiver | Single Channel Receiver SOG < 2 knots | 3 min | 6 min
SOG > 2 knots | 10 sec | 20 sec
Ship Static Information | 6 min | 12 min

Class A: 1,2,3 Class B:


In [2]:
import time
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap
from matplotlib import colors,colorbar
import matplotlib
%matplotlib inline
import csv 
import math
from math import radians, cos, sin, asin, sqrt
from scipy import stats
import math
import cPickle # save the query results for later

In [ ]:
import bq  
client = bq.Client.Get()

In [182]:
def Query(q):
    t0 = time.time()
    answer = client.ReadTableRows(client.Query(q)['configuration']['query']['destinationTable'])
    print 'Query time: ' + str(time.time() - t0) + ' seconds.'
    return answer

In [223]:
q = '''
SELECT
  integer(FLOOR(first_lat*10)) lat_bin,
  integer(FLOOR(first_lon*10)) lon_bin,
  integer(FLOOR(avg_lat*10)) lat_bin_avg,
  integer(FLOOR(avg_lon*10)) lon_bin_avg,
  satellite_positions sat_positions,
  terrestrial_positions terrestrial_positions,
  positions_weighted,
  avg_speed,
  slow_pings
FROM
(SELECT
  mmsi,
  SUM( CASE WHEN speed = 0 OR (speed<=2 AND type IN (18, 19)) THEN 180 
     WHEN (speed > 0 AND speed <14 AND type IN (1,2,3)AND turn = 0 )
         OR (speed>2 AND type IN (18,19)) THEN 10 
      when speed>0 and speed<14 and type in (1,2,3) and turn !=0 then 3.3
      when speed>=14 and speed<23 and type in (1,2,3) and turn = 0 then 6
      when type in (1,2,3) and (speed>=23 or (speed>=14 and turn !=0)) then 2
      END) positions_weighted,
   first(lat) first_lat,
   first(lon) first_lon,
   avg(lat) avg_lat,
   avg(lon) avg_lon,
   max(lat) max_lat,
   min(lat) min_lat,
   max(lon) max_lon,
   min(lon) min_lon,
   avg(speed) avg_speed,
   sum(if( (speed=0 and type in (1,2,3)) or (speed<2 and type in (18,19)),1,0 )) slow_pings,
   sum( if(REGEXP_REPLACE(tagblock_station, 'u', '') IN ('rORBCOMM000',
        'rORBCOMM01',
        'rORBCOMM008',
        'rORBCOMM009',
        'rORBCOMM010'),1,0)) terrestrial_positions,
   sum( if(REGEXP_REPLACE(tagblock_station, 'u', '') not IN ('rORBCOMM000',
        'rORBCOMM01',
        'rORBCOMM008',
        'rORBCOMM009',
        'rORBCOMM010'),1,0)) satellite_positions,       
FROM
  [pipeline_normalize.20150101]
WHERE
  type IN (1,2,3,18,19) and lat is not null and lon is not null and speed is not null and turn is not null
group by mmsi
)
  where
  max_lat - min_lat <5
  AND (max_lon - min_lon < 10
    OR first_lon > 170
    OR first_lon < -170)
  AND mmsi IN (select mmsi from
[scratch_david_gapanalysis.good_mmsi_2015_1000pings])
'''

positions = Query(q)


Waiting on bqjob_r7cb929094e60fce9_0000015343908a16_17 ... (11s) Current status: DONE   
Query time: 54.2345890999 seconds.

In [224]:
cPickle.dump(positions, open('../../data/density/20150101_v2_vessels.p', 'wb'))

In [3]:
positions = cPickle.load(open('../../data/density/20150101_v2_vessels.p', 'rb'))

In [225]:
len(positions)


Out[225]:
115560

In [8]:
cellsize = 2
num_lons = 360/cellsize
num_lats = 180/cellsize

In [9]:
# first calculate a raster of vessel locations from the query

vessels = np.zeros(shape=(num_lats,num_lons)) 

for row in positions:
    lat = int(row[0])
    lon = int(row[1])
    if lat<900 and lat>-900 and lon>-1800 and lon<1800:
        lat_index = (lat+900)/(cellsize*10)
        lon_index = (lon+1800)/(cellsize*10)
        vessels[lat_index][lon_index] += 1 # one vessel

In [10]:
vessels.max()


Out[10]:
6774.0

In [19]:
# map this density

plt.rcParams["figure.figsize"] = [12,7]

cutoff = 0 # 5 degress away from the pole
firstlat = 90-cutoff
lastlat = -90+cutoff
firstlon = -180
lastlon = 180
scale = cellsize

vessel_days_truncated = vessels[cutoff/cellsize:(180/cellsize)-cutoff/cellsize][:]

numlats = int((firstlat-lastlat)/scale+.5)
numlons = int((lastlon-firstlon)/scale+.5)
    
lat_boxes = np.linspace(lastlat,firstlat,num=numlats,endpoint=False)
lon_boxes = np.linspace(firstlon,lastlon,num=numlons,endpoint=False)

fig = plt.figure()
m = Basemap(llcrnrlat=lastlat, urcrnrlat=firstlat,
          llcrnrlon=lastlon, urcrnrlon=firstlon, lat_ts=0, projection='robin',resolution="h", lon_0=0)

m.drawmapboundary(fill_color='#111111')
# m.drawcoastlines(linewidth=.2)
m.fillcontinents('#111111',lake_color='#111111')#, lake_color, ax, zorder, alpha)

x = np.linspace(-180, 180, 360/cellsize)
y = np.linspace(lastlat, firstlat, (firstlat-lastlat)/cellsize)
x, y = np.meshgrid(x, y)
converted_x, converted_y = m(x, y)
from matplotlib import colors,colorbar

maximum = 1000
minimum = .0001

norm = colors.LogNorm(vmin=minimum, vmax=maximum)
# norm = colors.Normalize(vmin=0, vmax=1000)

m.pcolormesh(converted_x, converted_y, vessel_days_truncated, norm=norm, vmin=minimum, vmax=maximum, cmap = plt.get_cmap('viridis'))

t = "Density of Vessels with AIS"
plt.title(t, color = "#000000", fontsize=18)

ax = fig.add_axes([0.2, 0.1, 0.4, 0.02]) #x coordinate , 
norm = colors.LogNorm(vmin=minimum, vmax=maximum)
# norm = colors.Normalize(vmin=0, vmax=1000)
lvls = np.logspace(np.log10(minimum),np.log10(maximum),num=8)
cb = colorbar.ColorbarBase(ax,norm = norm, orientation='horizontal', ticks=lvls, cmap = plt.get_cmap('viridis'))

the_labels = []
for l in lvls:
    if l>=1:
        l = int(l)
    the_labels.append(l)

#cb.ax.set_xticklabels(["0" ,round(m3**.5,1), m3, round(m3**1.5,1), m3*m3,round(m3**2.5,1), str(round(m3**3,1))+"+"], fontsize=10)
cb.ax.set_xticklabels(the_labels, fontsize=10, color = "#000000")
cb.set_label('Number of Vessels by 2x2 degree grid, Jan 1 2015',labelpad=-40, y=0.45, color = "#000000")

ax.text(1.7, -0.5, 'Data Source: Orbcomm\nMap by Global Fishing Watch',
        verticalalignment='bottom', horizontalalignment='right',
        transform=ax.transAxes,
        color='#000000', fontsize=6)

# plt.savefig("vessel_density_2015.png",bbox_inches='tight',dpi=300,transparent=True,pad_inches=.1, facecolor="#000000")
plt.show()



In [11]:
# create the density that is seen by satellites

def create_average_raster(filename):
    # load the file that helps with the satellite averaging
    grid_for_average = np.load(filename)
    avgs = np.zeros(shape=(num_lats,num_lons)) # 2 by 2 grid

    for i in range(num_lats):
        for j in range(num_lons):
            count = len(grid_for_average[i][j])
            total = 0
            for item in grid_for_average[i][j]:
                if vessels[item[0]][item[1]]:
                    total+= vessels[item[0]][item[1]]*(item[2]**2)
                    #total += np.log10(float(vessels[item[0]][item[1]]))#*item[2]
            avgs[i][j] = total/4.
            # divide by 4 because the satellite sees only 1/4 of the area that we're 
            #averaging over
            #avgs[i][j]=10**(float(total)/len(grid_for_average[i][j])) 

    return avgs

In [12]:
infile = '../../data/density/grid_for_average_2degree.npy'
averages = create_average_raster(infile)

In [13]:
infile = '../../data/density/grid_for_average_2degree_2000.npy'
averages_2000 = create_average_raster(infile)

In [14]:
infile = '../../data/density/grid_for_average_2degree_1500.npy'
averages_1500 = create_average_raster(infile)

In [15]:
infile = '../../data/density/grid_for_average_2degree_1000.npy'
averages_1000 = create_average_raster(infile)

In [16]:
infile = '../../data/density/grid_for_average_2degree_500.npy'
averages_500 = create_average_raster(infile)

In [27]:
# make a chart of pings versus density

def make_averages(averages,s_radius):

    den = []
    pos = []
    lats = []
    pos_weighted = []
    count = 0

    for row in positions:
        lat = int(row[2])
        lon_ave = int(row[3])
        lon_f = int(row[1])
        if abs(lon_f - lon_ave > 50): # use average, except near the dateline
            lon = lon_f
        else:
            lon = lon_ave
        sat_pos = int(row[4])
        all_pos = int(row[5])+int(row[4])
        speed = float(row[7])
        slow_pos = int(row[8])
        # must only be satellite positions
        if sat_pos == all_pos and lat<900 and lat>-900 and lon>-1800 and lon<1800 and speed>2 and slow_pos == 0:# and abs(lat)<300:
            lat_index = (lat+900)/(cellsize*10)
            lon_index = (lon+1800)/(cellsize*10)
            den.append(averages[lat_index][lon_index])
            pos_weighted.append(float(row[6]))
            pos.append(sat_pos)
            lats.append(lat)

            
    plt.rcParams["figure.figsize"] = [12,7]

    x = []
    y = []
    for d, p, l in zip(den, pos, lats):
        if p and d:# and d<10**.1:#abs(l)>0 and p and d:# and d>10**1:
            x.append(d)
            y.append(p)

    fig = plt.figure()
    ax = fig.add_subplot(1,1,1)

#     plt.scatter(np.log10(x), np.log10(y), alpha=.02
    plt.scatter(x, np.log10(y), alpha=.02
               )#, color = color)

    logA = x
    logB = np.log10(y)
    coefficients = np.polyfit(logA, logB, 1)
    polynomial = np.poly1d(coefficients)
    ys = polynomial(x)
    slope, intercept, r_value, p_value, std_err = stats.linregress(logA, logB)
    
    thetext = "slope: "+ str(round(slope,2))+"\nr_squared: "+str(round(r_value**2,2))+"\nstandard error: "+str(round(std_err,3))
    plt.scatter(x, ys, color = 'red')
    
    ax.text(2, 3.5, thetext, fontsize=10)

   # plt.xlim([0,4.5])
    plt.ylim([-.5,4])

    # print slope
    # print coefficients
    # print r_value
    # print p_value
    #print slope,std_err,p_value, r_value**2

    plt.title("Satellite positions per day versus density, Assuming Satellite Footprint of "+str(s_radius)+"km")
    plt.xlabel('Log(vessels seen by satellite)')
    plt.ylabel('Log(satellite positions)')

    plt.show()

In [28]:
make_averages(averages,2700)



In [29]:
make_averages(averages_2000,2000)



In [30]:
make_averages(averages_1500,1500)



In [31]:
make_averages(averages_1000,1000)



In [32]:
make_averages(averages_500,500)



In [539]:
# map the vessel density seen by satellite

firstlat = 90
lastlat = -90
firstlon = -180
lastlon = 180
scale = cellsize

numlats = int((firstlat-lastlat)/scale+.5)
numlons = int((lastlon-firstlon)/scale+.5)
    
lat_boxes = np.linspace(lastlat,firstlat,num=numlats,endpoint=False)
lon_boxes = np.linspace(firstlon,lastlon,num=numlons,endpoint=False)

fig = plt.figure()
plt.clf()

m = Basemap(llcrnrlat=lastlat, urcrnrlat=firstlat,
          llcrnrlon=firstlon, urcrnrlon=lastlon, lat_ts=0, projection='mill',resolution="h")

m.drawmapboundary()
m.drawcoastlines(linewidth=.2)
#m.fillcontinents('#555555')# , lake_color, ax, zorder, alpha)

x = np.linspace(-180, 180, 360/cellsize )
y = np.linspace(lastlat, firstlat, (firstlat-lastlat)/cellsize)
x, y = np.meshgrid(x, y)
converted_x, converted_y = m(x, y)

from matplotlib import colors,colorbar

norm = colors.LogNorm(vmin=1, vmax=1000)

m3 = int(averages.max()**.3333)

m.pcolormesh(converted_x, converted_y, averages, norm=norm, vmin=1, vmax=m3**3)

t = "Vessels per Day Averaged over Satellite Footprint, Jan 1, 2015"
plt.title(t)

ax = fig.add_axes([0.15, 0.1, 0.4, 0.02]) 
norm = colors.Normalize(vmin=0, vmax=1000)
norm = colors.LogNorm(vmin=1, vmax=1000)
lvls = np.logspace(0,3,7)

cb = colorbar.ColorbarBase(ax,norm = norm, orientation='horizontal', ticks=lvls)

# cb.ax.set_xticklabels(["<1" ,int(m3**.5), m3, int(m3**1.5), m3*m3,int(m3**2.5), str(int(m3**3))+"+"], fontsize=10)


plt.savefig("satellite_footprint2by2_500b.png",bbox_inches='tight',dpi=450,transparent=True,pad_inches=0)

plt.rcParams["figure.figsize"] = [12,8]

plt.show()



In [310]:
minimum = 0
maximum = 100
plt.rcParams["figure.figsize"] = [6,3]

for i in range(18):

    x = []

    plt.clf()
    if i > 0:
        minimum = maximum
    maximum += 100*i
    
    less_than_5 = 0
    count = 0
    for p, d in zip (pos, den):
        if d>minimum and d<maximum and p<500:
            x.append(p)
            if p<10:
                less_than_5 += 1
            count+=1
    plt.title("Density between "+str(minimum)+" and "+str(maximum))     
    plt.xlabel("positions per day")
    plt.ylabel("number of vessels")
    plt.hist(x, bins=50)
    plt.xlim([0,200])
    plt.show()
    print "Density between "+str(minimum)+" and "+str(maximum) + " : ", int(100*less_than_5/count)


Density between 0 and 100 :  64
Density between 100 and 200 : 
---------------------------------------------------------------------------
ZeroDivisionError                         Traceback (most recent call last)
<ipython-input-310-f35dd4444196> in <module>()
     26     plt.xlim([0,200])
     27     plt.show()
---> 28     print "Density between "+str(minimum)+" and "+str(maximum) + " : ", int(100*less_than_5/count)

ZeroDivisionError: integer division or modulo by zero

In [13]:
# okay, let's look at only fishing vessels

q = '''
SELECT
  integer(FLOOR(a_first_lat*10)) lat_bin,
  integer(FLOOR(a_first_lon*10)) lon_bin,
  integer(FLOOR(a_avg_lat*10)) lat_bin_avg,
  integer(FLOOR(a_avg_lon*10)) lon_bin_avg,
  a_satellite_positions sat_positions,
  a_positions positions
FROM
  [scratch_david_gapanalysis.ave_locations_2015_with_density_v2]
WHERE
  a_date = "2015-01-01"
  AND a_max_lat - a_min_lat <5
  AND (a_max_lon - a_min_lon < 10
    OR a_first_lon > 170
    OR a_first_lon < -170)
  AND a_mmsi IN (select mmsi from
[scratch_david_mmsi_lists.Combinedfishing_2014]
  )
'''

positions_fishing_vessels = Query(q)


Waiting on bqjob_r6a16a99088a29707_000001530ad38aee_2 ... (7s) Current status: DONE   
Query time: 16.1007111073 seconds.

In [14]:
# now make a chart of pings versus position

den = []
pos = []
count = 0

for row in positions_fishing_vessels:
    lat = int(row[2])
    lon_ave = int(row[3])
    lon_f = int(row[1])
    if abs(lon_f - lon_ave > 50): # use average, except near the dateline
        lon = lon_f
    else:
        lon = lon_ave
    sat_pos = row[4]
    all_pos = row[5]
    count += 1
    # must only be satellite positions
    if sat_pos == all_pos and lat<900 and lat>-900 and lon>-1800 and lon<1800:
        lat_index = (lat+900)/(cellsize*10)
        lon_index = (lon+1800)/(cellsize*10)
        den.append(averages[lat_index][lon_index])
        pos.append(int(sat_pos))

In [15]:
x = den
y = pos

fig = plt.figure()
ax = fig.add_subplot(1,1,1)
# ax.set_yscale('log')
# ax.set_xscale('log')

plt.scatter(np.log10(x), np.log10(y), alpha=.1)#, color = color)
# plt.scatter(x1, y1, alpha=1)#, color = color)

logA = np.log10(x)
logB = np.log10(y)
coefficients = np.polyfit(logA, logB, 1)
polynomial = np.poly1d(coefficients)
ys = polynomial(np.log10(x))
slope, intercept, r_value, p_value, std_err = stats.linregress(logA, logB)

plt.scatter(np.log10(x), ys, color = 'red')


# print slope
# print coefficients
# print r_value
# print p_value
print slope,std_err,p_value

plt.title("Satellite positions per day Versus Density FISHING VESSELS")
plt.xlabel('Log(vessels seen by satellite)')
plt.ylabel('Log(satellite positions)')

plt.show()


-0.585306674036 0.0293862270318 3.75524846468e-79

In [16]:
minimum = 0
maximum = 100

for i in range(18):

    x = []

    plt.clf()
    if i > 1:
        minimum = maximum
    maximum += 100*i

    for p, d in zip (pos, den):
        if d>minimum and d<maximum and p<400:
            x.append(p)
    plt.title("Density between "+str(minimum)+" and "+str(maximum)+", FISHING VESSELS")     
    plt.xlabel("positions per day")
    plt.ylabel("number of vessels")
    plt.hist(x, bins=50)
    plt.show()


---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-16-3feb559eade3> in <module>()
     17     plt.xlabel("positions per day")
     18     plt.ylabel("number of vessels")
---> 19     plt.hist(x, bins=50)
     20     plt.show()

/Library/Python/2.7/site-packages/matplotlib-override/matplotlib/pyplot.pyc in hist(x, bins, range, normed, weights, cumulative, bottom, histtype, align, orientation, rwidth, log, color, label, stacked, hold, **kwargs)
   2894                       histtype=histtype, align=align, orientation=orientation,
   2895                       rwidth=rwidth, log=log, color=color, label=label,
-> 2896                       stacked=stacked, **kwargs)
   2897         draw_if_interactive()
   2898     finally:

/Library/Python/2.7/site-packages/matplotlib-override/matplotlib/axes/_axes.pyc in hist(self, x, bins, range, normed, weights, cumulative, bottom, histtype, align, orientation, rwidth, log, color, label, stacked, **kwargs)
   5595         flat = np.ravel(x)
   5596         if len(flat) == 0:
-> 5597             raise ValueError("x must have at least one data point")
   5598         elif len(flat) == 1 and not binsgiven:
   5599             raise ValueError(

ValueError: x must have at least one data point

In [ ]:
# okay, let's look at averages

q = '''
SELECT
  integer(FLOOR(a_avg_lat*10)) lat_bin_avg,
  integer(FLOOR(a_avg_lon*10)) lon_bin_avg,
  avg(a_satellite_positions) sat_positions,
  count(*)
  FROM
  [scratch_david_gapanalysis.ave_locations_2015_with_density_v2]
WHERE
  a_positions = a_satellite_positions
  and a_date = "2015-01-01"
  AND a_max_lat - a_min_lat <5
  AND (a_max_lon - a_min_lon < 10)
  AND a_mmsi IN (select mmsi from
[scratch_david_mmsi_lists.Combinedfishing_2014])
GROUP BY lat_bin_avg, lon_bin_avg
'''

positions_fishing_vessels_avgs = Query(q)

In [ ]:
# now make a chart of pings versus position

den = []
pos = []

for row in positions_fishing_vessels_avgs:
    lat = int(row[0])
    lon = int(row[1])
    sat_pos = row[2]
    number = int(row[3])
    # must only be satellite positions
    if lat<900 and lat>-900 and lon>-1800 and lon<1800:
        lat_index = (lat+900)/(cellsize*10)
        lon_index = (lon+1800)/(cellsize*10)
        den.append(averages[lat_index][lon_index])
        pos.append(float(sat_pos))

In [ ]:
x = den
y = pos

fig = plt.figure()
ax = fig.add_subplot(1,1,1)
# ax.set_yscale('log')
# ax.set_xscale('log')

plt.scatter(np.log10(x), np.log10(y), alpha=.1)#, color = color)
# plt.scatter(x1, y1, alpha=1)#, color = color)

logA = np.log10(x)
logB = np.log10(y)
coefficients = np.polyfit(logA, logB, 1)
polynomial = np.poly1d(coefficients)
ys = polynomial(np.log10(x))
slope, intercept, r_value, p_value, std_err = stats.linregress(logA, logB)

plt.scatter(np.log10(x), ys, color = 'red')


# print slope
# print coefficients
# print r_value
# print p_value
print slope,std_err,p_value

plt.title("AVERAGE Satellite positions per day Versus Density FISHING VESSELS")
plt.xlabel('Log(vessels seen by satellite)')
plt.ylabel('Log(satellite positions)')

plt.show()

In [127]:



Out[127]:
1318

In [ ]: